PFE 0.33.71

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generated
(C) Guido U. Draheim
guidod@gmx.de

## ASSEMBLER

> Programming-Tools (see TOOLS-EXT)

`CODE``( "name" -- )``` => `"EXTENSIONS"`

  call `ALSO` and add ASSEMBLER wordlist if available. Add PROC ENTER assembler snippet as needed for the architecture into the PFA. The CFA is setup (a) with the PFA adress in traditional ITC or (b) with an infoblock as for sbr-coded colon words.

  Remember that not all architectures are support and that the ASSEMBLER wordset is not compiled into pfe by default. Use always the corresponding `END-CODE` for each `CODE` start. The new word name is not smudged.

  primitive code = [p4_asm_create_code]

`;CODE``( -- )``` => `"EXTENSIONS"`

  Does end the latest word (being usually some DOES> part) and enters machine-level (in EXEC-mode).

  BE AWARE: The TOOLS-EXT will not provide an `END-CODE` or any other word in the `ASSEMBLER` wordlist which is required to start any useful assembler programming. After requiring ASSEMBLER-EXT you will see a second ";CODE" in the `EXTENSIONS` wordlist that will also provide an optimized execution than the result of this standard-forth implemenation.

  The Standard-Forth implementation will actually compile a derivate of `BRANCH` into the dictionary followed by `;`. The compiled word will not jump to the target adress (following the execution token) but it will call the target adress via the host C stack. The target machine level word (C domain) will just return here for being returned (Forth domain). Hence `END-CODE` may be a simple RET, comma!

  primitive code = [p4_asm_semicolon_code]

`END-CODE``( "name" -- )``` => `"ASSEMBLER"`

  call `PREVIOUS` and add PROC LEAVE assembler snippet as needed for the architecture - usually includes bits to "return from subroutine". Remember that not all architectures are support and PFE usually does only do variants of call-threading with a separate loop for the inner interpreter that does "call into subroutine". Some forth implementations do "jump into routine" and the PROC LEAVE part would do "jump to next routine" also known as next-threading. The sbr-call-threading is usually similar to the native subroutine-coding of the host operating system. See `CODE`

  primitive code = [p4_asm_end_code]

## Block

> Words + extensions

`BLOCK``( block-u -- block-addr )``[ANS]` => `"[ANS] FORTH"`

  load the specified block into a block buffer and return the address of that block buffer - see also `BUFFER`

  primitive code = [p4_block]

`BUFFER``( block-u -- block-addr )``[ANS]` => `"[ANS] FORTH"`

  get the block buffer address for the specified block - if it had not been loaded already it is not filled with data from the disk unlike `BLOCK` does.

  primitive code = [p4_buffer]

`FLUSH``( -- )``[ANS]` => `"[ANS] FORTH"`

  call `SAVE-BUFFERS` and then unassign all block buffers with `EMPTY-BUFFERS`

  primitive code = [p4_flush]

`LOAD``( block-u -- ?? )``[FORTH]` => `"[ANS] FORTH"`

  `INTERPRET` the specified `BLOCK`

  primitive code = [p4_load]

`SAVE-BUFFERS``( -- )``[ANS]` => `"[ANS] FORTH"`

  write all modified buffer to the disk, see `UPDATE` and `FLUSH`

  primitive code = [p4_save_buffers]

`UPDATE``( -- )``[ANS]` => `"[ANS] FORTH"`

  mark the current block buffer as modified, see `FLUSH`

  primitive code = [p4_update]

`EMPTY-BUFFERS``( -- )``[ANS]` => `"[ANS] FORTH"`

  unassign all block buffers, does not even `UPDATE`

  primitive code = [p4_empty_buffers]

`LIST``( block-u -- )``[ANS]` => `"[ANS] FORTH"`

  display the block

  primitive code = [p4_list]

`THRU``( block1-u block2-u -- )``[ANS]` => `"[ANS] FORTH"`

  `LOAD` a number of block in sequence.

  primitive code = [p4_thru]

## BLOCK-Misc

> Compatibility words

`CLOSE-BLOCKFILE``( -- )``[FTH] w32for` => `[FORTH]`

  w32for-implementation:

        blockhandle -1 <> if flush close-file drop then
        -1 set-blockfile

  in pfe:

        : CLOSE-BLOCKFILE
          BLOCK-FILE ?DUP IF FLUSH CLOSE-FILE DROP THEN
          OFF> BLOCK-FILE ;

  primitive code = [p4_close_blockfile]

`OPEN-BLOCKFILE``( "filename" -- )``[FTH] w32for` => `[FORTH]`

  w32for-implementation:

          close-blockfile
          parse-word r/w open-file abort" failed to open block-file"
          set-blockfile
          empty-buffers

  primitive code = [p4_open_blockfile]

`CREATE-BLOCKFILE``( blocks-count "filename" -- )``[FTH] w32for` => `[FORTH]`

  w32for-implementation:

          close-blockfile
          parse-word r/w create-file abort" failed to create block-file"
          set-blockfile
          dup b/buf m* blockhandle resize-file
          abort" unable to create a file of that size"
          empty-buffers
          0 do i wipe loop
          flush

  pfe does not wipe the buffers

  primitive code = [p4_create_blockfile]

`SET-BLOCKFILE``( block-file* -- )``[EXT] win32for` => `"EXTENSIONS"`

  win32forth uses a system-filedescriptor where -1 means unused in the BLOCKHANDLE, but we use a "FILE*"-like structure, so NULL means NOT-IN-USE. Here we set it.

  primitive code = [p4_set_blockfile]

`0 CREATE-BLOCKFILE``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_zero_create_blockfile]

## C-preprocessor

> declaration syntax

`#ELSE``( -- )``[FTH]` => `"FORTH"`

  The implementation of #ELSE is done in C for speed and being less error prone. Better use the ANSI-compatible `[IF]` `[ELSE]` `[THEN]` construct.

  immediate code = [p4_sh_else]

`#ENDIF``( -- )``[FTH]` => `"FORTH"`

  end of `#IF` `#IFDEF` `#IFNOTDEF` and `#ELSE` contructs

          (a dummy word that does actually nothing, but #ELSE may look for it)

  immediate code = [p4_sh_endif]

`#IF``( -- C: state-save-flag mfth-if-magic S: )``[FTH]` => `"FORTH"`

  prepares for a following `#IS_TRUE` or `#IS_FALSE`, does basically switch off compile-mode for the enclosed code. better use the ANSI style `[IF]` `[ELSE]` `[THEN]` construct.

  immediate code = [p4_sh_if]

`#IFDEF``( "word" -- )``[FTH]` => `"FORTH"`

  better use `[DEFINED] word [IF]` - the word `[IF]` is ANSI-conform.

  immediate code = [p4_sh_ifdef]

`#IFNDEF``` => `"FORTH"`

  (no description)

  immediate code = [p4_sh_ifnotdef]

`#IFNOTDEF``( "word" -- )``[FTH]` => `"FORTH"`

  better use `[DEFINED] word [NOT] [IF]` - the word `[IF]` and `[ELSE]` are ANSI-conform, while `#IFDEF` `#ELSE` are not.

  immediate code = [p4_sh_ifnotdef]

`#IS_TRUE``( C: state-save-flag mfth-if-magic S: test-flag -- )``[FTH]` => `"FORTH"`

  checks the condition on the `CS-STACK`. Pairs with `#IF` better use the ANSI style `[IF]` `[ELSE]` `[THEN]` construct.

  immediate code = [p4_sh_is_true]

`#IS_FALSE``( C: state-save-flag mfth-if-magic S: test-flag -- )``[FTH]` => `"FORTH"`

  checks the condition on the `CS-STACK`. Pairs with `#IF` better use the ANSI style `[IF]` `[ELSE]` `[THEN]` construct.

  immediate code = [p4_sh_is_false]

`#DEFINE``` => `"FORTH"`

  (no description)

  primitive code = [p4_sh_define]

`#PRAGMA``` => `"FORTH"`

  (no description)

  primitive code = [p4_sh_pragma]

## chain

> of executions

`link,``( some-list* -- )``[EXT]` => `"EXTENSIONS"`

        : link,        here over @ a, swap ! ;

  primitive code = [p4_link_comma]

`.chain``( some-chain* -- )``[EXT]` => `"EXTENSIONS"`

  show chain - compare with `WORDS`

  primitive code = [p4_dot_chain]

`.chains``( -- )``[EXT]` => `"EXTENSIONS"`

  show all chains registered in the system - compare with `VLIST`

  primitive code = [p4_dot_chains]

`chain-add``( some-chain* "word-to-add" -- )``[EXT]` => `"EXTENSIONS"`

  add chain item, for normal setup, at end of do-chain

        : chain-add ' >r begin dup @ while @ repeat here swap ! 0 , r> , ;
        ( chain-add begin dup @ while @ repeat  here swap ! 0, ' , )

  primitive code = [p4_chain_add]

`chain-add-before``( some-chain* "word-to-add" -- )``[EXT]` => `"EXTENSIONS"`

  add chain item, for reverse chain like BYE

        : chain-add-before ' >r here over @ , r> , swap ! ;
        ( chain-add-before link, ' , )

  primitive code = [p4_chain_add_before]

`do-chain``( some-chain* -- )``[EXT]` => `"EXTENSIONS"`

  execute chain

        : do-chain being @ ?dup while dup>r cell+ @execute r> repeat ;

  primitive code = [p4_do_chain]

## chainlists

> - executable wordlists

`NEW-WORDLIST``( "name" -- )``[EXT] [DOES: -- new-wordlist* ]` => `"EXTENSIONS"`

  create a new `WORDLIST` and a "name" with a runtime of ( -- wordlist* )

        : NEW-WORDLIST WORDLIST VALUE ;
        : NEW-WORDLIST CREATE: WORDLIST ;

  usually used for `DO-ALL-WORDS` / `DO-SYNONYM`

  primitive code = [p4_new_wordlist]

`.WORDS``( some-wordlist* -- )``[EXT]` => `"EXTENSIONS"`

  print the `WORDLIST` interactivly to the user

        : .WORDS ALSO SET-CONTEXT WORDS PREVIOUS ;

  `WORDS` / `ORDER` / `NEW-WORDLIST` / `DO-ALL-WORDS`

  primitive code = [p4_dot_words]

`REDO-ALL-WORDS``( some-wordlist* -- )``[EXT]` => `"EXTENSIONS"`

  `EXECUTE` each entry in the wordlist in the original order defined

        : REDO-ALL-WORDS
             0 FIRST-NAME
             0 SWAP ( under )
             BEGIN ?DUP WHILE
                DUP NAME> SWAP ( under )
                NAME-NEXT
             REPEAT
             BEGIN ?DUP WHILE
                EXECUTE
             REPEAT
        ;

  to run the `NEW-WORDLIST` in last-run-first order, use `DO-ALL-WORDS`

  primitive code = [p4_redo_all_words]

`DO-ALL-WORDS``( some-wordlist* -- )``[EXT]` => `"EXTENSIONS"`

  `EXECUTE` each entry in the wordlist in the reverse order defined

        : DO-ALL-WORDS
             0 FIRST-NAME
             BEGIN ?DUP WHILE
                DUP NAME> EXECUTE
                NAME-NEXT
             REPEAT
        ;

  to run the `NEW-WORDLIST` in original order, use `REDO-ALL-WORDS`

  primitive code = [p4_do_all_words]

`DO-ALL-WORDS-WHILE-LOOP``( some-wordlist* test-xt* -- )``[EXT]` => `"EXTENSIONS"`

  `EXECUTE` each entry in the wordlist in the reverse order defined but only as long as after EXECUTE of "word" a TRUE flag is left on the stack. The wordlist execution is cut when a FALSE flag is seen. (the current wordlist entry is _not_ on the stack!)

        : DO-ALL-WORDS-WHILE-LOOP >R
             0 FIRST-NAME
             BEGIN ?DUP WHILE
                R@ EXECUTE 0= IF R>DROP DROP EXIT THEN
                DUP NAME> EXECUTE
                NAME-NEXT
             REPEAT R>DROP
        ;

  compare with `DO-ALL-WORDS-WHILE`

  primitive code = [p4_do_all_words_while_loop]

`DO-ALL-WORDS-WHILE``( some-wordlist* "word" -- )``[EXT]` => `"EXTENSIONS"`

  `EXECUTE` each entry in the wordlist in the reverse order defined but only as long as after EXECUTE of "word" a TRUE flag is left on the stack. The wordlist execution is cut when a FALSE flag is seen. (the current wordlist entry is _not_ on the stack!)

        : DO-ALL-WORDS-WHILE '
             STATE @ IF LITERAL, COMPILE DO-ALL-WORDS-WHILE-LOOP EXIT THEN
             >R 0 FIRST-NAME
             BEGIN ?DUP WHILE
                R@ EXECUTE 0= IF R>DROP DROP EXIT THEN
                DUP NAME> EXECUTE
                NAME-NEXT
             REPEAT R>DROP
        ;

  to run the `NEW-WORDLIST` in original order, use `REDO-ALL-WORDS`

  compiling word = [p4_do_all_words_while]

`DO-SYNONYM``( some-wordlist* "do-name" "orig-name" -- )``[EXT]` => `"EXTENSIONS"`

  create a `SYNONYM` in the specified wordlist.

        : DO-SYNONYM GET-CURRENT SWAP SET-CURRENT SYNONYM SET-CURRENT ;

  `DO-ALIAS` / `DO-ALL-WORDS` / `NEW-WORDLIST` / `WORDLIST` / `ORDER`

  primitive code = [p4_do_synonym]

`DO-ALIAS``( some-xt* definition-wordlist* "do-name" -- )``[EXT]` => `"EXTENSIONS"`

  create an `ALIAS` with the exec-token in the specified wordlist

        : DO-ALIAS GET-CURRENT SWAP SET-CURRENT SWAP ALIAS SET-CURRENT ;

  `DO-SYNONYM`

  primitive code = [p4_do_alias]

`ALIAS-ATEXIT``( some-xt* "name" -- )``[EXT]` => `"EXTENSIONS"`

  create a defer word that is initialized with the given x-token.

        : ALIAS-ATEXIT ATEXIT-WORDLIST DO-ALIAS ;

  `ATEXIT-WORDLIST` `DO-ALL-WORDS`

  primitive code = [p4_alias_atexit]

## Complex

> floating point

`R2P1``` => `"EXTENSIONS"`

  (no description)

  primitive code = [r2p1]

`T2P1``` => `"EXTENSIONS"`

  (no description)

  primitive code = [t2p1]

`LAMBDA/EPSILON``` => `"EXTENSIONS"`

  (no description)

  primitive code = [lambda_slash_epsilon]

`Z@``( addr -- f: z )``` => `"EXTENSIONS"`

  primitive code = [p4_z_fetch]

`Z!``( addr f: z -- )``` => `"EXTENSIONS"`

  primitive code = [p4_z_store]

`X@``( zaddr -- f: x )``` => `"EXTENSIONS"`

  primitive code = [p4_x_fetch]

`X!``( zaddr f: x -- )``` => `"EXTENSIONS"`

  primitive code = [p4_x_store]

`Y@``( zaddr -- f: y )``` => `"EXTENSIONS"`

  primitive code = [p4_y_fetch]

`Y!``( zaddr f: x -- )``` => `"EXTENSIONS"`

  primitive code = [p4_y_store]

`Z.``(f: z -- )``` => `"EXTENSIONS"`

  Emit the complex number, including the sign of zero when `signbit()` is available.

  primitive code = [p4_z_dot]

`ZS.``(f: z -- )``` => `"EXTENSIONS"`

  Emit the complex number in scientific notation, including the sign of zero when `signbit()` is available.

  primitive code = [p4_z_s_dot]

`REAL``(f: x y -- x )``` => `"EXTENSIONS"`

  primitive code = [p4_real]

`IMAG``(f: x y -- y )``` => `"EXTENSIONS"`

  primitive code = [p4_imag]

`CONJG``(f: x y -- x -y )``` => `"EXTENSIONS"`

  primitive code = [p4_conjg]

`ZDROP``(f: z -- )``` => `"EXTENSIONS"`

  primitive code = [p4_z_drop]

`ZDUP``(f: z -- z z )``` => `"EXTENSIONS"`

  primitive code = [p4_z_dup]

`ZSWAP``(f: z1 z2 -- z2 z1 )``` => `"EXTENSIONS"`

  primitive code = [p4_z_swap]

`ZOVER``(f: z1 z2 -- z1 z2 z1 )``` => `"EXTENSIONS"`

  primitive code = [p4_z_over]

`ZNIP``(f: z1 z2 -- z2 )``` => `"EXTENSIONS"`

  primitive code = [p4_z_nip]

`ZTUCK``(f: z1 z2 -- z2 z1 z2 )``` => `"EXTENSIONS"`

  primitive code = [p4_z_tuck]

`ZROT``(f: z1 z2 z3 -- z2 z3 z1 )``` => `"EXTENSIONS"`

  primitive code = [p4_z_rot]

`-ZROT``(f: z1 z2 z3 -- z3 z1 z2 )``` => `"EXTENSIONS"`

  primitive code = [p4_minus_z_rot]

`Z+``(f: z1 z2 -- z1+z2 )``` => `"EXTENSIONS"`

  primitive code = [p4_z_plus]

`Z-``(f: z1 z2 -- z1-z2 )``` => `"EXTENSIONS"`

  primitive code = [p4_z_minus]

`Z*``(f: x y u v -- x*u-y*v x*v+y*u )``` => `"EXTENSIONS"`

  Uses the algorithm followed by JVN: (x+iy)*(u+iv) = [(x+y)*u - y*(u+v)] + i[(x+y)*u + x*(v-u)] Requires 3 multiplications and 5 additions.

  primitive code = [p4_z_star]

`Z/``(f: u+iv z -- u/z+iv/z )``` => `"EXTENSIONS"`

  Kahan-like algorithm *without* due attention to spurious over/underflows and zeros and infinities.

  primitive code = [p4_z_slash]

`ZNEGATE``(f: z -- -z )``` => `"EXTENSIONS"`

  primitive code = [p4_z_negate]

`Z2*``(f: z -- z*2 )``` => `"EXTENSIONS"`

  primitive code = [p4_z_two_star]

`Z2/``(f: z -- z/2 )``` => `"EXTENSIONS"`

  primitive code = [p4_z_two_slash]

`I*``(f: x y -- -y x )``` => `"EXTENSIONS"`

  primitive code = [p4_i_star]

`-I*``(f: x y -- y -x )``` => `"EXTENSIONS"`

  primitive code = [p4_minus_i_star]

`1/Z``(f: z -- 1/z )``` => `"EXTENSIONS"`

  Kahan algorithm *without* due attention to spurious over/underflows and zeros and infinities.

  primitive code = [p4_one_slash_z]

`Z^2``(f: z -- z^2 )``` => `"EXTENSIONS"`

  Kahan algorithm without removal of any spurious NaN created by overflow. It deliberately uses (x-y)(x+y) instead of x^2-y^2 for the real part.

  primitive code = [p4_z_hat_two]

`|Z|^2``(f: x y -- |z|^2 )``` => `"EXTENSIONS"`

  primitive code = [p4_z_abs_hat_two]

`Z^N``( n f: z -- z^n )``` => `"EXTENSIONS"`

  primitive code = [p4_z_hat_n]

`X+``(f: z a -- x+a y )``` => `"EXTENSIONS"`

  primitive code = [p4_x_plus]

`X-``(f: z a -- x-a y )``` => `"EXTENSIONS"`

  primitive code = [p4_x_minus]

`Y+``(f: z a -- x y+a )``` => `"EXTENSIONS"`

  primitive code = [p4_y_plus]

`Y-``(f: z a -- x y-a )``` => `"EXTENSIONS"`

  primitive code = [p4_y_minus]

`Z*F``(f: x y f -- x*f y*f )``` => `"EXTENSIONS"`

  primitive code = [p4_z_star_f]

`Z/F``(f: x y f -- x/f y/f )``` => `"EXTENSIONS"`

  primitive code = [p4_z_slash_f]

`F*Z``(f: f x y -- f*x f*y )``` => `"EXTENSIONS"`

  primitive code = [p4_f_star_z]

`F/Z``(f: f z -- f/z )``` => `"EXTENSIONS"`

  Kahan algorithm *without* due attention to spurious over/underflows and zeros and infinities.

  primitive code = [p4_f_slash_z]

`Z*I*F``(f: z f -- z*if )``` => `"EXTENSIONS"`

  primitive code = [p4_z_star_i_star_f]

`-I*Z/F``(f: z f -- z/[if] )``` => `"EXTENSIONS"`

  primitive code = [p4_minus_i_star_z_slash_f]

`I*F*Z``(f: f z -- if*z )``` => `"EXTENSIONS"`

  primitive code = [p4_i_star_f_star_z]

`I*F/Z``(f: f z -- [0+if]/z )``` => `"EXTENSIONS"`

  Kahan algorithm *without* due attention to spurious over/underflows and zeros and infinities.

  primitive code = [p4_i_star_f_slash_z]

`Z*>REAL``(f: z1 z2 -- Re[z1*z2] )``` => `"EXTENSIONS"`

  Compute the real part of the complex product without computing the imaginary part. Recommended by Kahan to avoid gratuitous overflow or underflow signals from the unnecessary part.

  primitive code = [p4_z_star_to_real]

`Z*>IMAG``(f: z1 z2 -- Im[z1*z2] )``` => `"EXTENSIONS"`

  Compute the imaginary part of the complex product without computing the real part.

  primitive code = [p4_z_star_to_imag]

`|Z|``(f: x y -- |z| )``` => `"EXTENSIONS"`

  primitive code = [p4_z_abs]

`ZBOX``(f: z -- box[z] )``` => `"EXTENSIONS"`

  Defined *only* for zero and infinite arguments. This difffers from Kahan's `CBOX` [p. 198] by conserving signs when only one of x or y is infinite, consistent with the other cases, and with its use in his `ARG` [p. 199].

  primitive code = [p4_z_box]

`ARG``(f: z -- principal.arg[z] )``` => `"EXTENSIONS"`

  primitive code = [p4_arg]

`>POLAR``(f: x y -- r theta )``` => `"EXTENSIONS"`

  Convert the complex number z to its polar representation, where theta is the principal argument.

  primitive code = [p4_to_polar]

`POLAR>``(f: r theta -- x y )``` => `"EXTENSIONS"`

  primitive code = [p4_polar_from]

`ZSSQS``(f: z -- rho s: k )``` => `"EXTENSIONS"`

  Compute rho = |(x+iy)/2^k|^2, scaled to avoid overflow or underflow, and leave the scaling integer k. Kahan, p. 200.

  primitive code = [p4_z_ssqs]

`ZSQRT``(f: z -- sqrt[z] )``` => `"EXTENSIONS"`

  Compute the principal branch of the square root, with Re sqrt[z] >= 0. Kahan, p. 201.

  primitive code = [p4_z_sqrt]

`ZLN``(f: z -- ln|z|+i*theta )``` => `"EXTENSIONS"`

  Compute the principal branch of the complex natural logarithm. The angle theta is the principal argument. This code uses Kahan's algorithm for the scaled logarithm `CLOGS(z,J)` = ln(z*2^J), with J=0 and blind choices of the threshholds T0, T1, and T2. Namely, T0 = 1/sqrt(2), T1 = 5/4, and T2 = 3;

  primitive code = [p4_z_ln]

`ZEXP``(f: z -- exp[z] )``` => `"EXTENSIONS"`

  primitive code = [p4_z_exp]

`Z^``(f: x y u v -- [x+iy]^[u+iv] )``` => `"EXTENSIONS"`

  Compute in terms of the principal argument of x+iy.

  primitive code = [p4_z_hat]

`ZCOSH``(f: z -- cosh[z] )``` => `"EXTENSIONS"`

  primitive code = [p4_z_cosh]

`ZSINH``(f: z -- sinh[z] )``` => `"EXTENSIONS"`

  primitive code = [p4_z_sinh]

`ZTANH``(f: z -- tanh[z] )``` => `"EXTENSIONS"`

  Kahan, p. 204, including his divide by zero signal suppression for infinite values of `tan()`. To quote the very informative "=>'man math'" on our Darwin system about IEEE 754: "Divide-by-Zero is signaled only when a function takes exactly infinite values at finite operands."

  primitive code = [p4_z_tanh]

`ZCOTH``(f: z -- 1/tanh[z] )``` => `"EXTENSIONS"`

  primitive code = [p4_z_coth]

`ZCOS``(f: z -- cosh[i*z] )``` => `"EXTENSIONS"`

  primitive code = [p4_z_cos]

`ZSIN``(f: z -- -i*sinh[i*z] )``` => `"EXTENSIONS"`

  primitive code = [p4_z_sin]

`ZTAN``(f: z -- -i*tanh[i*z] )``` => `"EXTENSIONS"`

  primitive code = [p4_z_tan]

`ZCOT``(f: z -- -i*coth[-i*z] )``` => `"EXTENSIONS"`

  primitive code = [p4_z_cot]

`ZACOS``(f: z -- u+iv=acos[z] )``` => `"EXTENSIONS"`

  Kahan, p.202.

  primitive code = [p4_z_acos]

`ZACOSH``(f: z -- u+iv=acosh[z] )``` => `"EXTENSIONS"`

  Kahan, p.203.

  primitive code = [p4_z_acosh]

`ZASIN``(f: z -- u+iv=asin[z] )``` => `"EXTENSIONS"`

  Kahan, p.203.

  primitive code = [p4_z_asin]

`ZASINH``(f: z -- -i*asin[i*z] )``` => `"EXTENSIONS"`

  Kahan, p. 203, couth.

  primitive code = [p4_z_asinh]

`ZATANH``(f: z -- u+iv=atanh[z] )``` => `"EXTENSIONS"`

  Kahan, p. 203.

  primitive code = [p4_z_atanh]

`ZATAN``(f: z -- -i*atanh[i*z] )``` => `"EXTENSIONS"`

  Kahan, p. 204, couth.

  primitive code = [p4_z_atan]

`ZLITERAL``` => `"EXTENSIONS"`

  (no description)

  compiling word = [p4_z_literal]

## Core

> words + extensions

`!``( value some-cell* -- | value addr* -- [?] )``[ANS]` => `"[ANS] FORTH"`

  store value at addr (sizeof `CELL`)

  primitive code = [p4_store]

`#``( n,n -- n,n' )``[ANS]` => `"[ANS] FORTH"`

  see also `HOLD` for old-style forth-formatting words and `PRINTF` of the C-style formatting - this word divides the argument by `BASE` and add it to the picture space - it should be used inside of `<#` and `#>`

  primitive code = [p4_sh]

`#>``( n,n -- hold-str-ptr hold-str-len )``[ANS]` => `"[ANS] FORTH"`

  see also `HOLD` for old-style forth-formatting words and `PRINTF` of the C-style formatting - this word drops the argument and returns the picture space buffer

  primitive code = [p4_sh_greater]

`#S``( n,n -- 0,0 )``[ANS]` => `"[ANS] FORTH"`

  see also `HOLD` for old-style forth-formatting words and `PRINTF` of the C-style formatting - this word does repeat the word `#` for a number of times, until the argument becomes zero. Hence the result is always null - it should be used inside of `<#` and `#>`

  primitive code = [p4_sh_s]

`(``( 'comment<closeparen>' -- )``[ANS]` => `"[ANS] FORTH"`

  eat everything up to the next closing paren - treat it as a comment.

  immediate code = [p4_paren]

`*``( a# b# -- mul-a#' | a b -- mul-a' [??] )``[ANS]` => `"[ANS] FORTH"`

  return the multiply of the two args

  primitive code = [p4_star]

`*/``( a# b# c# -- scale-a#' | a b c -- scale-a' [??] )``[ANS]` => `"[ANS] FORTH"`

  regard the b/c as element Q - this word has an advantage over the sequence of `*` and `/` by using an intermediate double-cell value

  primitive code = [p4_star_slash]

`*/MOD``( a# b# c# -- div-a# mod-a# | a b c -- div-a mod-a [??] )``[ANS]` => `"[ANS] FORTH"`

  has an adavantage over the sequence of `*` and `/MOD` by using an intermediate double-cell value.

  primitive code = [p4_star_slash_mod]

`+``( a* b# -- a*' | a# b* -- b*' | a# b# -- a#' | a b -- a' [??] )``[ANS]` => `"[ANS] FORTH"`

  return the sum of the two args

  primitive code = [p4_plus]

`+!``( value# some-cell* -- | value some* -- [?] )``[ANS]` => `"[ANS] FORTH"`

  add val to the value found in addr

        simulate:
          : +! TUCK @ + SWAP ! ;

  primitive code = [p4_plus_store]

`+LOOP``( increment# R: some,loop -- )``[ANS]` => `"[ANS] FORTH"`

  compile `((+LOOP))` which will use the increment as the loop-offset instead of just 1. See the `DO` and `LOOP` construct.

  compiling word = [p4_plus_loop]

`,``( value* -- | value# -- | value -- [?] )``[ANS]` => `"[ANS] FORTH"`

  store the value in the dictionary

        simulate:
          : , DP  1 CELLS DP +!  ! ;

  primitive code = [p4_comma]

`-``( a* b# -- a*' | a# b* -- b*' | a# b# -- a#' | a* b* -- diff-b#' | a b -- a' [??] )``[ANS]` => `"[ANS] FORTH"`

  return the difference of the two arguments

  primitive code = [p4_minus]

`.``( value# -- | value* -- [?] | value -- [??] )``[ANS]` => `"[ANS] FORTH"`

  print the numerical value to stdout - uses `BASE`

  primitive code = [p4_dot]

`."``( [string<">] -- )``[ANS]` => `"[ANS] FORTH"`

  print the string to stdout

  compiling word = [p4_dot_quote]

`/``( a# b# -- a#' | a b -- a' [???] )``[ANS]` => `"[ANS] FORTH"`

  return the quotient of the two arguments

  primitive code = [p4_slash]

`/MOD``( a# b# -- div-a#' mod-a#' | a b -- div-a' mod-a' [??] )``[ANS]` => `"[ANS] FORTH"`

  divide a and b and return both quotient n and remainder m

  primitive code = [p4_slash_mod]

`0<``( value -- test-flag )``[ANS]` => `"[ANS] FORTH"`

  return a flag that is true if val is lower than zero

        simulate:
         : 0< 0 < ;

  primitive code = [p4_zero_less]

`0=``( 0 -- test-flag! | value! -- 0 | value -- test-flag )``[ANS]` => `"[ANS] FORTH"`

  return a flag that is true if val is just zero

        simulate:
         : 0= 0 = ;

  primitive code = [p4_zero_equal]

`1+``( value -- value' )``[ANS]` => `"[ANS] FORTH"`

  return the value incremented by one

        simulate:
         : 1+ 1 + ;

  primitive code = [p4_one_plus]

`1-``( value -- value' )``[ANS]` => `"[ANS] FORTH"`

  return the value decremented by one

        simulate:
          : 1- 1 - ;

  primitive code = [p4_one_minus]

`2!``( x,x variable* -- )``[ANS]` => `"[ANS] FORTH"`

  double-cell store

  primitive code = [p4_two_store]

`2*``( a# -- a#' | a -- a' [??] )``[ANS]` => `"[ANS] FORTH"`

  multiplies the value with two - but it does actually use a shift1 to be faster

        simulate:
         : 2* 2 * ; ( canonic) : 2* 1 LSHIFT ; ( usual)

  primitive code = [p4_two_star]

`2/``( a# -- a#' | a -- a' [??] )``[ANS]` => `"[ANS] FORTH"`

  divides the value by two - but it does actually use a shift1 to be faster

        simulate:
         : 2/ 2 / ; ( canonic) : 2/ 1 RSHIFT ; ( usual)

  primitive code = [p4_two_slash]

`2@``( variable* -- x,x )``[ANS]` => `"[ANS] FORTH"`

  double-cell fetch

  primitive code = [p4_two_fetch]

`2DROP``( a b -- )``[ANS]` => `"[ANS] FORTH"`

  double-cell drop, also used to drop two items

  primitive code = [p4_two_drop]

`2DUP``( a,a -- a,a a,a )``[ANS]` => `"[ANS] FORTH"`

  double-cell duplication, also used to duplicate two items

        simulate:
          : 2DUP OVER OVER ; ( wrong would be : 2DUP DUP DUP ; !!)

  primitive code = [p4_two_dup]

`2OVER``( a,a b,b -- a,a b,b a,a )``[ANS]` => `"[ANS] FORTH"`

  double-cell over, see `OVER` and `2DUP`

        simulate:
          : 2OVER SP@ 2 CELLS + 2@ ;

  primitive code = [p4_two_over]

`2SWAP``( a,a b,b -- b,b a,a )``[ANS]` => `"[ANS] FORTH"`

  double-cell swap, see `SWAP` and `2DUP`

        simulate:
          : 2SWAP LOCALS| B1 B2 A1 A2 | B2 B1 A2 A1 ;

  primitive code = [p4_two_swap]

`;``( -- )``[ANS] [EXIT] [END]` => `"[ANS] FORTH"`

  compiles `((;))` which does `EXIT` the current colon-definition. It does then end compile-mode and returns to execute-mode. See `:` and `:NONAME`

  compiling word = [p4_semicolon]

`<``( a* b* -- test-flag | a# b# -- test-flag | a b -- test-flag [?] )``[ANS]` => `"[ANS] FORTH"`

  return a flag telling if a is lower than b

  primitive code = [p4_less_than]

`<#``( -- )``[ANS]` => `"[ANS] FORTH"`

  see also `HOLD` for old-style forth-formatting words and `PRINTF` of the C-style formatting - this word does initialize the pictured numeric output space.

  primitive code = [p4_less_sh]

`=``( a* b* -- test-flag | a# b# -- test-flag | a b -- test-flag [?] )``[ANS]` => `"[ANS] FORTH"`

  return a flag telling if a is equal to b

  primitive code = [p4_equals]

`>``( a* b* -- test-flag | a# b# -- test-flag | a b -- test-flag [?] )``[ANS]` => `"[ANS] FORTH"`

  return a flag telling if a is greater than b

  primitive code = [p4_greater_than]

`>BODY``( some-xt* -- some-body* )``[ANS]` => `"[ANS] FORTH"`

  adjust the execution-token (ie. the CFA) to point to the parameter field (ie. the PFA) of a word. this is not a constant operation - most words have their parameters at "1 CELLS +" but CREATE/DOES-words have the parameters at "2 CELLS +" and ROM/USER words go indirect with a rom'ed offset i.e. "CELL + @ UP +"

  primitive code = [p4_to_body]

`>NUMBER``( a,a str-ptr str-len -- a,a' str-ptr' str-len)``[ANS]` => `"[ANS] FORTH"`

  try to convert a string into a number, and place that number at a,a respeciting `BASE`

  primitive code = [p4_to_number]

`>R``( value -- R: value )``[ANS]` => `"[ANS] FORTH"`

  save the value onto the return stack. The return stack must be returned back to clean state before an exit and you should note that the return-stack is also touched by the `DO` ... `WHILE` loop. Use `R>` to clean the stack and `R@` to get the last value put by `>R`

  compiling word = [p4_to_r]

`?DUP``( 0 -- 0 | value! -- value! value! | value -- 0 | value! value! )``[ANS]` => `"[ANS] FORTH"`

  one of the rare words whose stack-change is condition-dependet. This word will duplicate the value only if it is not zero. The usual place to use it is directly before a control-word that can go to different places where we can spare an extra `DROP` on the is-null-part. This makes the code faster and often a little easier to read.

        example:
          : XX BEGIN ?DUP WHILE DUP . 2/ REPEAT ; instead of
          : XX BEGIN DUP WHILE DUP . 2/ REPEAT DROP ;

  primitive code = [p4_Q_dup]

`@``( value* -- value )``[ANS]` => `"[ANS] FORTH"`

  fetch the value from the variables address

  primitive code = [p4_fetch]

`ABS``( value# -- value#' )``[ANS]` => `"[ANS] FORTH"`

  return the absolute value

  primitive code = [p4_abs]

`ACCEPT``( buffer-ptr buffer-max -- buffer-len )``[ANS]` => `"[ANS] FORTH"`

  get a string from terminal into the named input buffer, returns the number of bytes being stored in the buffer. May provide line-editing functions.

  primitive code = [p4_accept]

`ALIGN``( -- )``[ANS]` => `"[ANS] FORTH"`

  will make the dictionary aligned, usually to a cell-boundary, see `ALIGNED`

  primitive code = [p4_align]

`ALIGNED``( addr -- addr' )``[ANS]` => `"[ANS] FORTH"`

  uses the value (being usually a dictionary-address) and increment it to the required alignment for the dictionary which is usually in `CELLS` - see also `ALIGN`

  primitive code = [p4_aligned]

`ALLOT``( allot-count -- )``[ANS]` => `"[ANS] FORTH"`

  make room in the dictionary - usually called after a `CREATE` word like `VARIABLE` or `VALUE` to make for an array of variables. Does not initialize the space allocated from the dictionary-heap. The count is in bytes - use `CELLS` ALLOT to allocate a field of cells.

  primitive code = [p4_allot]

`AND``( value mask -- value' )``[ANS]` => `"[ANS] FORTH"`

  mask with a bitwise and - be careful when applying it to logical values.

  primitive code = [p4_and]

`BEGIN``( -- )``[ANS] [LOOP]` => `"[ANS] FORTH"`

  start a control-loop, see `WHILE` and `REPEAT`

  compiling word = [p4_begin]

`C!``( value# variable#* -- | value# variable* [?] )``[ANS]` => `"[ANS] FORTH"`

  store the byte-value at address, see => !

  primitive code = [p4_c_store]

`C,``( value# -- )``[ANS]` => `"[ANS] FORTH"`

  store a new byte-value in the dictionary, implicit 1 ALLOT, see => ,

  primitive code = [p4_c_comma]

`C@``( value#* -- value# | value* -- value# [?] )``[ANS]` => `"[ANS] FORTH"`

  fetch a byte-value from the address, see `@`

  primitive code = [p4_c_fetch]

`CELL+``( value -- value' )``[ANS]` => `"[ANS] FORTH"`

  adjust the value by adding a single Cell's width - the value is often an address or offset, see `CELLS`

  primitive code = [p4_cell_plus]

`CELLS``( value# -- value#' )``[ANS]` => `"[ANS] FORTH"`

  scale the value by the sizeof a Cell the value is then often applied to an address or fed into `ALLOT`

  primitive code = [p4_cells]

`CHAR``( 'word' -- char# )``[ANS]` => `"[ANS] FORTH"`

  return the (ascii-)value of the following word's first character.

  primitive code = [p4_char]

`CHAR+``( value -- value' )``[ANS]` => `"[ANS] FORTH"`

  increment the value by the sizeof one char - the value is often a pointer or an offset, see `CHARS`

  primitive code = [p4_char_plus]

`CHARS``( value# -- value#' )``[ANS]` => `"[ANS] FORTH"`

  scale the value by the sizeof a char - the value is then often applied to an address or fed into `ALLOT` (did you expect that sizeof(p4char) may actually yield 2 bytes?)

  primitive code = [p4_chars]

`COUNT``( string-bstr* -- string-ptr' string-len | some* -- some*' some-len [?] )``[ANS]` => `"[ANS] FORTH"`

  usually before calling `TYPE`

  (as an unwarranted extension, this word does try to be idempotent).

  primitive code = [p4_count]

`CR``( -- )``[ANS]` => `"[ANS] FORTH"`

  print a carriage-return/new-line on stdout

  primitive code = [p4_cr]

`DECIMAL``( -- )``[ANS]` => `"[ANS] FORTH"`

  set the `BASE` to 10

        simulate:
          : DECIMAL 10 BASE ! ;

  primitive code = [p4_decimal]

`DEPTH``( -- depth# )``[ANS]` => `"[ANS] FORTH"`

  return the depth of the parameter stack before the call, see `SP@` - the return-value is in `CELLS`

  primitive code = [p4_depth]

`DO``( end# start# | end* start* -- R: some,loop )``[ANS] [LOOP]` => `"[ANS] FORTH"`

  pushes $end and $start onto the return-stack ( `>R` ) and starts a control-loop that ends with `LOOP` or `+LOOP` and may get a break-out with `LEAVE` . The loop-variable can be accessed with `I`

  compiling word = [p4_do]

`DOES>``( -- does* )``[ANS] [END] [NEW]` => `"[ANS] FORTH"`

  does twist the last `CREATE` word to carry the `(DOES>)` runtime. That way, using the word will execute the code-piece following `DOES>` where the pfa of the word is already on stack. (note: FIG option will leave pfa+cell since does-rt is stored in pfa)

  compiling word = [p4_does]

`DROP``( a -- )``[ANS]` => `"[ANS] FORTH"`

  just drop the word on the top of stack, see `DUP`

  primitive code = [p4_drop]

`DUP``( a -- a a )``[ANS]` => `"[ANS] FORTH"`

  duplicate the cell on top of the stack - so the two topmost cells have the same value (they are equal w.r.t `=` ) , see `DROP` for the inverse

  primitive code = [p4_dup]

`ELSE``( -- )``[HIDDEN]` => `"[ANS] FORTH"`

  will compile an `((ELSE))` `BRANCH` that performs an unconditional jump to the next `THEN` - and it resolves an `IF` for the non-true case

  compiling word = [p4_else]

`EMIT``( char# -- )``[ANS]` => `"[ANS] FORTH"`

  print the char-value on stack to stdout

  primitive code = [p4_emit]

`ENVIRONMENT?``( name-ptr name-len -- 0 | ?? name-flag! )``[ANS]` => `"[ANS] FORTH"`

  check the environment for a property, usually a condition like questioning the existance of specified wordset, but it can also return some implementation properties like "WORDLISTS" (the length of the search-order) or "#LOCALS" (the maximum number of locals)

  Here it implements the environment queries as a `SEARCH-WORDLIST` in a user-visible vocabulary called `ENVIRONMENT`

        : ENVIRONMENT?
          ['] ENVIRONMENT >WORDLIST SEARCH-WORDLIST
          IF  EXECUTE TRUE ELSE  FALSE THEN ;

  primitive code = [p4_environment_Q_core]

`EVALUATE``( str-ptr str-len -- )``[ANS]` => `"[ANS] FORTH"`

  `INTERPRET` the given string, `SOURCE` id is -1 during that time.

  primitive code = [p4_evaluate]

`EXECUTE``( some-xt* -- ??? )``[ANS]` => `"[ANS] FORTH"`

  run the execution-token on stack - this will usually trap if it was null for some reason, see `>EXECUTE`

        simulate:
         : EXECUTE >R EXIT ;

  primitive code = [p4_execute]

`EXIT``( -- )``[ANS] [EXIT]` => `"[ANS] FORTH"`

  will unnest the current colon-word so it will actually return the word calling it. This can be found in the middle of a colon-sequence between `:` and `;`

  compiling word = [p4_exit]

`FILL``( mem-ptr mem-len char# -- )``[ANS]` => `"[ANS] FORTH"`

  fill a memory area with the given char, does now simply call p4_memset()

  primitive code = [p4_fill]

`FIND``( name-bstr* -- name-bstr* 0 | name-xt* -1|1 )``[ANS]` => `"[ANS] FORTH"`

  looks into the current search-order and tries to find the name string as the name of a word. Returns its execution-token or the original-bstring if not found, along with a flag-like value that is zero if nothing could be found. Otherwise it will be 1 (a positive value) if the word had been immediate, -1 otherwise (a negative value).

  primitive code = [p4_find]

`FM/MOD``( n1,n1# n2# -- div-n1# mod-n1# )``[ANS]` => `"[ANS] FORTH"`

  divide the double-cell value n1 by n2 and return both (floored) quotient n and remainder m

  primitive code = [p4_f_m_slash_mod]

`HERE``( -- here* )``[ANS]` => `"[ANS] FORTH"`

  used with `WORD` and many compiling words

        simulate:   : HERE DP @ ;

  primitive code = [p4_here]

`HOLD``( char# -- )``[ANS]` => `"[ANS] FORTH"`

  the old-style forth-formatting system -- this word adds a char to the picutred output string.

  primitive code = [p4_hold]

`I``( R: some,loop -- S: i# )``[ANS]` => `"[ANS] FORTH"`

  returns the index-value of the innermost `DO` .. `LOOP`

  compiling word = [p4_i]

`IF``( value -- )``[ANS]` => `"[ANS] FORTH"`

  checks the value on the stack (at run-time, not compile-time) and if true executes the code-piece between `IF` and the next `ELSE` or `THEN` . Otherwise it has compiled a branch over to be executed if the value on stack had been null at run-time.

  compiling word = [p4_if]

`IMMEDIATE``( -- )``[ANS]` => `"[ANS] FORTH"`

  make the `LATEST` word immediate, see also `CREATE`

  primitive code = [p4_immediate]

`INVERT``( value# -- value#' )``[ANS]` => `"[ANS] FORTH"`

  make a bitwise negation of the value on stack. see also `NEGATE`

  primitive code = [p4_invert]

`J``( R: some,loop -- S: j# )``[ANS]` => `"[ANS] FORTH"`

  get the current `DO` ... `LOOP` index-value being the not-innnermost. (the second-innermost...) see also for the other loop-index-values at `I` and `K`

  compiling word = [p4_j]

`KEY``( -- char# )``[ANS]` => `"[ANS] FORTH"`

  return a single character from the keyboard - the key is not echoed.

  primitive code = [p4_key]

`LEAVE``( R: some,loop -- R: some,loop )``[ANS]` => `"[ANS] FORTH"`

  quit the innermost `DO` .. `LOOP` - it does even clean the return-stack and branches to the place directly after the next `LOOP`

  compiling word = [p4_leave]

`LITERAL``( C: value -- S: value )``[ANS]` => `"[ANS] FORTH"`

  if compiling this will take the value from the compiling-stack and puts in dictionary so that it will pop up again at the run-time of the word currently in creation. This word is used in compiling words but may also be useful in making a hard-constant value in some code-piece like this:

        : DCELLS [ 2 CELLS ] LITERAL * ; ( will save a multiplication at runtime)

  (in most configurations this word is statesmart and it will do nothing in interpret-mode. See `LITERAL,` for a non-immediate variant)

  compiling word = [p4_literal]

`LOOP``( R: some,loop -- )``[ANS] [REPEAT]` => `"[ANS] FORTH"`

  resolves a previous `DO` thereby compiling `((LOOP))` which does increment/decrement the index-value and branch back if the end-value of the loop has not been reached.

  compiling word = [p4_loop]

`LSHIFT``( value# shift-count -- value#' )``[ANS]` => `"[ANS] FORTH"`

  does a bitwise left-shift on value

  primitive code = [p4_l_shift]

`M*``( a# b# -- a,a#' )``[ANS]` => `"[ANS] FORTH"`

  multiply and return a double-cell result

  primitive code = [p4_m_star]

`MAX``( a# b# -- a#|b# | a* b* -- a*|b* | a b -- a|b [??] )``[ANS]` => `"[ANS] FORTH"`

  return the maximum of a and b

  primitive code = [p4_max]

`MIN``( a# b# -- a#|b# | a* b* -- a*|b* | a b -- a|b [??] )``[ANS]` => `"[ANS] FORTH"`

  return the minimum of a and b

  primitive code = [p4_min]

`MOD``( a# b# -- mod-a# | a b# -- mod-a# [??] )``[ANS]` => `"[ANS] FORTH"`

  return the module of "a mod b"

  primitive code = [p4_mod]

`MOVE``( from-ptr to-ptr move-len -- )``[ANS]` => `"[ANS] FORTH"`

  p4_memcpy an area

  primitive code = [p4_move]

`NEGATE``( value# -- value#' )``[ANS]` => `"[ANS] FORTH"`

  return the arithmetic negative of the (signed) cell

        simulate:   : NEGATE -1 * ;

  primitive code = [p4_negate]

`OR``( a b# -- a' | a# b -- b' | a b -- a' [??] )``[ANS]` => `"[ANS] FORTH"`

  return the bitwise OR of a and b - unlike `AND` this is usually safe to use on logical values

  primitive code = [p4_or]

`OVER``( a b -- a b a )``[ANS]` => `"[ANS] FORTH"`

  get the value from under the top of stack. The inverse operation would be `TUCK`

  primitive code = [p4_over]

`POSTPONE``( [word] -- )``[ANS]` => `"[ANS] FORTH"`

  will compile the following word at the run-time of the current-word which is a compiling-word. The point is that `POSTPONE` takes care of the fact that word may be an IMMEDIATE-word that flags for a compiling word, so it must be executed (and not pushed directly) to compile sth. later. Choose this word in favour of `COMPILE` (for non-immediate words) and `[COMPILE]` (for immediate words)

  compiling word = [p4_postpone]

`QUIT``( -- )``[EXIT]` => `"[ANS] FORTH"`

  this will throw and lead back to the outer-interpreter. traditionally, the outer-interpreter is called QUIT in forth itself where the first part of the QUIT-word had been to clean the stacks (and some other variables) and then turn to an endless loop containing `QUERY` and `EVALUATE` (otherwise known as `INTERPRET` ) - in pfe it is defined as a `THROW` ,

        : QUIT -56 THROW ;

  primitive code = [p4_quit]

`R>``( R: a -- a R: )``[ANS]` => `"[ANS] FORTH"`

  get back a value from the return-stack that had been saved there using `>R` . This is the traditional form of a local var space that could be accessed with `R@` later. If you need more local variables you should have a look at `LOCALS|` which does grab some space from the return-stack too, but names them the way you like.

  compiling word = [p4_r_from]

`R@``( R: a -- a R: a )``[ANS]` => `"[ANS] FORTH"`

  fetch the (upper-most) value from the return-stack that had been saved there using `>R` - This is the traditional form of a local var space. If you need more local variables you should have a look at `LOCALS|` , see also `>R` and `R>` . Without LOCALS-EXT there are useful words like `2R@` `R'@` `R"@` `R!`

  compiling word = [p4_r_fetch]

`RECURSE``( ? -- ? )``[ANS]` => `"[ANS] FORTH"`

  when creating a colon word the name of the currently-created word is smudged, so that you can redefine a previous word of the same name simply by using its name. Sometimes however one wants to recurse into the current definition instead of calling the older defintion. The `RECURSE` word does it exactly this.

          traditionally the following code had been in use:
          : GREAT-WORD [ UNSMUDGE ] DUP . 1- ?DUP IF GREAT-WORD THEN ;
          now use
          : GREAT-WORD DUP . 1- ?DUP IF RECURSE THEN ;

  immediate code = [p4_recurse]

`REPEAT``( -- )``[ANS] [REPEAT]` => `"[ANS] FORTH"`

  ends an unconditional loop, see `BEGIN`

  compiling word = [p4_repeat]

`ROT``( a b c -- b c a )``[ANS]` => `"[ANS] FORTH"`

  rotates the three uppermost values on the stack, the other direction would be with `-ROT` - please have a look at `LOCALS|` and `VAR` that can avoid its use.

  primitive code = [p4_rot]

`RSHIFT``( value# shift-count# -- value#' )``[ANS]` => `"[ANS] FORTH"`

  does a bitwise logical right-shift on value (ie. the value is considered to be unsigned)

  primitive code = [p4_r_shift]

`S"``( [string<">] -- string-ptr string-len)``[ANS]` => `"[ANS] FORTH"`

  if compiling then place the string into the currently compiled word and on execution the string pops up again as a double-cell value yielding the string's address and length. To be most portable this is the word to be best being used. Compare with `C"` and non-portable `"`

  compiling word = [p4_s_quote]

`S>D``( a# -- a,a#' | a -- a,a#' [??] )``[ANS]` => `"[ANS] FORTH"`

  signed extension of a single-cell value to a double-cell value

  primitive code = [p4_s_to_d]

`SIGN``( a# -- )``[ANS]` => `"[ANS] FORTH"`

  put the sign of the value into the hold-space, this is the forth-style output formatting, see `HOLD`

  primitive code = [p4_sign]

`SM/REM``( a,a# b# -- div-a# rem-a# )``[ANS]` => `"[ANS] FORTH"`

  see `/MOD` or `FM/MOD` or `UM/MOD` or `SM/REM`

  primitive code = [p4_s_m_slash_rem]

`SOURCE``( -- buffer* IN-offset# )``[ANS]` => `"[ANS] FORTH"`

  the current point of interpret can be gotten through SOURCE. The buffer may flag out TIB or BLK or a FILE and IN gives you the offset therein. Traditionally, if the current SOURCE buffer is used up, `REFILL` is called that asks for another input-line or input-block. This scheme would have made it impossible to stretch an [IF] ... [THEN] over different blocks, unless [IF] does call `REFILL`

  primitive code = [p4_source]

`SPACE``( -- )``[ANS]` => `"[ANS] FORTH"`

  print a single space to stdout, see `SPACES`

        simulate:    : SPACE  BL EMIT ;

  primitive code = [p4_space]

`SPACES``( space-count -- )``[ANS]` => `"[ANS] FORTH"`

  print n space to stdout, actually a loop over n calling `SPACE` , but the implemenation may take advantage of printing chunks of spaces to speed up the operation.

  primitive code = [p4_spaces]

`SWAP``( a b -- b a )``[ANS]` => `"[ANS] FORTH"`

  exchanges the value on top of the stack with the value beneath it

  primitive code = [p4_swap]

`THEN``( -- )``[ANS]` => `"[ANS] FORTH"`

  does resolve a branch coming from either `IF` or `ELSE`

  compiling word = [p4_then]

`TYPE``( string-ptr string-len -- )``[ANS]` => `"[ANS] FORTH"`

  prints the string-buffer to stdout, see `COUNT` and `EMIT`

  primitive code = [p4_type]

`U.``( value# -- | value -- [?] )``[ANS]` => `"[ANS] FORTH"`

  print unsigned number to stdout

  primitive code = [p4_u_dot]

`U<``( a b -- test-flag )``[ANS]` => `"[ANS] FORTH"`

  unsigned comparison, see `<`

  primitive code = [p4_u_less_than]

`UM*``( a# b# -- a,a#' )``[ANS]` => `"[ANS] FORTH"`

  unsigned multiply returning double-cell value

  primitive code = [p4_u_m_star]

`UM/MOD``( a,a# b# -- div-a#' mod-a#' )``[ANS]` => `"[ANS] FORTH"`

  see `/MOD` and `SM/REM`

  primitive code = [p4_u_m_slash_mod]

`UNLOOP``( R: some,loop -- )``[ANS]` => `"[ANS] FORTH"`

  drop the `DO` .. `LOOP` runtime variables from the return-stack, usually used just in before an `EXIT` call. Using this multiple times can unnest multiple nested loops.

  compiling word = [p4_unloop]

`UNTIL``( test-flag -- )``[ANS] [REPEAT]` => `"[ANS] FORTH"`

  ends an control-loop, see `BEGIN` and compare with `WHILE`

  compiling word = [p4_until]

`WHILE``( test-flag -- )``[ANS]` => `"[ANS] FORTH"`

  middle part of a `BEGIN` .. `WHILE` .. `REPEAT` control-loop - if cond is true the code-piece up to `REPEAT` is executed which will then jump back to `BEGIN` - and if the cond is null then `WHILE` will branch to right after the `REPEAT` (compare with `UNTIL` that forms a `BEGIN` .. `UNTIL` loop)

  compiling word = [p4_while]

`WORD``( delimiter-char# -- here* )``[ANS]` => `"[ANS] FORTH"`

  read the next `SOURCE` section (thereby moving `>IN` ) up to the point reaching $delimiter-char - the text is placed at `HERE` - where you will find a counted string. You may want to use `PARSE` instead.

  primitive code = [p4_word]

`XOR``( a# b# -- a#' )``[ANS]` => `"[ANS] FORTH"`

  return the bitwise-or of the two arguments - it may be unsafe use it on logical values. beware.

  primitive code = [p4_xor]

`[``( -- )``[ANS]` => `"[ANS] FORTH"`

  leave compiling mode - often used inside of a colon-definition to make fetch some very constant value and place it into the currently compiled colon-defintion with => , or `LITERAL` - the corresponding unleave word is `]`

  immediate code = [p4_left_bracket]

`[']``( [name] -- name-xt* )``[ANS]` => `"[ANS] FORTH"`

  will place the execution token of the following word into the dictionary. See `'` for non-compiling variant.

  compiling word = [p4_bracket_tick]

`[CHAR]``( [word] -- char# )``[ANS]` => `"[ANS] FORTH"`

  in compile-mode, get the (ascii-)value of the first charachter in the following word and compile it as a literal so that it will pop up on execution again. See `CHAR` and forth-83 `ASCII`

  compiling word = [p4_bracket_char]

`]``( -- )``[ANS]` => `"[ANS] FORTH"`

  enter compiling mode - often used inside of a colon-definition to end a previous `[` - you may find a => , or `LITERAL` nearby in example texts.

  primitive code = [p4_right_bracket]

`.(``( [message<closeparen>] -- )``[ANS]` => `"[ANS] FORTH"`

  print the message to the screen while reading a file. This works too while compiling, so you can whatch the interpretation/compilation to go on. Some Forth-implementations won't even accept a => ." message" outside compile-mode while the (current) pfe does.

  immediate code = [p4_dot_paren]

`.R``( value# precision# -- | value precision# -- [??] )``[ANS]` => `"[ANS] FORTH"`

  print with precision - that is to fill a field of the give prec-with with right-aligned number from the converted value

  primitive code = [p4_dot_r]

`0<>``( 0 -- 0 | value! -- value-flag! | value -- value-flag )``[ANS]` => `"[ANS] FORTH"`

  returns a logical-value saying if the value was not-zero. This is most useful in turning a numerical value into a boolean value that can be fed into bitwise words like `AND` and `XOR` - a simple `IF` or `WHILE` doesn't need it actually.

  primitive code = [p4_zero_not_equals]

`0>``( 0 -- 0 | value! -- value-flag! | value -- value-flag )``[ANS]` => `"[ANS] FORTH"`

  return value greater than zero

        simulate:    : 0> 0 > ;

  primitive code = [p4_zero_greater]

`2>R``( a,a -- R: a,a )``[ANS]` => `"[ANS] FORTH"`

  save a double-cell value onto the return-stack, see `>R`

  compiling word = [p4_two_to_r]

`2R>``( R: a,a -- a,a R: )``[ANS]` => `"[ANS] FORTH"`

  pop back a double-cell value from the return-stack, see `R>` and the earlier used `2>R`

  compiling word = [p4_two_r_from]

`2R@``( R: a,a -- a,a R: a,a )``[ANS]` => `"[ANS] FORTH"`

  fetch a double-cell value from the return-stack, that had been previously been put there with `2>R` - see `R@` for single value. This can partly be a two-cell `LOCALS|` value, without LOCALS-EXT there are alos other useful words like `2R!` `R'@` `R"@`

  compiling word = [p4_two_r_fetch]

`<>``( a b -- a-flag )``[ANS]` => `"[ANS] FORTH"`

  return true if a and b are not equal, see `=`

  primitive code = [p4_not_equals]

`?DO``( end# start# | end* start* -- R: some,loop )``[ANS]` => `"[ANS] FORTH"`

  start a control-loop just like `DO` - but don't execute atleast once. Instead jump over the code-piece if the loop's variables are not in a range to allow any loop.

  compiling word = [p4_Q_do]

`AGAIN``( -- )``[ANS] [REPEAT]` => `"[ANS] FORTH"`

  ends an infinite loop, see `BEGIN` and compare with `WHILE`

  compiling word = [p4_again]

`C"``( [string<">] -- string-bstr* )``[ANS]` => `"[ANS] FORTH"`

  in compiling mode place the following string in the current word and return the address of the counted string on execution. (in exec-mode use a `POCKET` and leave the bstring-address of it), see `S"` string" and the non-portable `"` string"

  compiling word = [p4_c_quote]

`CASE``( value -- value )``[ANS]` => `"[ANS] FORTH"`

  start a CASE construct that ends at `ENDCASE` and compares the value on stack at each `OF` place

  compiling word = [p4_case]

`COMPILE,``( some-xt* -- )``[ANS]` => `"[ANS] FORTH"`

  place the execution-token on stack into the dictionary - in traditional forth this is not even the least different than a simple => , but in call-threaded code there's a big difference - so COMPILE, is the portable one. Unlike `COMPILE` , `[COMPILE]` and `POSTPONE` this word does not need the xt to have actually a name, see `:NONAME`

  primitive code = [p4_compile_comma]

`CONVERT``( a,a# string-bstr* -- a,a# a-len# )``[ANS] [OLD]` => `"[ANS] FORTH"`

  digit conversion, obsolete, superseded by `>NUMBER`

  primitive code = [p4_convert]

`ENDCASE``( value -- )``[ANS]` => `"[ANS] FORTH"`

  ends a `CASE` construct that may surround multiple sections of `OF` ... `ENDOF` code-portions. The `ENDCASE` has to resolve the branches that are necessary at each `ENDOF` to point to right after `ENDCASE`

  compiling word = [p4_endcase]

`ENDOF``( -- )``[ANS]` => `"[ANS] FORTH"`

  resolve the branch need at the previous `OF` to mark a code-piece and leave with an unconditional branch at the next `ENDCASE` (opened by `CASE` )

  compiling word = [p4_endof]

`ERASE``( buffer-ptr buffer-len -- )``[ANS]` => `"[ANS] FORTH"`

  fill an area will zeros.

        2000 CREATE DUP ALLOT ERASE

  primitive code = [p4_erase]

`EXPECT``( str-ptr str-len -- )``[ANS] [OLD]` => `"[ANS] FORTH"`

  input handling, see `WORD` and `PARSE` and `QUERY` the input string is placed at str-adr and its length

        in => SPAN - this word is superceded by => ACCEPT

  primitive code = [p4_expect]

`HEX``( -- )``[ANS]` => `"[ANS] FORTH"`

  set the input/output `BASE` to hexadecimal

        simulate:        : HEX 16 BASE ! ;

  primitive code = [p4_hex]

`NIP``( a b -- b )``[ANS]` => `"[ANS] FORTH"`

  drop the value under the top of stack, inverse of `TUCK`

        simulate:        : NIP SWAP DROP ;

  primitive code = [p4_nip]

`OF``( value test -- value )``[ANS]` => `"[ANS] FORTH"`

  compare the case-value placed lately with the comp-value being available since `CASE` - if they are equal run the following code-portion up to `ENDOF` after which the case-construct ends at the next `ENDCASE`

  compiling word = [p4_of]

`PAD``( -- pad* )``[ANS]` => `"[ANS] FORTH"`

  transient buffer region

  primitive code = [p4_pad]

`PARSE``( delim-char# -- buffer-ptr buffer-len )``[ANS]` => `"[ANS] FORTH"`

  parse a piece of input (not much unlike WORD) and place it into the given buffer. The difference with word is also that `WORD` would first skip any delim-char while `PARSE` does not and thus may yield that one. In a newer version, `PARSE` will not copy but just return the word-span being seen in the input-buffer - therefore a transient space.

  primitive code = [p4_parse]

`PICK``( value ...[n-1] n -- value ...[n-1] value )``[ANS]` => `"[ANS] FORTH"`

  pick the nth value from under the top of stack and push it note that

          0 PICK -> DUP         1 PICK -> OVER

  primitive code = [p4_pick]

`QUERY``( -- )``` => `"[ANS] FORTH"`

  source input: read from terminal using `_accept_` with the returned string to show up in `TIB` of `/TIB` size.

  primitive code = [p4_query]

`REFILL``( -- refill-flag )``[ANS]` => `"[ANS] FORTH"`

  try to get a new input line from the `SOURCE` and set `>IN` accordingly. Return a flag if sucessful, which is always true if the current input comes from a terminal and which is always false if the current input comes from `EVALUATE` - and may be either if the input comes from a file

  primitive code = [p4_refill]

`RESTORE-INPUT``( input...[input-len] input-len -- )``[ANS]` => `"[ANS] FORTH"`

  inverse of `SAVE-INPUT`

  primitive code = [p4_restore_input]

`ROLL``( value ...[n-1] n -- ...[n-1] value )``[ANS]` => `"[ANS] FORTH"`

  the extended form of `ROT`

           2 ROLL -> ROT

  primitive code = [p4_roll]

`SAVE-INPUT``( -- input...[input-len] input-len )``[ANS]` => `"[ANS] FORTH"`

  fetch the current state of the input-channel which may be restored with `RESTORE-INPUT` later

  primitive code = [p4_save_input]

`TO``( value [name] -- )``[ANS]` => `"[ANS] FORTH"`

  set the parameter field of name to the value, this is used to change the value of a `VALUE` and it can be also used to change the value of `LOCALS|`

  compiling word = [p4_to]

`TUCK``( a b -- b a b )``[ANS]` => `"[ANS] FORTH"`

  shove the top-value under the value beneath. See `OVER` and `NIP`

        simulate:    : TUCK  SWAP OVER ;

  primitive code = [p4_tuck]

`U.R``( value# precision# -- )``[ANS]` => `"[ANS] FORTH"`

  print right-aligned in a prec-field, treat value to be unsigned as opposed to => .R

  primitive code = [p4_u_dot_r]

`U>``( a b -- a-flag )``[ANS]` => `"[ANS] FORTH"`

  unsigned comparison of a and b, see `>`

  primitive code = [p4_u_greater_than]

`UNUSED``( -- unused-len )``[ANS]` => `"[ANS] FORTH"`

  return the number of cells that are left to be used above `HERE`

  primitive code = [p4_unused]

`WITHIN``( a# b# c# -- a-flag | a* b* c* -- a-flag )``[ANS]` => `"[ANS] FORTH"`

  a widely used word, returns ( b <= a && a < c ) so that is very useful to check an index a of an array to be within range b to c

  primitive code = [p4_within]

`[COMPILE]``( [word] -- )``[ANS]` => `"[ANS] FORTH"`

  while compiling the next word will be place in the currently defined word no matter if that word is immediate (like `IF` ) - compare with `COMPILE` and `POSTPONE`

  immediate code = [p4_bracket_compile]

`\``( [comment<eol>] -- )``[ANS]` => `"[ANS] FORTH"`

  eat everything up to the next end-of-line so that it is getting ignored by the interpreter.

  immediate code = [p4_backslash]

`PARSE-WORD``( "chars" -- buffer-ptr buffer-len )``[ANS]` => `"[ANS] FORTH"`

  the ANS'94 standard describes this word in a comment under `PARSE`, section A.6.2.2008 - quote:

  Skip leading spaces and parse name delimited by a space. c-addr is the address within the input buffer and u is the length of the selected string. If the parse area is empty, the resulting string has a zero length.

  If both `PARSE` and `PARSE-WORD` are present, the need for `WORD` is largely eliminated. Note that Forth200x calls it `PARSE-NAME` and clarifies that non-empty whitespace-only input is returned as a zero length string as well.

  primitive code = [p4_parse_word]

`PARSE-NAME``( "chars" -- buffer-ptr buffer-len )``[Forth200x]` => `"[ANS] FORTH"`

  This word is identical with the PFE implementation `PARSE-WORD`

  The only difference between the 1994 ANS-Forth PARSE-WORD and the 2005 Forth200x PARSE-NAME is in the explicit condition of whitespace-only - while 1994 reads "If the parse area is empty, the resulting string has a zero length." you will find that the 2005 version says "If the parse area is empty or contains only white space, the resulting string has length zero."

  primitive code = [p4_parse_word]

`CFA'``( 'name' -- name-xt* )``[FTH]` => `"[ANS] FORTH"`

  return the execution token of the following name. This word is _not_ immediate and may not do what you expect in compile-mode. See `[']` and `'>` - note that in FIG-forth the word `'` had returned the PFA (not the CFA) and therefore this word was introduced being the `SYNONYM` of the ans-like word `'`

  primitive code = [p4_tick]

`STACK-CELLS``` => `"ENVIRONMENT"`

  (no description)

  primitive code = [p__stack_cells]

`RETURN-STACK-CELLS``` => `"ENVIRONMENT"`

  (no description)

  primitive code = [p__return_stack_cells]

## CORE-Misc

> Compatibility words

`0<=``( a -- flag )``` => `"FORTH"`

        simulate    : 0<= 0> 0= ;

  primitive code = [p4_zero_less_equal]

`0>=``( a -- flag )``` => `"FORTH"`

        simulate    : 0>= 0< 0= ;

  primitive code = [p4_zero_greater_equal]

`<=``( a b -- flag )``` => `"FORTH"`

        simulate    : <= > 0= ;

  primitive code = [p4_less_equal]

`>=``( a b -- flag )``` => `"FORTH"`

        simulate    : >= < 0= ;

  primitive code = [p4_greater_equal]

`U<=``( a b -- flag )``` => `"FORTH"`

        simulate    : U<= U> 0= ;

  primitive code = [p4_u_less_equal]

`U>=``( a b -- flag )``` => `"FORTH"`

        simulate    : U>= U< 0= ;

  primitive code = [p4_u_greater_equal]

`UMIN``( a b -- min )``` => `"FORTH"`

  see `MIN` , `MAX` and `UMAX`

  primitive code = [p4_u_min]

`UMAX``( a b -- max )``` => `"FORTH"`

  see `MAX`

  primitive code = [p4_u_max]

`.VERSION``( -- )``` => `"FORTH"`

  show the version of the current PFE system

        : .VERSION [ ENVIRONMENT ] FORTH-NAME TYPE FORTH-VERSION TYPE ;

  primitive code = [p4_dot_version]

`.CVERSION``( -- )``` => `"FORTH"`

  show the compile date of the current PFE system

        : .CVERSION [ ENVIRONMENT ] FORTH-NAME TYPE FORTH-DATE TYPE ;

  primitive code = [p4_dot_date]

`LICENSE``( -- )``` => `"FORTH"`

  show a lisence info - the basic PFE system is licensed under the terms of the LGPL (Lesser GNU Public License) - binary modules loaded into the system and hooking into the system may carry another `LICENSE`

        : LICENSE [ ENVIRONMENT ] FORTH-LICENSE TYPE ;

  primitive code = [p4_license]

`WARRANTY``( -- )``` => `"FORTH"`

  show a warranty info - the basic PFE system is licensed under the terms of the LGPL (Lesser GNU Public License) - which exludes almost any liabilities whatsoever - however loadable binary modules may hook into the system and their functionality may have different WARRANTY infos.

  primitive code = [p4_warranty]

`STRING,``( str len -- )``` => `"FORTH"`

  Store a string in data space as a counted string.

        : STRING, HERE  OVER 1+  ALLOT  PLACE ;

  primitive code = [p4_string_comma]

`PARSE,``( "chars<">" -- )``` => `"FORTH"`

  Store a char-delimited string in data space as a counted string. As seen in Bawd's

        : ," [CHAR] " PARSE  STRING, ; IMMEDIATE

  this implementation is much different from Bawd's

        : PARSE, PARSE STRING, ;

  primitive code = [p4_parse_comma]

`PARSE,"``` => `"FORTH"`

  (no description)

  immediate code = [p4_parse_comma_quote]

`DEFINED``( "name" -- flag )``` => `"FORTH"`

  Search the dictionary for _name_. If _name_ is found, return TRUE; otherwise return FALSE. Immediate for use in definitions.

  This word will actually return what `FIND` returns (the NFA). does check for the word using find (so it does not throw like `'` ) and puts it on stack. As it is immediate it does work in compile-mode too, so it places its argument in the cs-stack then. This is most useful with a directly following `[IF]` clause, so that sth. like an `[IFDEF] word` can be simulated through `[DEFINED] word [IF]`

        : DEFINED BL WORD COUNT (FIND-NFA) ;

  primitive code = [p4_defined]

`[DEFINED]``( "name" -- flag )``` => `"FORTH"`

  Search the dictionary for _name_. If _name_ is found, return TRUE; otherwise return FALSE. Immediate for use in definitions.

  [DEFINED] word ( -- nfa|0 ) immediate does check for the word using find (so it does not throw like `'` ) and puts it on stack. As it is immediate it does work in compile-mode too, so it places its argument in the cs-stack then. This is most useful with a directly following `[IF]` clause, so that sth. like an `[IFDEF] word` can be simulated through `[DEFINED] word [IF]`

        : [DEFINED] BL WORD FIND NIP ; IMMEDIATE

  immediate code = [p4_defined]

`[UNDEFINED]``( "name" -- flag )``` => `"FORTH"`

  Search the dictionary for _name_. If _name_ is found, return FALSE; otherwise return TRUE. Immediate for use in definitions.

  see `[DEFINED]`

  immediate code = [p4_undefined]

`(MARKER)``( str-ptr str-len -- )``` => `"FORTH"`

  create a named marker that you can use to `FORGET` , running the created word will reset the dict/order variables to the state at the creation of this name.

        : (MARKER) (CREATE) HERE ,
                GET-ORDER DUP , 0 DO ?DUP IF , THEN LOOP 0 ,
                ...
          DOES> DUP @ (FORGET)
                ...
        ;

  primitive code = [p4_paren_marker]

`ANEW``( 'name' -- )``` => `"FORTH"`

  creates a `MARKER` if it doesn't exist, or forgets everything after it if it does. (it just gets executed).

  Note: in PFE the `ANEW` will always work on the `ENVIRONMENT-WORDLIST` which has a reason: it is never quite sure whether the same `DEFINITIONS` wordlist is in the search `ORDER` that the original `ANEW` `MARKER` was defined in. Therefore, `ANEW` would be only safe on systems that do always stick to `FORTH` `DEFINITIONS`. Instead we will `CREATE` the `ANEW` `MARKER` in the `ENVIRONMENT` and use a simple `SEARCH-WORDLIST` on the `ENVIRONMENT-WORDLIST` upon re-run.

        \ old
        : ANEW BL WORD   DUP FIND NIP IF EXECUTE THEN   (MARKER) ;
        \ new
        : ANEW
          PARSE-WORD  2DUP ENVIRONMENT-WORDLIST SEARCH-WORDLIST IF  EXECUTE  THEN
          GET-CURRENT >R ENVIRONMENT-WORDLIST SET-CURRENT  (MARKER)  R> SET-CURRENT ;

  primitive code = [p4_anew]

## Debugger

> words

`DEBUG``( "word" -- )``[FTH]` => `"FORTH"`

  this word will place an debug-runtime into the `CFA` of the following word. If the word gets executed later, the user will be prompted and can decide to single-step the given word. The debug-stepper is interactive and should be self-explanatory. (use `NO-DEBUG` to turn it off again)

  primitive code = [p4_debug]

`NO-DEBUG``( "word" -- )``[FTH]` => `"FORTH"`

  the inverse of " `DEBUG` word "

  primitive code = [p4_no_debug]

`(SEE)``` => `"FORTH"`

  (no description)

  primitive code = [p4_paren_see]

`ADDR>NAME``( word-addr* -- word-nfa*!' | 0 )``[FTH]` => `"FORTH"`

  search the next corresponding namefield that address is next too. If it is not in the base-dictionary, then just return 0 as not-found.

  primitive code = [p4_addr_to_name]

`COME_BACK``( -- )``[FTH]` => `"FORTH"`

  show the return stack before last exception along with the best names as given by `ADDR>NAME`

  primitive code = [p4_come_back]

## Dynamic-Loading

> of code modules

`(LOADM)``` => `"FORTH"`

  (no description)

  primitive code = [p4_paren_loadm]

`LOADM``( "filename" -- )``[FTH]` => `"FORTH"`

  dlmap the shared object (or share an already mapped object) and run the per-thread initialization code. This is the user-convenient function, otherwise use `(LOADM)`

        simulate:
          : LOADM  BL WORD
            ((IS_MODULE_LOADED)) IF EXIT THEN
            HERE (LOADM)  0= IF ." -- load failed: " HERE COUNT TYPE CR THEN ;

  primitive code = [p4_loadm]

`LOCAL-DLSYM``( [symbol] -- symbol-addr )``[FTH] [EXEC]` => `"FORTH"`

  lookup the symbol that follows and leave the address (or null)

  immediate code = [p4_local_dlsym]

`LOCAL-DLCALL``` => `"FORTH"`

  (no description)

  immediate code = [p4_local_dlcall]

`CALL-C``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_call_c]

`USELIBRARY``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_uselibrary]

`lt_dlinit``( -- dlinit-ior# )``[FTH]` => `"EXTENSIONS"`

  initialiize library, usually open the program itself so that its handles can be found under "0"

  primitive code = [p4_lt_dlinit]

`lt_dlopenext``( module-ptr module-len -- module-dl-handle*! | 0 )``[FTH]` => `"EXTENSIONS"`

  walk the searchpath for dlopen and try to open a binary module under the given name with the usual file extension for the current system.

  primitive code = [p4_lt_dlopenext]

`lt_dlsym``( symbol-ptr symbol-len module-dl-handle* -- symbol*! | 0 )``[FTH]` => `"EXTENSIONS"`

  try to find the name in the binary module denoted by its handle .. if handle is null, use the main body of the program

  primitive code = [p4_lt_dlsym]

`lt_dlclose``( module-dl-handle* -- module-ior# )``[FTH]` => `"EXTENSIONS"`

  close handle that was returned by `lt_dlopenext`

  primitive code = [p4_lt_dlcose]

`lt_dlerror``( -- dlerror-zstr* )``` => `"EXTENSIONS"`

  returns string describing the last dlerror as for `lt_dlopenext` and `lt_dlsym`

  primitive code = [p4_lt_dlerror]

## Double

> number + extensions

`2LITERAL``( x1 x2 -- )``immediate` => `"[ANS] FORTH"`

  compile a double-cell number to the current definition. When run, the doubele-cell is left on the stack for execution.

          ( -- x1 x2 )

  (in most configurations this word is statesmart and it will do nothing in interpret-mode. See `2LITERAL,` for a non-immediate variant)

  compiling word = [p4_two_literal]

`D+``( d1.ud1 d2.ud2 -- d3.ud3 )``` => `"[ANS] FORTH"`

  the double-cell sum operation ( `+` )

  primitive code = [p4_d_plus]

`D-``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_d_minus]

`D.``( d1.d1 -- )``` => `"[ANS] FORTH"`

  freefield output for a double-cell number ( => . )

  primitive code = [p4_d_dot]

`D.R``( d1.d1 n -- )``` => `"[ANS] FORTH"`

  aligned output for a double-cell number ( => .R )

  primitive code = [p4_d_dot_r]

`D0<``( d1.d1 -- flag )``` => `"[ANS] FORTH"`

  the double-cell less-than-zero operation ( `0<` )

  primitive code = [p4_d_zero_less]

`D0=``( d1.d1 -- flag )``` => `"[ANS] FORTH"`

  the double-cell equal-to-zero operation ( `0=` )

  primitive code = [p4_d_zero_equals]

`D2*``( d1.d1 -- d1.d1' )``` => `"[ANS] FORTH"`

  the double-cell arithmetic shiftleft-by-1 operation ( `2*` )

  primitive code = [p4_d_two_star]

`D2/``( d1.d1 -- d1.d1' )``` => `"[ANS] FORTH"`

  the double-cell arithmetic shiftright-by-1 operation ( `2/` )

  primitive code = [p4_d_two_slash]

`D<``( d1.d1 d2.d2 -- flag )``` => `"[ANS] FORTH"`

  the double-cell is-less operation ( `<` )

  primitive code = [p4_d_less]

`D=``( d1.d1 d2.d2 -- flag )``` => `"[ANS] FORTH"`

  the double-cell is-equal operation ( `=` )

  primitive code = [p4_d_equals]

`D>S``( d.d -- n )``` => `"[ANS] FORTH"`

  result is the numeric equivalent of d. If the double number was greater than what could fit into a single cell number, the modulo cellsize will be left since the higher-significant bits are just `DROP`ed

  primitive code = [p4_d_to_s]

`DABS``( d1.d1 -- d1.d1' )``` => `"[ANS] FORTH"`

  the double-cell abs operation ( `ABS` )

  primitive code = [p4_d_abs]

`DMAX``( d1.d1 d2.d2 -- d1.d1|d2.d2 )``` => `"[ANS] FORTH"`

  the double-cell max operation ( `MAX` )

  primitive code = [p4_d_max]

`DMIN``( d1.d1 d2.d2 -- d1.d1|d2.d2 )``` => `"[ANS] FORTH"`

  the double-cell max operation ( `MIN` )

  primitive code = [p4_d_min]

`DNEGATE``( d1.d1 -- d1.d1' )``` => `"[ANS] FORTH"`

  the double-cell arithmetic negate operation ( `NEGATE` )

  primitive code = [p4_d_negate]

`M*/``( d1.d1 n1 +n2 -- d2.d2 )``` => `"[ANS] FORTH"`

  the double-cell multiply-divide operation using a triple-cell intermediate result for `*` ( `*\/` )

  primitive code = [p4_m_star_slash]

`M+``( d1.d1 n1 -- d2.d2 )``` => `"[ANS] FORTH"`

  the double-cell mixed-operand sum operation ( `+` / `D+` )

  primitive code = [p4_m_plus]

## DOUBLE-Misc

> Compatibility words

`2ROT``( d1,d1 d2,d2 d3,d3 -- d2,d2 d3,d3 d1,d1 )``` => `[FORTH]`

  the double-cell `ROT` operation. actively moves six cells, i.e.

          ( x1 x2 x3 x4 x5 x6 -- x3 x4 x5 x6 x1 x2 )

  primitive code = [p4_two_rot]

`DU<``( d1,d1 d2,d2 -- flag )``` => `[FORTH]`

  the double-cell unsigned-is-less operation ( `U<` )

  primitive code = [p4_d_u_less]

`LITERAL,``( value -- )``` => `[FORTH]`

  take the value from stack (or cs-stack) and compile a runtime-code and the value as for `LITERAL` ... this word is never state-smart, it is not immediate, and has therefore no complications with `POSTPONE` (compare also with `COMPILE,` to make a call-stub with an exectoken)

  primitive code = [p4_literal_comma]

`2LITERAL,``( x1,x2 -- )``` => `[FORTH]`

  take the double-value from stack (or cs-stack) and compile a runtime-code and the value as for `2LITERAL` ... this word is never state-smart, it is not immediate, and has therefore no complications with `POSTPONE` (compare also with `COMPILE,` to make a call-stub with an exectoken)

  primitive code = [p4_two_literal_comma]

`DCELLS``( x -- x' )``` => `[FORTH]`

  computes the number of address units for the specified number of double-cells

        : DCELLS CELLS 2* ;

  primitive code = [p4_dcells]

`DLSHIFT``( x1,x2 y -- z1,z2 )``` => `[FORTH]`

  shift-left a double-cell value. The shift-count is given as a single-cell.

  primitive code = [p4_d_shiftleft]

`DRSHIFT``( x1,x2 y -- z1,z2 )``` => `[FORTH]`

  shift-right a double-cell value. The shift-count is given as a single-cell. This is an arithmetic shift as for a signed double-cell value.

  primitive code = [p4_d_shiftright]

## Dynamic-Strings

> extension

`EMPTY$``( $: -- empty$ )``` => `[FORTH]`

  Push the MSA of a fixed, external representation of the empty string onto the string stack. "empty-string"

  primitive code = [p4_empty_str]

`\n$``( $: -- newline$ )``` => `[FORTH]`

  Push the MSA of a fixed, external string whose body is the Unix newline character onto the string stack. "newline-string"

  primitive code = [p4_newline_str]

`(M!)``` => `[FORTH]`

  (no description)

  primitive code = [p4_parens_m_store]

`PARSE>S``( [ccc<char>] char -- addr len )``` => `[FORTH]`

  Parse the input stream up to the first occurrence of char, which is parsed away. If executing in compilation mode, append run-time semantics to the current definition that leaves the ANS Forth string representation on the stack. In interpretation mode, leave the ANS Forth string representation for a stored copy, which may be transient in the style of `S`". In either mode, the format of the stored string is implementation dependent. "parse-to-s"

  NOTE: The interpreted copy is a nontransient in this implementation, and both copies are mstrings.

  primitive code = [p4_parse_to_s]

`S```( [ccc<`>] -- addr len )``` => `[FORTH]`

  An immediate version of parse>s where the delimiter is `. In particular, the stored string in interpret mode is not transient. "s-back-tick"

  compiling word = [p4_s_back_tick]

`M,S``( addr len -- addr' len )``` => `[FORTH]`

  ALLOT room and store the ANS Forth string into aligned data space as an mstring, leaving data space zero-filled to alignment; and leave the length and new body address. It is assumed that len is unsigned. An error is thrown if len is larger than the system parameter `MAX_DATA_STR`. "m-comma-s"

  NOTE: `MAX_DATA_STR` is returned by

          S" /SCOPY" ENVIRONMENT?

  NOTE: `M,S` differs from `STRING,` in Wil Baden's Tool Belt in that it stores an aligned, measured string with zero-filled alignment instead of a counted string, and it leaves the ANS Forth string representation of the stored string.

  primitive code = [p4_m_comma_s]

`MCOUNT@``( msa -- count )``` => `[FORTH]`

  Fetch the count of the mstring at msa. "m-count-fetch"

  primitive code = [p4_m_count_fetch]

`MCOUNT!``( count msa -- )``` => `[FORTH]`

  Store the count in the measured string count field at msa, without checking that it fits. "m-count-store"

  primitive code = [p4_m_count_store]

`MCOUNT``( msa -- body.addr count )``` => `[FORTH]`

  Convert the mstring MSA to its ANS Forth string representation. "m-count"

  primitive code = [p4_m_count]

`-MCOUNT``( addr len -- msa )``` => `[FORTH]`

  Convert the ANS Forth representation of an mstring to its MSA. "minus-m-count"

  primitive code = [p4_minus_m_count]

`($:``` => `[FORTH]`

  (no description)

  immediate code = [p4_paren]

`0STRINGS``( -- )``` => `[FORTH]`

  Set all string variables holding bound string values in string space to the empty string, and clear string space, including the string buffer, string stack, and string stack frames. "zero-strings"

  NOTE: If used for under the hood development, this word must be executed only when string space is in a valid state.

  primitive code = [p4_zero_strings]

`$GARBAGE?``( -- flag )``` => `[FORTH]`

  Leave true if there is garbage in the current string space. Not normally used, since garbage collection is transparent. "string-garbage-question"

  primitive code = [p4_str_garbage_Q]

`$GC-OFF``( -- )``` => `[FORTH]`

  Disable garbage collection in the current string space. An error will be thrown if garbage collection is attempted. "string-g-c-off"

  primitive code = [p4_str_gc_off]

`$GC-ON``( -- )``` => `[FORTH]`

  Enable garbage collection in the current string space. This is the default. "string-g-c-on"

  primitive code = [p4_str_gc_on]

`$GC-LOCK@``( -- flag )``` => `[FORTH]`

  Fetch the dstring garbage collection "off" state. Intended for saving the off state for later restoration after a usage of `$GC-ON` or `$GC-OFF`. "string-g-c-lock-fetch"

  primitive code = [p4_str_gc_lock_fetch]

`$GC-LOCK!``( flag -- )``` => `[FORTH]`

  Set the dstring garbage collection "off" state according to flag. Intended for restoring the off state previously fetched by `$GC-LOCK@`. "string-g-c-lock-fetch"

  primitive code = [p4_str_gc_lock_store]

`$UNUSED``( -- u )``` => `[FORTH]`

  Leave the number of bytes available for dynamic strings and string stack entries in the string buffer. "string-unused"

  primitive code = [p4_str_unused]

`COLLECT-$GARBAGE``( -- collected-flag )``` => `[FORTH]`

  If string space is not marked as containing garbage, return false. If there is garbage, throw an error when garbage collection is disabled. Otherwise remove the garbage and return true. Garbage collection is "transparent", so the user would not normally use this word. "collect-string-garbage"

  primitive code = [p4_collect_str_garbage]

`MAKE-$SPACE``( size #frames -- addr )``` => `[FORTH]`

  Allocate and initialize a string space with size bytes available for the string buffer including the string stack, and with a string frame stack for frame description entries holding up to #frames. The size is rounded up to cell alignment, and the buffer begins and ends with cell alignment. Return addr, the address of the string space. The standard word `FREE` with addr as input can be used to release the space. "make-string-space"

  primitive code = [p4_make_str_space]

`/$BUF``( -- u )``` => `[FORTH]`

  Leave the size in address units allocated for the current string buffer. "slash-string-buf"

  primitive code = [p4_slash_str_buf]

`MAX-#$FRAMES``( -- u )``` => `[FORTH]`

  Leave the number of string frames allowed on the string frame stack for the current string space. "max-number-string-frames"

  primitive code = [p4_max_num_str_frames]

`$!``( $var.dfa $: a$ -- )``` => `[FORTH]`

  Store the string MSA on the string stack in the variable whose DFA is on the parameter stack. "string-store"

  NOTES: The only situation in which `$!` copies the string value is when it is a bound string already stored in another variable. In that case, the new copy is the one that is stored in the variable. In particular, external strings are not copied.

  If the string value held by the string variable on entry is a bound string that is also referenced deeper on the string stack, its back link is reset to point to the deepest string stack reference. If it is a bound string not deeper on the string stack and not identical to the input string, its back link is set to zero, making it garbage. If it is an external string, its MSA in the variable is simply written over by that popped from the string stack.

  primitive code = [p4_str_store]

`$@``( $var.pfa -- $: a$ )``` => `[FORTH]`

  Leave the MSA of the string held by the string variable. "string-fetch"

  primitive code = [p4_str_fetch]

`(M$:)``` => `[FORTH]`

  (no description)

  compiling word = [p4_marg_execution]

`$"``( [ccc<">] -- $: str )``` => `[FORTH]`

  Parse ccc delimited by " (double quote) and store it in data space as an mstring. If interpreting, leave the MSA on the string stack. If compiling, append run-time semantics to the current definition that leaves the MSA on the string stack. A program should not alter the stored string. An error is thrown if the quoted string length is larger than the system parameter `MAX_DATA_STR` (see `SM,`). "string-quote"

  NOTE: In contrast to `S"`, the string stored by `$"` when interpreting is not transient.

  The implementation is based on PFE code for `S"`.

  compiling word = [p4_str_quote]

`$```( [ccc<`>] -- $: str )``` => `[FORTH]`

  Parse ccc delimited by ` (back-tick). This is `"$""` with back tick instead of double quote as the delimiter. "string-back-tick"

  compiling word = [p4_str_back_tick]

`$VARIABLE``( "name" -- )``` => `[FORTH]`

          "name" execution:	( -- dfa )

  Create an ordinary Forth variable and initialize it to the address of a fixed, external, measured representation of the empty string, such as that pushed onto the string stack by `EMPTY$`. "string-variable""

  primitive code = [p4_str_variable]

`PARSE>$``( [ccc<char>] char -- $: ccc$ )``` => `[FORTH]`

  Parse the input stream up to the first occurrence of char, which is parsed away, and store the string as an external measured string. If executing in compilation mode, append run-time semantics to the current definition that leaves the MSA on the string stack. In interpretation mode, leave the MSA on the string stack, where the stored copy, unlike `PARSE>S`, is required to be nontransient.

  primitive code = [p4_parse_to_str]

`$.``( $: a$ -- )``` => `[FORTH]`

  Display the string on the terminal. If the system implementation of TYPE has its output vectored, $. uses the same vector. "string-dot"

  primitive code = [p4_str_dot]

`$2DROP``( $: a$ b$ -- )``` => `[FORTH]`

  Drop the two topmost string stack entries, marking them as garbage if appropriate. "string-two-drop"

  primitive code = [p4_str_two_drop]

`$2DUP``( $: a$ b$ -- a$ b$ a$ b$ )``` => `[FORTH]`

  Leave copies of the two topmost string stack entries. The string values are not copied. "string-two-dupe"

  primitive code = [p4_str_two_dup]

`$DEPTH``( -- n )``` => `[FORTH]`

  Leave the number of items on the string stack. "string-depth"

  primitive code = [p4_str_depth]

`$DROP``( $: a$ -- )``` => `[FORTH]`

  Drop the topmost string stack entry, marking it as garbage if it is initially bound to the top of the string stack. "string-drop"

  primitive code = [p4_str_drop]

`$DUP``( $: a$ -- a$ a$ )``` => `[FORTH]`

  Leave a copy of the topmost string stack entry. The string value is not copied. "string-dupe"

  primitive code = [p4_str_dup]

`$NIP``($: a$ b$ -- b$ )``` => `[FORTH]`

  Drop the next to top item from the string stack. "string-nip"

  NOTE: Because of essential string space bookkeeping, the system level implementation can be little more efficient than the high-level definition:

          : $NIP  $SWAP $DROP ;

  primitive code = [p4_str_nip]

`$OVER``( $: a$ b$ -- a$ b$ a$ )``` => `[FORTH]`

  Leave a copy of the next most accessible string stack entry on top of the string stack. The string value is not copied. "string-over"

  primitive code = [p4_str_over]

`$PICK``( u $: au$ ... a0$ -- au$ ... a0$ au$ )``` => `[FORTH]`

  Copy the u-th string stack entry to the top of the string stack. The string value is not copied. Throw an error if the input string stack does not have at least u+1 items. "string-pick"

  primitive code = [p4_str_pick]

`$SWAP``( $: a$ b$ -- b$ a$ )``` => `[FORTH]`

  Exchange the two most accessible strings on the string stack. Throw an error if there are less than two strings on the stack. Neither string value is copied. "string-swap"

  primitive code = [p4_str_swap]

`$EXCHANGE``( i j -- )``` => `[FORTH]`

  ($: maxth$ ... minth$ ... -- minth$ ... maxth$ ... ) Exchange the ith and jth strings on the string stack, where the top is the 0th. Throw an error if there are not at least max[i,j] + 1 strings on the stack. Neither string value is copied. "string-exchange"

  primitive code = [p4_str_exchange]

`$S>``( $: a$ -- S: a.s )``` => `[FORTH]`

  Drop a$ from the string stack and leave it as a ANS Forth string a.s, without copying. "string-s-from"

  WARNING: If a$ is a bound string, it may move or disappear at the next garbage collection, making a.s invalid. This can be avoided by sandwiching sections of code where this could occur between $GC-OFF and $GC-ON.

  primitive code = [p4_str_s_from]

`$,S``( $: a$ -- S: a.s )``` => `[FORTH]`

  Drop a$ from the string stack, copy it into data space as a measured string, and leave it as an ANS Forth string a.s. An error is thrown if the string length is larger than the system parameter `MAX_DATA_STR` (see `M,S`). "string-comma-s"

  primitive code = [p4_str_comma_s]

`$S@``( $: a$ -- a$ S: a.s )``` => `[FORTH]`

  Leave the string stack unchanged, and leave the string body address and length on the data stack. "string-s-fetch"

  WARNING: If a$ is a bound string, it may move at the next garbage collection, making a.s invalid. This can be avoided by sandwiching sections of code where this could occur between $GC-OFF and $GC-ON.

  primitive code = [p4_str_s_fetch]

`$TUCK``($: a$ b$ -- b$ a$ b$ )``` => `[FORTH]`

  Copy the top string stack item just below the second item. The string value is not copied. "string-tuck"

  NOTE: Because of essential string space bookkeeping, the system level implementation can be little more efficient than the high-level definition:

          : $TUCK  $SWAP $OVER ;

  primitive code = [p4_str_tuck]

`$TYPE``($: a$ -- )``` => `[FORTH]`

  Display the string on the terminal. A deprecated `$.` synonym. "string-type"

  primitive code = [p4_str_dot]

`>$S-COPY``( a.s -- $: a$ )``` => `[FORTH]`

  Copy the external string value whose body address and count are on the parameter stack into the string buffer and push it onto the string stack. Errors are thrown if the count is larger than `MAX_MCOUNT`, if there is not enough room in string space, even after garbage collection, or if there is an unterminated string concatenation. The input external string need not exist as a measured string. "to-string-s-copy"

  NOTE: `MAX_MCOUNT` is the largest size the count field of a measured string can hold, e.g., 255, 64K-1, or 4,096M-1. It is returned by:

          S" /DYNAMIC-STRING" ENVIRONMENT?

  WARNING: This word should not be used when the input string is a bound string because the copy operation may generate a garbage collection which invalidates its MSA.

  primitive code = [p4_to_str_s_copy]

`>$S``( a.s -- $: a$ )``` => `[FORTH]`

  Push the external ANS Forth string a.s onto the string stack, without copying the string value into the string buffer. It is an unchecked error if the Forth string a.s is not stored as an external measured string. "to-string-s"

  WARNING: If the string value of a.s is actually in the string buffer and not external, the push operation may generate a garbage collection that invalidates its MSA.

  primitive code = [p4_to_str_s]

`$+``($: a$ -- )``` => `[FORTH]`

  If a$ is the empty string, drop it and do nothing else.

  In particular, do not start a new concatenation, which would lock string space against new nonconcatenating copies.

  Otherwise append the string body to the end of the string currently being concatenated as the last string in the string buffer, and update its count field. If there is no concatenating string, start one. An error is thrown if the size of the combined string would be larger than `MAX_MCOUNT` or if there is not enough room in string space even after a garbage collection.

  If garbage collection occurs, a$ remains valid even when it is in the string buffer.

  When there is a concatenating string, concatenation is the only basic string operation that can copy a string into the string buffer. "string-plus"

  primitive code = [p4_str_plus]

`S+``( a.s -- )``` => `[FORTH]`

  If a.s is the empty string, drop it and do nothing else.

  Append the ANS Forth string body to the end of the string currently being concatenated as the last string in the string buffer, and update its count field. If there is no concatenating string, start one. An error is thrown if the size of the combined string would be larger than `MAX_MCOUNT` or if there is not enough room in string space even after a garbage collection.

  `S+` is most commonly used on external strings, not assumed to exist as mstrings. In contrast to `$+`, garbage collection could invalidate a.s if it is a dynamic string in the string buffer. `S+` can be used in that situation if garbage collection is turned off with `$GC-OFF`.

  When there is a concatenating string, concatenation is the only basic string operation that can copy a string into the string buffer. "s-plus"

  primitive code = [p4_s_plus]

`PARSE-S+``( [ccc<char>] char -- )``` => `[FORTH]`

  Parse the input stream up to the first occurrence of char, which is parsed away. If executing in compilation mode, append run-time semantics to the current definition that concatenates the characters parsed from the string. Otherwise concatenate the characters. "parse-s-plus"

  primitive code = [p4_parse_s_plus]

`ENDCAT``( -- $: cat$ | empty$ )``` => `[FORTH]`

  If there is no concatenating string, do nothing but leave the empty string. If there is, leave it as a string bound to the top of the string stack, and terminate concatenation, permitting normal copies into the string buffer. "end-cat"

  primitive code = [p4_endcat]

`$+"``( [ccc<quote>] -- )``` => `[FORTH]`

  This word is immediate. In compilation mode it appends run-time semantics to the current definition that concatenates the quoted string according to the specification for `$+`. In interpretation mode it concatenates the string. An error is thrown if the length of the quoted string is longer than the system parameter `MAX_DATA_STR` (see `M,S`). "string-plus-quote"

  compiling word = [p4_str_plus_quote]

`$+```( [ccc<backtick>] -- )``` => `[FORTH]`

  The same as `$+"` but with back tick instead of double quote as delimiter. "string-plus-back-tick"

  compiling word = [p4_str_plus_back_tick]

`#$ARGS``( -- u )``` => `[FORTH]`

  Leave the number of entries in the topmost string frame. Throw an error if the frame stack is empty. "number-string-args"

  primitive code = [p4_num_str_args]

`$ARGS{``( arg1'$ ... argN'$ "arg1 ... argN <}>" -- )``` => `[FORTH]`

           compilation: ( -- $: arg1$ ... argN$ )

  Immediate and compilation-only.

  Copy the argument strings across lines to the string buffer, push them onto the string stack with "argN" the most accessible, and make them into the top compile-time string stack frame. Compile the run-time code to make an argument frame out of the N most accessible run-time string stack entries. Inform the system text interpreter that it should compile run-time code for any white-space delimited argument encountered in the text of the definition, that concatenates the corresponding string in the run-time frame. At the semicolon terminating the definition, drop the compile-time argument frame and compile code to drop the run-time argument frame.

  The code between `$ARGS{` ... `}` and the terminating semicolon is not allowed to make a net change in the string stack depth, because that would interfere with the automatic dropping of the string argument frame at the semicolon. "string-args-brace"

  Syntax for defining a string macro GEORGE:

            : george  ($: a$ b$ c$ -- cat$ )
              $ARGS{ arg1 arg2 arg3 }
              cat" This is arg1:  " arg1 cat" ." ENDCAT $. ;

  The blank following the last argument is required. For a macro with no arguments, `$ARGS{ }` does nothing but add useless overhead and should be omitted. Two of the arguments in this example are ignored and could have been left out. Note that `ENDCAT` would not be legal in this word without something like `$.` to remove the concatenated string from the string stack before the terminating semicolon. It is normal to use an `$ARGS{ }` word as a step in a concatenation that is terminated elsewhere.

  Sample syntax using the string macro `george`:

            $" bill"  $" sue"  $" marie"  george $.

  The resulting display is:

            This is arg1:  bill.

  NOTE: Macro argument labels must be distinct from each other and from any local labels that appear in the same definition, and there is no check for that.

  NOTE: At the moment the semantics of `$ARGS{` is undefined before `DOES>`.

  immediate code = [p4_str_args_brace]

`$FRAME``( u -- )``` => `[FORTH]`

  Push the description of a string stack frame starting at the top of the string stack and containing u entries onto the string frame stack. Errors are thrown if the frame stack would overflow or if the depth of the string stack above the top frame, if there is one, is less than u. The value u = 0 is allowed. "string-frame"

  NOTE: This implementation pushes u and the string stack pointer onto the frame stack.

  primitive code = [p4_str_frame]

`$FRAME-DEPTH``( -- u )``` => `[FORTH]`

  Leave the number of string frames currently on the string frame stack. "string-frame-depth"

  primitive code = [p4_str_frame_depth]

`DROP-$FRAME``($: frame*$ i*$ -- i*s )``` => `[FORTH]`

  Drop the topmost string frame from the string frame stack, and the corresponding strings, frame*$, from the string stack. An error is thrown if either stack would underflow. The cases where the frame has zero entries on the string stack and/or there are zero or more items on the string stack above the top frame item are handled properly. "drop-string-frame"

  primitive code = [p4_drop_str_frame]

`FIND-$ARG``( s -- u true | false )``` => `[FORTH]`

  Leave true and its index u in the top string frame if the ANS Forth string matches an element of the frame, else leave false. The index of the top frame element is zero. "find-string-arg"

  primitive code = [p4_find_str_arg]

`TH-$ARG``( u -- $: arg$ )``` => `[FORTH]`

  Leave the u-th string in the topmost string frame, where the index u of the top element is zero. Throw an error if the frame stack is empty or if the top frame contains less than u+1 strings. "th-string-arg"

  primitive code = [p4_th_str_arg]

`(DROP-$FRAME)``` => `[FORTH]`

  (no description)

  compiling word = [p4_do_drop_str_frame]

`$POP``( $: a$ -- s: a$)``` => `[FORTH]`

  Abort if the string stack would underflow when popped.

  Otherwise pop the top of the string stack and push it onto the data stack.

  If the string is in the current string space and initially bound to the top of the string stack, mark it as garbage by setting its back link to `NULL` and set the garbage flag.

  This word violates the rule that only ANS Forth strings should appear on the data stack, and so is under the hood. "string-pop"

  primitive code = [p4_str_pop]

`$PUSH-EXT``( a$ -- $: a$ )``` => `[FORTH]`

  Pop an external mstring address from the data stack and push it onto the string stack after checking for room, invoking garbage collection if necessary. Not to be used with a dynamic string because a garbage collection can invalidate its address.

  This word violates the normal rule that only ANS Forth strings should appear on the data stack, and so is under the hood. "string-push-ext"

  primitive code = [p4_str_push_ext]

`$BREAKP@``( -- $stack.break.addr )``` => `[FORTH]`

  "string-break-p-fetch"

  primitive code = [p4_str_breakp_fetch]

`$BUFP@``( -- $buffer.addr )``` => `[FORTH]`

  "string-buf-p-fetch"

  primitive code = [p4_str_bufp_fetch]

`$FBREAKP@``( -- frame.stack.break.addr )``` => `[FORTH]`

  "string-f-break-p-fetch"

  primitive code = [p4_str_fbreakp_fetch]

`$FSP@``( -- frame.stack.top.addr )``` => `[FORTH]`

  "string-f-s-p-fetch"

  primitive code = [p4_str_fsp_fetch]

`$FSP0@``( -- initial.frame.stack.top.addr )``` => `[FORTH]`

  "string-f-s-p-zero-fetch"

  primitive code = [p4_str_fsp0_fetch]

`$SP@``( -- string.stack.top.addr )``` => `[FORTH]`

  "string-s-p-fetch"

  primitive code = [p4_str_sp_fetch]

`$SP0@``( -- initial.string.stack.top.addr )``` => `[FORTH]`

  "string-s-p-zero-fetch"

  primitive code = [p4_str_sp0_fetch]

`/$FRAME-ITEM``` => `[FORTH]`

  (no description)

  primitive code = [p4_slash_str_frame_item]

`/$FRAME-STACK``` => `[FORTH]`

  (no description)

  primitive code = [p4_slash_str_frame_stack]

`/$SPACE-HEADER``( -- $space.header.size )``` => `[FORTH]`

  "slash-string-space-header"

  primitive code = [p4_slash_str_space_header]

`0$SPACE``( $space.addr -- )``` => `[FORTH]`

  Clear the string buffer, string stack, and string frame stack in the string space starting at space.addr. Any string variables holding strings in the string buffer are left pointing into limbo. This may be executed with the string space in an invalid state, as long as the `/$BUF` and `MAX-#$FRAMES` fields of its string space structure are intact. "zero-string-space"

  NOTE: This word does not zero fill the string buffer.

  primitive code = [p4_zero_str_space]

`CAT$P@``( -- cat$.msa | 0 )``` => `[FORTH]`

  "cat-string-fetch"

  primitive code = [p4_cat_str_p_fetch]

`IN-$BUFFER?``( msa -- flag )``` => `[FORTH]`

  Leave true if the mstring is in the string buffer. "in-string-buffer-question"

  primitive code = [p4_in_str_buffer_Q]

## EDIT

> - builtin forth editor

`EDIT-BLOCK``( blk -- )``` => `[FORTH]`

  start the internal block-editor on the assigned block

  primitive code = [p4_edit_block]

`EDIT-TEXT``` => `[FORTH]`

  (no description)

  primitive code = [p4_edit_text]

`EDIT-ERROR``( -- )``` => `[FORTH]`

  if an error occured, this routine can be called to invoke an appropriate `EDITOR` (see also `EDIT-BLOCK`)

  primitive code = [p4_edit_error]

`EDIT-BLOCK-START``` => `"FORTH"`

  (no description)

  primitive code = [p4_edit_block]

## Forth

> Base system

`INTERPRET-NEXT``` => `"FORTH"`

  (no description)

  compiling word = [p4_interpret_next]

`INTERPRET-FIND``( CS: dest* -- dest* )``executes ( -- ) experimental` => `"FORTH"`

  check the next word from `QUERY` and try to look it up with `FIND` - if found then execute the token right away and branch out of the loop body (usually do it `AGAIN` )

  compiling word = [p4_interpret_find]

`INTERPRET-NUMBER``( CS: dest* -- dest* )``executes ( -- ) experimental` => `"FORTH"`

  check the next word from `QUERY` and try to parse it up with => ?NUMBER - if parseable then postpone the number for execution and branch out of the loop body (usually do it `AGAIN` )

  compiling word = [p4_interpret_number]

`INTERPRET-NOTHING``` => `"FORTH"`

  (no description)

  compiling word = [p4_interpret_nothing]

`INTERPRET-UNDEFINED``` => `"FORTH"`

  (no description)

  compiling word = [p4_interpret_undefined]

## Environment

> related definitions

`ENVIRONMENT?``( name-ptr name-len -- 0 | ?? name-flag! )``[ANS]` => `[FORTH]`

  check the environment for a property, usually a condition like questioning the existance of specified wordset, but it can also return some implementation properties like "WORDLISTS" (the length of the search-order) or "#LOCALS" (the maximum number of locals)

  Here it implements the environment queries as a `SEARCH-WORDLIST` in a user-visible vocabulary called `ENVIRONMENT`

        : ENVIRONMENT?
          ['] ENVIRONMENT >WORDLIST SEARCH-WORDLIST
          IF  EXECUTE TRUE ELSE  FALSE THEN ;

  primitive code = [p4_environment_Q]

`REQUIRED``( ... str-ptr str-len -- ??? )``` => `[FORTH]`

  the filename argument is loaded via `INCLUDED` as an extension package to the current system. The filename is registered in the current `ENVIRONMENT` so that it is only `INCLUDED` once (!!) if called multiple times via `REQUIRED` or `REQUIRES`

  primitive code = [p4_include_required]

`REQUIRE``( ... "file-name" -- ... )``` => `[FORTH]`

  parses the next `WORD` and passes it to `REQUIRED` this is the self-parsing version of `REQUIRED` and it does parrallel `INCLUDE` w.r.t. `INCLUDED`

  primitive code = [p4_include_require]

`NEEDS``( name -- )``` => `[FORTH]`

  A self-parsing variant of an environment-query check. It is similar to a simulation like

        : NEEDS PARSE-WORD 2DUP ENVIRONMENT?
          IF DROP ( extra value ) 2DROP ( success - be silent )
          ELSE TYPE ." not available " CR THEN ;

  however that would only match those worset-envqueries which return a single extra item under the uppermost TRUE flag in the success case. Instead it works more like

        : NEEDS PARSE-WORD 2DUP ENVIRONMENT-WORDLIST SEARCH-WORDLIST
          IF 2DROP ( success - be silent and just drop the parsed word )
          ELSE TYPE ." not available " CR THEN ;

  however we add the same extension as in `ENVIRONMENT`? as that it can automatically load a wordset module to fullfil a query that looks like "[wordsetname]-ext". Therefore, the following two lines are pretty much identical:

        LOADM floating
        NEEDS floating-ext

  the difference between the two: if somebody did provide a forth level implementation of floating-ext then that implementation might have registered a hint "floating-ext" in the environment-wordlist. This extra-hint will inhibit loading of the binary module even if it exists and not been loaded so far. The `LOADM` however will not check the `ENVIRONMENT-WORDLIST` and only check its loadlist of binary wordset modules in the system.

  It is therefore recommended to use `NEEDS` instead of `LOADM` unless you know you want the binary module, quickly and uncondtionally.

  primitive code = [p4_needs_environment]

## Exception

> + extensions

`CATCH``( catch-xt* -- 0 | throw#! )``[ANS]` => `"[ANS] FORTH"`

  execute the given execution-token and catch any exception that can be caught therein. software can arbitrarily raise an exception using `THROW` - the value 0 means there was no exception, other denote implementation dependent exception-codes.

  primitive code = [p4_catch]

`THROW``( throw#! -- [THROW] | throw# -- )``[ANS]` => `"[ANS] FORTH"`

  raise an exception - it will adjust the depth of all stacks and start interpreting at the point of the latest `CATCH` if n is null nothing happens, the -1 (ie. `FALSE` ) is the raise-code of `ABORT` - the other codes are implementation dependent and will result in something quite like `ABORT`

  primitive code = [p4_throw]

`ABORT``( -- [THROW] )``[ANS]` => `"[ANS] FORTH"`

  throw - cleanup some things and go back to the QUIT routine

        : ABORT -1 THROW ;

  primitive code = [p4_abort]

`ABORT"``( [string<">] -- [THROW] )``[ANS]` => `"[ANS] FORTH"`

  throw like `ABORT` but print an additional error-message to stdout telling what has happened.

  compiling word = [p4_abort_quote]

## Facility

> + extensions

`AT-XY``( col# row# -- )``[ANS]` => `"[ANS] FORTH"`

  move the cursor position to the given row and column of the screen. If the output device is not a terminal this will have no effect but can still send an escape sequence.

  primitive code = [p4_at_x_y]

`KEY?``( -- key-flag )``[ANS]` => `"[ANS] FORTH"`

  if a character is available from the keyboard, return true. The `KEY` word will retrieve the actual character.

  primitive code = [p4_key_question]

`PAGE``( -- )``[ANS]` => `"[ANS] FORTH"`

  `CLRSCR`

  primitive code = [p4_dot_clrscr]

`EKEY``( -- key-code# )``[ANS]` => `"[ANS] FORTH"`

  return a keyboard event, the encoding may differ, esp. that it can contain special keys.

  primitive code = [p4_ekey]

`EKEY>CHAR``( key-code# -- key-code# 0 | char# true! )``[ANS]` => `"[ANS] FORTH"`

  primitive code = [p4_ekey_to_char]

`EKEY?``( -- ekey-flag )``[ANS]` => `"[ANS] FORTH"`

  check if a character is available from the keyboard to be received - unlike `KEY`? it will not discard non-visible codes.

  primitive code = [p4_ekey_question]

`EMIT?``( -- emit-flag )``[ANS]` => `"[ANS] FORTH"`

  if `EMIT` can safely output characters without blocking the forth by waiting for an indefinite time.

  primitive code = [p4_emit_question]

`MS``( milliseconds# -- )``[ANS]` => `"[ANS] FORTH"`

  wait at least the specified milliseconds (suspend the forth tasklet)

  primitive code = [p4_ms]

`TIME&DATE``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_time_and_date]

## FACILITY-MIX

> extra words

`#!``( "...<eol>" -- )``` => `"EXTENSIONS"`

  ignores the rest of the line, defining `#!' is used to support forth scripts executed by the unix kernel

  primitive code = [p4_ignore_line]

`GETTIMEOFDAY``( -- milliseconds# epochseconds# )``[EXT]` => `"EXTENSIONS"`

  returns SVR/BSD gettimeofday(2). Incompatible with 16-bit systems as the numbers can not be properly represented, hence `TIME&DATE` is more portable.

  primitive code = [gettimeofday]

`MS@``( -- milliseconds# )``[EXT]` => `"EXTENSIONS"`

  elapsed time since start of process (or system) - in millseconds. The granularity is per clock ticks as per `ENVIRONMENT CLOCKS_PER_SEC` For the current wall clock in milliseconds, ask `GETTIMEOFDAY`.

  Remember that the process clock will wrap around at some point, therefore only use difference values between two clock reads. Also note that on many desktop systems the process scheduler ticks per 1/100s or 1/60s so that the difference of two continuous reads of the process clock will show steps of 10 to 16 milliseconds.

  see also `CLOCK@` and `MS`

  primitive code = [p4_milliseconds_fetch]

`CLOCK@``( --- clock-ticks# )``[EXT]` => `"EXTENSIONS"`

  return clock(2) - the number of clocks of this process. To get the number of seconds, divide by `CLOCKS_PER_SEC` as represented in the `ENVIROMENT` for a hosted forth system. A similar scheme is used by `MS@` to compute the clock time rounded to milliseconds (named in similarity with `MS` sleep).

  Remember that the process clock will wrap around at some point, therefore only use difference values between two clock reads.

  primitive code = [p4_clock_fetch]

## File-access

> + extensions

`BIN``( access-mode# -- access-mode#' )``[ANS]` => `"[ANS] FORTH"`

  modify the give file access-mode to be a binary-mode

  primitive code = [p4_bin]

`CLOSE-FILE``( some-file* -- some-errno# )``[ANS]` => `"[ANS] FORTH"`

  close the file and return the status-code

  primitive code = [p4_close_file]

`CREATE-FILE``( name-ptr name-len open-mode# -- name-file* name-errno# )``[ANS]` => `"[ANS] FORTH"`

  create the file with the given name and open it - returns the file id and a status code. A code of zero means success. An existing file of the same name is truncated upon open.

  primitive code = [p4_create_file]

`DELETE-FILE``( name-ptr name-len -- name-errno# )``[ANS]` => `"[ANS] FORTH"`

  delete the named file and return a status code

  primitive code = [p4_delete_file]

`FILE-POSITION``( some-file* -- p,pos# some-errno# )``[ANS]` => `"[ANS] FORTH"`

  return the current position in the file and return a status code. A code of zero means success.

  primitive code = [p4_file_position]

`FILE-SIZE``( some-file* -- s,size# some-errno# )``[ANS]` => `"[ANS] FORTH"`

  return the current size of the file and return a status code. A code of zero means success.

  primitive code = [p4_file_size]

`INCLUDE-FILE``( some-file* -- )``[ANS]` => `"[ANS] FORTH"`

  `INTERPRET` the given file

  primitive code = [p4_include_file]

`INCLUDED``( name-ptr name-len -- )``[ANS]` => `"[ANS] FORTH"`

  open the named file and then `INCLUDE-FILE` see also the interactive `INCLUDE`

  primitive code = [p4_included]

`OPEN-FILE``( name-ptr name-len open-mode# -- name-file* name-errno# )``[ANS]` => `"[ANS] FORTH"`

  open the named file with mode. returns the file id and a status code. A code of zero means success.

  primitive code = [p4_open_file]

`READ-FILE``( buf-ptr buf-len some-file* -- buf-count some-errno# )``[ANS]` => `"[ANS] FORTH"`

  fill the given string buffer with characters from the buffer. A status code of zero means success and the returned count gives the number of bytes actually read. If an error occurs the number of already transferred bytes is returned.

  primitive code = [p4_read_file]

`READ-LINE``( buf-ptr buf-len some-file* -- buf-count buf-flag some-errno# )``[ANS]` => `"[ANS] FORTH"`

  fill the given string buffer with one line from the file. A line termination character (or character sequence under WIN/DOS) may also be placed in the buffer but is not included in the final count. In other respects this function performs a `READ-FILE`

  primitive code = [p4_read_line]

`REPOSITION-FILE``( o,offset# some-file* -- some-errno# )``[ANS]` => `"[ANS] FORTH"`

  reposition the file offset - the next `FILE-POSITION` would return o.offset then. returns a status code where zero means success.

  primitive code = [p4_reposition_file]

`RESIZE-FILE``( s,size# some-file* -- some-errno# )``[ANS]` => `"[ANS] FORTH"`

  resize the give file, returns a status code where zero means success.

  primitive code = [p4_resize_file]

`WRITE-FILE``( buf-ptr buf-len some-file* -- some-errno# )``[ANS]` => `"[ANS] FORTH"`

  write characters from the string buffer to a file, returns a status code where zero means success.

  primitive code = [p4_write_file]

`WRITE-LINE``( buf-ptr buf-len some-file* -- some-errno# )``[ANS]` => `"[ANS] FORTH"`

  write characters from the string buffer to a file, and add the line-terminator to the end of it. returns a status code.

  primitive code = [p4_write_line]

`FILE-STATUS``( file-ptr file-len -- file-subcode# file-errno# )``[ANS]` => `"[ANS] FORTH"`

  check the named file - if it exists the status errno code is zero. The status subcode is implementation-specific and usually matches the file access permission bits of the filesystem.

  primitive code = [p4_file_status]

`FLUSH-FILE``( some-file* -- some-errno# )``[ANS]` => `"[ANS] FORTH"`

  flush all unsaved buffers of the file to disk. A status code of zero means success.

  primitive code = [p4_flush_file]

`RENAME-FILE``( oldname-ptr oldname-len newname-ptr newname-len -- newname-errno# )``[ANS]` => `"[ANS] FORTH"`

  rename the file named by "oldname" to the name of "newname" returns a status-code where zero means success.

  primitive code = [p4_rename_file]

## FILE-Misc

> Compatibility words

`INCLUDE``( "filename" -- ??? )``[FTH]` => `[FORTH]`

  load the specified file, see also `LOAD"` filename"

  primitive code = [p4_include]

`COPY-FILE``( src-ptr src-len dst-ptr dst-len -- copy-errno# )``[FTH]` => `[FORTH]`

  like `RENAME-FILE`, copies the file from src-name to dst-name and returns an error-code or null

  primitive code = [p4_copy_file]

`MOVE-FILE``( src-ptr src-len dst-ptr dst-len -- move-errno# )``[FTH]` => `[FORTH]`

  like `RENAME-FILE`, but also across-volumes moves the file from src-name to dst-name and returns an error-code or null

  primitive code = [p4_move_file]

`FILE-R/W``( buffer* use-block# flag? some-file* -- )``[FTH]` => `[FORTH]`

  like FIG-Forth `R/W`

  primitive code = [p4_file_rw]

`FILE-BLOCK``( use-block# some-file* -- buffer* )``[FTH]` => `[FORTH]`

  primitive code = [p4_file_block]

`FILE-BUFFER``( use-block# some-file* -- buffer* )``[FTH]` => `[FORTH]`

  primitive code = [p4_file_buffer]

`FILE-EMPTY-BUFFERS``( some-file* -- )``[FTH]` => `[FORTH]`

  primitive code = [p4_file_empty_buffers]

`FILE-FLUSH``( some-file* -- )``[FTH]` => `[FORTH]`

        simulate      : FILE-FLUSH DUP FILE-SAVE-BUFFERS FILE-EMTPY-BUFFERS ;

  primitive code = [p4_file_flush]

`FILE-LIST``( use-block# some-file* -- )``[FTH]` => `[FORTH]`

  primitive code = [p4_file_list]

`FILE-LOAD``( use-block# some-file* -- )``[FTH]` => `[FORTH]`

  primitive code = [p4_file_load]

`FILE-SAVE-BUFFERS``( some-file* -- )``[FTH]` => `[FORTH]`

  primitive code = [p4_file_save_buffers]

`FILE-THRU``( lo-block# hi-block# some-file* -- )``[FTH]` => `[FORTH]`

  see `THRU`

  primitive code = [p4_file_thru]

`FILE-UPDATE``( some-file* -- )``[FTH]` => `[FORTH]`

  primitive code = [p4_file_update]

## Floating

> point + extensions

`>FLOAT``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_to_float]

`D>F``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_d_to_f]

`F!``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_store]

`F*``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_star]

`F+``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_plus]

`F-``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_minus]

`F/``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_slash]

`F0<``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_zero_less]

`F0=``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_zero_equal]

`F<``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_less_than]

`F>D``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_to_d]

`F@``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_fetch]

`FALIGN``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_d_f_align]

`FALIGNED``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_d_f_aligned]

`FDEPTH``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_depth]

`FDROP``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_drop]

`FDUP``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_dup]

`FLITERAL``` => `"[ANS] FORTH"`

  (no description)

  compiling word = [p4_f_literal]

`FLOAT+``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_d_float_plus]

`FLOATS``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_d_floats]

`FLOOR``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_floor]

`FMAX``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_max]

`FMIN``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_min]

`FNEGATE``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_negate]

`FOVER``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_over]

`FROT``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_rot]

`FROUND``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_round]

`FSWAP``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_swap]

`REPRESENT``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_represent]

`DF!``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_store]

`DF@``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_fetch]

`DFALIGN``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_d_f_align]

`DFALIGNED``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_d_f_aligned]

`DFLOAT+``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_d_float_plus]

`DFLOATS``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_d_floats]

`F**``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_star_star]

`F.``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_dot]

`FABS``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_abs]

`FACOS``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_acos]

`FACOSH``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_acosh]

`FALOG``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_alog]

`FASIN``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_asin]

`FASINH``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_asinh]

`FATAN``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_atan]

`FATAN2``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_atan2]

`FATANH``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_atanh]

`FCOS``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_cos]

`FCOSH``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_cosh]

`FE.``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_e_dot]

`FEXP``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_exp]

`FEXPM1``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_expm1]

`FLN``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_ln]

`FLNP1``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_lnp1]

`FLOG``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_log]

`FS.``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_s_dot]

`FSIN``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_sin]

`FSINCOS``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_sincos]

`FSINH``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_sinh]

`FSQRT``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_sqrt]

`FTAN``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_tan]

`FTANH``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_tanh]

`F~``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_f_proximate]

`SET-PRECISION``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_set_precision]

`SF!``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_s_f_store]

`SF@``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_s_f_fetch]

`SFALIGN``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_align]

`SFALIGNED``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_aligned]

`SFLOAT+``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_s_float_plus]

`SFLOATS``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_s_floats]

`FLOATING-STACK``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p__floating_stack]

`MAX-FLOAT``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p__max_float]

`INTERPRET-FLOAT``( CS: dest* -- dest* )``executes ( -- F: f# ) experimental` => `"[ANS] FORTH"`

  check the next word from `QUERY` and try to parse it as a floating number - if parseable then postpone the value on the floating stack and branch out of the loop body (usually do it `AGAIN` )

  compiling word = [p4_interpret_float]

## FLOATING-Misc

> Compatibility words

`FLIT``` => `"FORTH"`

  (no description)

  primitive code = [p4_f_literal_execution]

`FP@``( -- addr )``` => `"FORTH"`

  returns the floating point stack pointer

  primitive code = [p4_f_p_fetch]

`FP!``( addr -- )``` => `"FORTH"`

  sets the floating point stack pointer - this is the inverse of `FP@`

  primitive code = [p4_f_p_store]

`F=``` => `"FORTH"`

  (no description)

  primitive code = [p4_f_equal]

`F<>``( f: a b -- s: a!=b )``` => `"FORTH"`

  primitive code = [p4_f_not_equal]

`F>``` => `"FORTH"`

  (no description)

  primitive code = [p4_f_greater_than]

`F<=``` => `"FORTH"`

  (no description)

  primitive code = [p4_f_less_than_or_equal]

`F>=``` => `"FORTH"`

  (no description)

  primitive code = [p4_f_greater_than_or_equal]

`S>F``( n -- f: x )``` => `"FORTH"`

  it's inverse is `F>S` - convert a cell parameter to floating-point.

  primitive code = [p4_s_to_f]

`FTRUNC>S``(f: x -- s: n )``` => `"FORTH"`

  The word `F>S` was sometimes defined with a different behavior than `FTRUNC>S` which is the type-cast behaviour of C according to C99 section 6.3.1.4 - truncation would also match the ANS-Forth specification for `F>D`.

  Some systems used `F>S` defined to `FROUND>S` instead. The pfe provides explicit words for both conversions, the word `FROUND>S` and `FTRUNC>S` which return single-cell parameters for a floating point number with the conversion method of `FTRUNC` or `FROUND`.

  In PFE, `F>S` is a synonym pointing to `FTRUNC>S` in analogy of the behavior of `F>D` where no explicit word exists. The inverse of `F>S` is the cast conversion of `S>F`.

  primitive code = [p4_f_trunc_to_s]

`FROUND>S``(f: x -- s: n)``` => `"FORTH"`

  complements `FTRUNC>S` for applications that expect `F>S` to be defined with a rounding behavior like

        : FROUND>S FROUND FTRUNC>S ;

  primitive code = [p4_f_round_to_s]

`FTRUNC``(f: x -- x' )``` => `"FORTH"`

  truncate towards zero, discard a fractional part. See also `FTRUNC>S` conversion and the `FROUND` and `FLOOR` adaptors.

        : FTRUNC FDUP F0< IF FCEIL ELSE FLOOR THEN ;

  (When available, uses a single call to C99 trunc() internally)

  primitive code = [p4_f_trunc]

`-FROT``(f: x1 x2 x3 -- x3 x1 x2 )``` => `"FORTH"`

  F-stack equivalent of `-ROT`

  note, some systems call this work F-ROT, here it is the inverse of `FROT`

  primitive code = [p4_minus_f_rot]

`FNIP``(f: x1 x2 -- x2 )``` => `"FORTH"`

  F-stack equivalent of `NIP`

  primitive code = [p4_f_nip]

`FTUCK``(f: x1 x2 -- x2 x1 x2 )``` => `"FORTH"`

  F-stack equivalent of `TUCK`

  primitive code = [p4_f_tuck]

`1/F``(f: x -- 1/x )``` => `"FORTH"`

  primitive code = [p4_one_over_f]

`F^2``(f: x -- x^2 )``` => `"FORTH"`

  primitive code = [p4_f_square]

`F^N``( u f: x -- x^u )``` => `"FORTH"`

  For large exponents, use F** instead. Of course u=-1 is large.

  primitive code = [p4_f_power_n]

`F2/``(f: x -- x/2 )``` => `"FORTH"`

  primitive code = [p4_f_two_slash]

`F2*``(f: x -- x*2 )``` => `"FORTH"`

  primitive code = [p4_f_two_star]

`F0>``(f: x -- s: flag )``` => `"FORTH"`

  primitive code = [p4_f_zero_greater]

`F0<>``(f: x -- s: flag )``` => `"FORTH"`

  primitive code = [p4_f_zero_not_equal]

## forth_83 forth wordset page

`2+``( a# -- a#' | a* -- a*' | a -- a' [??] )``[FTH]` => `[FORTH]`

  add 2 to the value on stack (and leave the result there)

        simulate:
          : 2+ 2 + ;

  primitive code = [p4_two_plus]

`2-``( a# -- a#' | a* -- a*' | a -- a' [??] )``[FTH]` => `[FORTH]`

  substract 2 from the value on stack (and leave the result there)

        simulate:
          : 2- 2 - ;

  primitive code = [p4_two_minus]

`?TERMINAL``` => `[FORTH]`

  (no description)

  primitive code = [p4_key_question]

`COMPILE``( "word" -- )``[FTH]` => `[FORTH]`

  compile the next word. The next word should not be immediate, in which case you would have to use `[COMPILE]`. For this reason, you should use the word `POSTPONE`, which takes care it.

        simulate:
          : COMPILE  R> DUP @ , CELL+ >R ;  ( not immediate !!! )

  compiling word = [p4_compile]

`-->``( -- )``[FTH]` => `[FORTH]`

  does increase `BLK` and refills the input-buffer from there. Does hence break interpretation of the current BLK and starts with the next. Old-style forth mechanism. You should use `INCLUDE`

        : --> ?LOADING REFILL ;

  immediate code = [p4_next_block]

`INTERPRET``` => `[FORTH]`

  (no description)

  primitive code = [p4_interpret]

`K``( -- k# )``[FTH]` => `[FORTH]`

  the 3rd loop index just like `I` and `J`

  compiling word = [p4_k]

`OCTAL``( -- )``[FTH]` => `[FORTH]`

  sets `BASE` to 8. Compare with `HEX` and `DECIMAL`

        simulate:
          : OCTAL  8 BASE ! ;

  primitive code = [p4_octal]

`SP@``( -- sp-cell* )``[FTH]` => `[FORTH]`

  the address of the top of stack. Does save it onto the stack. You could do

          : DUP  SP@ @ ;

  primitive code = [p4_s_p_fetch]

`!BITS``( x-bits# x-addr mask# -- )``[FTH]` => `[FORTH]`

  at the cell pointed to by addr, change only the bits that are enabled in mask

        simulate:
          : !BITS  >R 2DUP @ R NOT AND SWAP R> AND OR SWAP ! DROP ;

  primitive code = [p4_store_bits]

`@BITS``( x-addr mask# -- x-value# )``[FTH]` => `[FORTH]`

  see the companion word => !BITS

        simulate:
          : @BITS  SWAP @ AND ;

  primitive code = [p4_fetch_bits]

`><``( a -- a' )``[FTH] [OLD]` => `[FORTH]`

  byte-swap a word

  depracated: use `NTOHS` which does the same as this word when the local byte-order seems to have no match, and be otherwise a no-op. Note that only the two lower bytes of the top-of-cell are swapped.

  primitive code = [p4_byte_swap]

`>MOVE<``( from-addr* to-addr* count# -- )``[FTH] [OLD]` => `[FORTH]`

  see `MOVE` , does byte-swap for each word underway.

  depracated: this word has not been very useful lately. It does still stem from times of 16bit forth systems that wanted to interchange data blocks. It is better to use functionality based on `NTOHS` or `NTOHL`. Note that this word `>MOVE<` does swap each 2byte. It is not useful for byte-swapping `WCHAR` strings as the count is given in bytes, not wchar items.

  primitive code = [p4_byte_swap_move]

`**``( a# b# -- power-a# )``[FTH]` => `[FORTH]`

  raise second to top power

  primitive code = [p4_power]

`SEAL``( -- )``[FTH]` => `[FORTH]`

  looks through the search-order and kills the ONLY wordset - hence you can't access the primary vocabularies from there.

  primitive code = [p4_seal]

## Usual

> Forth extensions

`C+!``( n addr -- )``` => `"FORTH"`

  Add the low-order byte of _n_ to the byte at _addr_, removing both from the stack.

  primitive code = [p4_c_plus_store]

`VOCABULARY``( "name" -- )``[FTH]` => `"FORTH"`

  create a vocabulary of that name. If the named vocabulary is called later, it will run `((VOCABULARY))` , thereby putting it into the current search order. Special pfe-extensions are accessible via `CASE-SENSITIVE-VOC` and `SEARCH-ALSO-VOC`

        simulate:
          : VOCABULARY  CREATE ALLOT-WORDLIST
               DOES> ( the ((VOCABULARY)) runtime )
                 CONTEXT !
          ; IMMEDIATE

  primitive code = [p4_vocabulary]

`BOUNDS``( str len -- str+len str )``` => `"FORTH"`

  Convert _str len_ to range for DO-loop.

        : BOUNDS  ( str len -- str+len str )  OVER + SWAP ;

  primitive code = [p4_bounds]

`OFF!``` => `"FORTH"`

  (no description)

  primitive code = [p4_off_store]

`ON!``( addr -- )``` => `"FORTH"`

  Store -1 at _addr_. Defined in f83 as `ON`. See antonym `OFF!`.

         : ON!  ( addr -- )  -1 SWAP ! ;

  primitive code = [p4_on_store]

`PLACE``( str len addr -- )``` => `"FORTH"`

  Place the string _str len_ at _addr_, formatting it as a counted string.

        : PLACE  2DUP 2>R  1+ SWAP  MOVE  2R> C! ;
        : PLACE  2DUP C!   1+ SWAP CMOVE ;

  primitive code = [p4_place]

`+PLACE``( str len add2 -- )``` => `"FORTH"`

  Append string _str len_ to the counted string at _addr_. a.k.a. `APPEND` (being a `SYNONYM` now)

        : +PLACE   2DUP 2>R  COUNT +  SWAP MOVE ( ) 2R> C+! ;

  primitive code = [p4_append]

`C+PLACE``( char addr -- )``` => `"FORTH"`

  Append _char_ to the counted string at _addr_. a.k.a. `APPEND-CHAR` (being a `SYNONYM` now)

        : C+PLACE   DUP >R  COUNT  DUP 1+ R> C!  +  C! ;

  primitive code = [p4_append_char]

`@EXECUTE``( xt -- ? )``` => `"FORTH"`

  same as `@` `EXECUTE` , but checks for null as xt and silently ignores it. Same as in most forths where defined.

        simulate:
          : @EXECUTE  @ ?DUP IF EXECUTE THEN ;

  primitive code = [p4_fetch_execute]

`?LEAVE``( cond -- )``` => `"FORTH"`

  leave a (innermost) loop if condition is true

  compiling word = [p4_question_leave]

`NOOP``( -- )``` => `"FORTH"`

  do nothing, used as a place-holder where an execution word is needed

  primitive code = [p4_noop]

`RP@``( -- addr )``` => `"FORTH"`

  returns the return stack pointer

        example:
          : R@ RP@ @ ;

  compiling word = [p4_r_p_fetch]

`RP!``( addr -- )``` => `"FORTH"`

  sets the return stack pointer, reverse of `RP@`

  primitive code = [p4_r_p_store]

`SP!``( ... addr -- )``` => `"FORTH"`

  sets the stack pointer, reverse of `SP@`

  primitive code = [p4_s_p_store]

`-ROT``( a b c -- c a b )``` => `"FORTH"`

  inverse of `ROT`

  primitive code = [p4_dash_rot]

`CSET``( n addr -- )``` => `"FORTH"`

  set bits in byte at given address

        simulate:
          : CSET  TUCK @ SWAP OR SWAP ! ;

  primitive code = [p4_c_set]

`CRESET``( n addr -- )``` => `"FORTH"`

  reset bits in byte at given address

        simulate:
          : CRESET  TUCK @ SWAP NOT AND SWAP ! ;

  primitive code = [p4_c_reset]

`CTOGGLE``( n addr -- )``` => `"FORTH"`

  toggle bits in byte at given address

        simulate:
          : CTOGGLE  TUCK @ SWAP XOR SWAP ! ;

  primitive code = [p4_c_toggle]

`TOGGLE``( c-addr charmask -- )``` => `"FORTH"`

  toggle the bits given in charmask, see also `SMUDGE` and = UNSMUDGE

        example: the fig-style SMUDGE had been defined such
          : FIG-SMUDGE LATEST >FFA (SMUDGE#) TOGGLE ;

  primitive code = [p4_toggle]

`3DUP``( x y z -- x y z x y z )``` => `"FORTH"`

  Copy top three elements on the stack onto top of stack.

        : 3DUP   THIRD THIRD THIRD ;

  or

        : 3DUP  3 PICK 3 PICK 3 PICK ;

  primitive code = [p4_three_dup]

`3DROP``( x y z -- )``` => `"FORTH"`

  Drop the top three elements from the stack.

        : 3DROP   DROP 2DROP ;

  primitive code = [p4_three_drop]

`4DUP``( a b c d -- a b c d a b c d )``` => `"FORTH"`

        simulate:
         : 4DUP  4 PICK 4 PICK 4 PICK 4 PICK ;

  primitive code = [p4_four_dup]

`4DROP``( x y z -- )``` => `"FORTH"`

  Drop the top three elements from the stack.

        : 4DROP   2DROP 2DROP ;

  primitive code = [p4_four_drop]

`TOUPPER``( c1 -- c2 )``` => `"FORTH"`

  convert a single character to upper case

          : TOUPPER  >R _toupper ;

  primitive code = [p4_toupper]

`UPPER``( addr cnt -- )``` => `"FORTH"`

  convert string to upper case

        simulate:
          : UPPER  0 DO  DUP I +  DUP C@ UPC SWAP C!  LOOP  DROP ;

  primitive code = [p4_upper]

`LOWER``( addr cnt -- )``` => `"FORTH"`

  convert string to lower case This is not in L&P's F83 but provided for symmetry

        simulate:
          : LOWER  0 DO  DUP I +  DUP C@ >R _tolower SWAP C!  LOOP  DROP ;

  primitive code = [p4_lower]

`ASCII``( [word] -- val )``` => `"FORTH"`

  state smart version of `CHAR` or `[CHAR]` resp.

        simulate:
          : ASCII  [COMPILE] [CHAR]
                   STATE @ IF [COMPILE] LITERAL THEN ;

  compiling word = [p4_ascii]

`CONTROL``( [word] -- val )``` => `"FORTH"`

  see `ASCII`, but returns char - '@'

        simulate:
          : CONTROL  [COMPILE] [CHAR]  [CHAR] @ -
                     STATE @ IF [COMPILE] LITERAL THEN ;

  compiling word = [p4_control]

`NUMBER?``( addr -- d flag )``` => `"FORTH"`

  convert counted string to number - used in inner interpreter ( `INTERPRET` ), flags if conversion was successful

        example:
          BL WORD  HERE NUMBER? 0= IF ." not a number " THEN .

  primitive code = [p4_number_question]

`VOCS``( -- )``` => `"FORTH"`

  list all vocabularies in the system

        simulate:
          : VOCS VOC-LINK @ BEGIN DUP WHILE
                                  DUP ->WORDLIST.NAME @ ID.
                                  ->WORDLIST.LINK @
                            REPEAT DROP ;

  primitive code = [p4_vocs]

`EMITS``( n char -- )``` => `"FORTH"`

  Emit _char_ _n_ times.

        : EMITS             ( n char -- )
           SWAP 0 ?DO  DUP EMIT  LOOP DROP ;

  also compare

        : SPACES BL EMITS ;
        : SPACE BL EMIT ;

  primitive code = [p4_emits]

`FILE-CHECK``( n -- )``` => `"FORTH"`

  Check for file access error.

        \ : FILE-CHECK    ( n -- )  THROW ;
        : FILE-CHECK      ( n -- )  ABORT" File Access Error " ;

  primitive code = [p4_file_check]

`MEMORY-CHECK``( n -- )``` => `"FORTH"`

  Check for memory allocation error.

        \ : MEMORY-CHECK  ( n -- )  THROW ;
        : MEMORY-CHECK    ( n -- )  ABORT" Memory Allocation Error " ;

  primitive code = [p4_memory_check]

`++``( addr -- )``` => `"FORTH"`

  Increment the value at _addr_.

        : ++  ( addr -- )  1 SWAP +! ;

  primitive code = [p4_plus_plus]

`@++``( addr -- addr' x )``` => `"FORTH"`

  Fetch the value _x_ from _addr_, and increment the address by one cell.

        : @++  ( addr -- addr' x )  DUP CELL+ SWAP  @ ;

  primitive code = [p4_fetch_plus_plus]

`!++``( addr x -- addr' )``` => `"FORTH"`

  Store the value _x_ into _addr_, and increment the address by one cell.

        : !++  ( addr x -- addr' )  OVER !  CELL+ ;

  primitive code = [p4_store_plus_plus]

`>WORDLIST``( xt -- wordl* )``` => `"EXTENSIONS"`

  convert a `VOCABULARY`-xt into its wordlist reference (as in win32forth)

  primitive code = [p4_to_wordlist]

## FpNoStack

> Floating point + extensions

`>FLOAT``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_to_float]

`D>F``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_d_to_f]

`F!``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_store]

`F*``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_star]

`F+``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_plus]

`F-``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_minus]

`F/``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_slash]

`F0<``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_zero_less]

`F0=``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_zero_equal]

`F<``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_less_than]

`F>``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_greater_than]

`F=``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_equal]

`F<>``( f: a b -- s: a!=b )``` => `"EXTENSIONS"`

  primitive code = [p4_nofp_f_not_equal]

`F<=``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_less_than_or_equal]

`F>=``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_greater_than_or_equal]

`F>D``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_to_d]

`F@``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_fetch]

`FALIGN``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_d_f_align]

`FALIGNED``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_d_f_aligned]

`FDEPTH``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_depth]

`FDROP``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_drop]

`FDUP``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_dup]

`FLITERAL``` => `"EXTENSIONS"`

  (no description)

  compiling word = [p4_nofp_f_literal]

`FLOAT+``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_d_float_plus]

`FLOATS``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_d_floats]

`FLOOR``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_floor]

`FMAX``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_max]

`FMIN``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_min]

`FNEGATE``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_negate]

`FOVER``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_over]

`FROT``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_rot]

`FROUND``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_round]

`FSWAP``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_swap]

`REPRESENT``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_represent]

`DF!``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_store]

`DF@``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_fetch]

`DFALIGN``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_d_f_align]

`DFALIGNED``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_d_f_aligned]

`DFLOAT+``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_d_float_plus]

`DFLOATS``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_d_floats]

`F**``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_star_star]

`F.``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_dot]

`FABS``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_abs]

`FACOS``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_acos]

`FACOSH``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_acosh]

`FALOG``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_alog]

`FASIN``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_asin]

`FASINH``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_asinh]

`FATAN``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_atan]

`FATAN2``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_atan2]

`FATANH``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_atanh]

`FCOS``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_cos]

`FCOSH``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_cosh]

`FE.``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_e_dot]

`FEXP``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_exp]

`FEXPM1``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_expm1]

`FLN``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_ln]

`FLNP1``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_lnp1]

`FLOG``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_log]

`FS.``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_s_dot]

`FSIN``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_sin]

`FSINCOS``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_sincos]

`FSINH``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_sinh]

`FSQRT``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_sqrt]

`FTAN``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_tan]

`FTANH``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_tanh]

`F~``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_f_proximate]

`SET-PRECISION``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_set_precision]

`SF!``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_s_f_store]

`SF@``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_s_f_fetch]

`SFALIGN``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_align]

`SFALIGNED``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_aligned]

`SFLOAT+``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_s_float_plus]

`SFLOATS``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_nofp_s_floats]

`S>F``( n -- f: x )``` => `"EXTENSIONS"`

  it's inverse is `F>S` - convert a cell parameter to floating-point.

  primitive code = [p4_nofp_s_to_f]

`FTRUNC>S``(f: x -- s: n )``` => `"EXTENSIONS"`

  The word `F>S` was sometimes defined with a different behavior than `FTRUNC>S` which is the type-cast behaviour of C according to C99 section 6.3.1.4 - truncation would also match the ANS-Forth specification for `F>D`.

  Some systems used `F>S` defined to `FROUND>S` instead. The pfe provides explicit words for both conversions, the word `FROUND>S` and `FTRUNC>S` which return single-cell parameters for a floating point number with the conversion method of `FTRUNC` or `FROUND`.

  In PFE, `F>S` is a synonym pointing to `FTRUNC>S` in analogy of the behavior of `F>D` where no explicit word exists. The inverse of `F>S` is the cast conversion of `S>F`.

  primitive code = [p4_nofp_f_trunc_to_s]

`FROUND>S``(f: x -- s: n)``` => `"EXTENSIONS"`

  complements `FTRUNC>S` for applications that expect `F>S` to be defined with a rounding behavior like

        : FROUND>S FROUND FTRUNC>S ;

  primitive code = [p4_nofp_f_round_to_s]

`FTRUNC``(f: x -- x' )``` => `"EXTENSIONS"`

  truncate towards zero, discard a fractional part. See also `FTRUNC>S` conversion and the `FROUND` and `FLOOR` adaptors.

        : FTRUNC FDUP F0< IF FCEIL ELSE FLOOR THEN ;

  (When available, uses a single call to C99 trunc() internally)

  primitive code = [p4_nofp_f_trunc]

`-FROT``(f: x1 x2 x3 -- x3 x1 x2 )``` => `"EXTENSIONS"`

  F-stack equivalent of `-ROT`

  note, some systems call this work F-ROT, here it is the inverse of `FROT`

  primitive code = [p4_nofp_minus_f_rot]

`FNIP``(f: x1 x2 -- x2 )``` => `"EXTENSIONS"`

  F-stack equivalent of `NIP`

  primitive code = [p4_nofp_f_nip]

`FTUCK``(f: x1 x2 -- x2 x1 x2 )``` => `"EXTENSIONS"`

  F-stack equivalent of `TUCK`

  primitive code = [p4_nofp_f_tuck]

`1/F``(f: x -- 1/x )``` => `"EXTENSIONS"`

  primitive code = [p4_nofp_one_over_f]

`F^2``(f: x -- x^2 )``` => `"EXTENSIONS"`

  primitive code = [p4_nofp_f_square]

`F^N``( u f: x -- x^u )``` => `"EXTENSIONS"`

  For large exponents, use F** instead. Of course u=-1 is large.

  primitive code = [p4_nofp_f_power_n]

`F2/``(f: x -- x/2 )``` => `"EXTENSIONS"`

  primitive code = [p4_nofp_f_two_slash]

`F2*``(f: x -- x*2 )``` => `"EXTENSIONS"`

  primitive code = [p4_nofp_f_two_star]

`F0>``(f: x -- s: flag )``` => `"EXTENSIONS"`

  primitive code = [p4_nofp_f_zero_greater]

`F0<>``(f: x -- s: flag )``` => `"EXTENSIONS"`

  primitive code = [p4_nofp_f_zero_not_equal]

`MAX-FLOAT``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p__nofp_max_float]

## gforth forth wordset page

`GFORTH``` => `"ENVIRONMENT"`

  (no description)

  primitive code = [p__gforth]

## Header

> Navigation

`BODY>``( pfa -- cfa )``` => `[FORTH]`

  trying to convert a pointer to the parameter-field (PFA) to point then to the corresponding code-field (CFA) - note that this is not necessarily the inverse of `>BODY` instead it is a fast implementation assuming a `VARIABLE` thing had been used. Every use of "BODY>" is warned in the logfile.

        implementation-specific simulation:
          : BODY> CELL - ;

  primitive code = [p4_body_from]

`>LINK``( cfa -- lfa )``` => `[FORTH]`

  converts a pointer to the code-field (CFA) to point then to the corresponding link-field (LFA) - in some configurations this can be a very slow operation since the system might need to walk through all header-words in the system, looking for a `>NAME` that has the cfa and *then* returning the "N>LINK" result here - which might be none at all if the word is a `:NONAME`. Use always `>NAME` and treat this word as non-portable just like any assumption about the contents of the `>LINK`-field. Only in fig-mode and for traditional fig-mode programs, this word may possibly have enough extra assertions to be somewhat reliable. (and fig-mode did not know about `SYNONYM`s - see note at `LINK>`).

  primitive code = [p4_to_link]

`LINK>``( lfa -- cfa )``` => `[FORTH]`

  converts a pointer to the link-field (LFA) to point then to the corresponding code-field (CFA)

  BEWARE: this one does not care about `SYNONYM`s and it is the only way to get at the data of a `SYNONYM`. Therefore, if you have a synonym called A for an old word B then there is a different result using "NAME>" on an A-nfa or using "N>LINK LINK>" since the first "NAME>" will return the xt of B while the latter will return the xt of A - but executing an xt of A is an error and it will `THROW`

  this difference is intentional to allow knowledgable persons to do weird things looking around in the dictionary. The forth standard words will not give you much of a chance to get hold of the nfa of a `SYNONYM` word anyway - asking `FIND` for a word A will return the execution token of B immediatly and "NAME>" on that one lead to the nfa of B and not that of A.

  primitive code = [p4_link_from]

`>NAME``( cfa -- nfa )``` => `[FORTH]`

  converts a pointer to the code-field (CFA) to point then to the corresponding name-field (NFA)

        implementation-specific simulation:
          : >NAME  >LINK L>NAME ;

  primitive code = [p4_to_name]

`NAME>``( nfa -- cfa )``` => `[FORTH]`

  converts a pointer to the name-field (NFA) to point then to the corresponding code-field (CFA)

  In all cases but a `SYNONYM` the pfe will behave not unlike the original fig-forth did - being identical to `N>LINK` `LINK>` .

  primitive code = [p4_name_from]

`L>NAME``( lfa -- nfa )``` => `[FORTH]`

  converts a pointer to the link-field (LFA) to point then to the corresponding name-field (CFA) - this one is one of the slowest operation available. One should always use the inverse operation `N>LINK` and cache an older value if that is needed. Some words might be linked but they do not have a name-field (just the other fields) but this word can not detect that and will try to look into the bits of the dictionary anway in the assumption that there is something - and if done in the wrong place it might even segfault. Only in fig-mode and for traditional fig-mode programs, this word may possibly have enough extra assertions to be somewhat reliable. (and fig-mode did not know about `SYNONYM`s - see note at `LINK>`).

        implementation-specific configure-dependent fig-only simulation:
        : L>NAME BEGIN DUP C@ 128 AND 0= WHILE 1- REPEAT ;

  primitive code = [p4_l_to_name]

`N>LINK``( nfa -- lfa )``` => `[FORTH]`

  converts a pointer to the name-field (NFA) to point then to the corresponding link-field (LFA) - this operation is quicker than the inverse `L>NAME`. This word is a specific implementation detail and should not be used by normal users - instead use always `NAME>` which is much more portable. Many systems may possibly not even have a `>LINK`-field in the sense that a `@` on this adress will lead to another `>NAME`. Any operation on the resulting `>LINK`-adress is even dependent on the current configuration of PFE - only in fig-mode you are asserted to have the classic detail. (and fig-mode did not know about `SYNONYM`s - see note at `LINK>`).

        implementation-specific configure-dependent fig-only simulation:
          : N>LINK  C@ + ;

  primitive code = [p4_n_to_link]

`NAME>STRING``( name-token -- str-ptr str-len )``` => `[FORTH]`

  convert a name-token into a string-span, used to detect the name for a word and print it. The word `ID.` can be defined as

        : ID. NAME>STRING TYPE ;

  the implementation of `NAME>STRING` depends on the header layout that is defined during the configuration of the forth system.

        : NAME>STRING COUNT 31 AND ; ( for fig-like names )
        : NAME>STRING COUNT ;        ( default, name is a simple counted string )
        : NAME>STRING @ ZCOUNT ;     ( name-token is a pointer to a C-level string )
        : NAME>STRING COUNT 31 AND   ( hybrid of fig-like and zero-terminated )
             DUP 31 = IF DROP 1+ ZCOUNT THEN
        ;
        : NAME>STRING HEAD:: COUNT CODE:: PAD PLACE PAD ; ( different i86 segments )

  primitive code = [p4_name_to_string]

`LATEST``( -- nfa )``` => `[FORTH]`

  return the NFA of the lateset definition in the `CURRENT` vocabulary

  primitive code = [p4_latest]

`>FFA``( nfa -- ffa )``obsolete` => `[FORTH]`

  converts a pointer to the name-field (NFA) to point then to the corresponding flag-field (FFA) - in traditinal Forth this is the same address. pfe _can_ do different.

        implementation-specific configure-dependent simulation:
          : FFA  1- ;

  primitive code = [p4_to_ffa]

`FFA>``( ffa -- nfa )``obsolete` => `[FORTH]`

  converts a pointer to the flag-field (FFA) to point then to the corresponding name-field (NFA) - in traditinal Forth this is the same address. pfe _can_ do different.

        implementation-specific configure-dependent simulation:
          : FFA  1+ ;

  primitive code = [p4_ffa_from]

`NAME-FLAGS@``( nfa -- nfa-flags )``` => `[FORTH]`

  get the nfa-flags that corresponds to the nfa given. Note that in the fig-style would include the nfa-count in the lower bits. (see `NAME-FLAGS!`)

  primitive code = [p4_name_flags_fetch]

`NAME-FLAGS!``( nfa-flags nfa -- )``` => `[FORTH]`

  set the nfa-flags of nfa given. Note that in the fig-style the nfa-flags would include the nfa-count in the lower bits - therefore this should only set bits that had been previously retrieved with `NAME-FLAGS@`

        : IMMEDIATE LAST @ NAME-FLAGS@ IMMEDIATE-MASK OR LAST @ NAME-FLAGS! ;

  primitive code = [p4_name_flags_store]

`HEADER,``( str-ptr str-len -- )``` => `[FORTH]`

  `CREATE` a new header in the dictionary from the given string, without CFA

        usage: : VARIABLE  BL WORD COUNT HEADER, DOVAR , ;

  primitive code = [p4_header_comma]

`$HEADER``( bstring -- )``` => `[FORTH]`

  `CREATE` a new header in the dictionary from the given string with the variable runtime (see `HEADER,` and `CREATE:`)

        usage: : VARIABLE  BL WORD $HEADER ;

  primitive code = [p4_str_header]

`SMUDGE``` => `[FORTH]`

  (no description)

  primitive code = [p4_smudge]

`HIDE``( -- )``` => `[FORTH]`

  the FIG definition toggles the `SMUDGE` bit, and not all systems have a smudge bit - instead one should use `REVEAL` or `HIDE`

        : HIDE LAST @ FLAGS@ SMUDGE-MASK XOR LAST @ FLAGS! ;

  primitive code = [p4_hide]

`REVEAL``( -- )``` => `[FORTH]`

  the FIG definition toggles the `SMUDGE` bit, and not all systems have a smudge bit - instead one should use `REVEAL` or `HIDE`

        : REVEAL LAST @ FLAGS@ SMUDGE-MASK INVERT AND LAST @ FLAGS! ;
        : REVEAL LAST @ CHAIN-INTO-CURRENT ;

  primitive code = [p4_reveal]

`RECURSIVE``( -- )``` => `[FORTH]`

  `REVEAL` the current definition making it `RECURSIVE` by its own name instead of using the ans-forth word to `RECURSE`.

        ' REVEAL ALIAS RECURSIVE IMMEDIATE

  immediate code = [p4_reveal]

`(CHECK-DEPRECATED:)``` => `[FORTH]`

  (no description)

  primitive code = [p4_check_deprecated]

`ALIAS``( some-xt* "name" -- )``[EXT]` => `[FORTH]`

  create a defer word that is initialized with the given x-token. `DO-ALIAS`

  primitive code = [p4_alias]

`IS``( xt-value [word] -- )``` => `[FORTH]`

  set a `DEFER` word (in pfe: set the DOES-field - which is the BODY-field in ans-mode and therefore the same as `TO` / in fig-mode the DOES-field is one cell higher up than for a `CREATE:` `VARIABLE` Use `IS` freely on each DOES-words in both modes).

        : IS '
          STATE @ IF LITERAL, POSTPONE >DOES-BODY POSTPONE !
          ELSE >DOES-BODY ! THEN
        ; IMMEDIATE

  compiling word = [p4_is]

`DEFER!``( xt-value xt-defer -- )``` => `[FORTH]`

  A Forth200x definition that is not very useful.

  primitive code = [p4_defer_store]

`DEFER@``( xt1 -- xt2 )``` => `[FORTH]`

  get the execution token xt2 that would be executed by the `DEFER` identified by xt1.

  This command is used to obtain the execution contents of a deferred word. A typical use would be to retrieve and save the execution behavior of the deferred word, set the deferred word to a new behavior, and then later restore the old behavior.

  If the deferred word identified by _xt1_ is associated with some other deferred word, _xt2_ is the execution token of that other deferred word. To retrieve the execution token of the word currently associated with that other deferred word, use the phrase DEFER@ DEFER@ .

  Experience: BEHAVIOR was used many years in OpenBoot and OpenFirmware systems.

  In PFE it is the inverse of an `IS` operation and it will never fail if applied to a word with atleast a body. That's just like `IS` can be applied to almost every `DOES>` word where `DEFER@` will get the value back.

  primitive code = [p4_defer_fetch]

`ACTION-OF``( [word] -- xt-value )``` => `[FORTH]`

  get the `BEHAVIOR` of a `DEFER` word when executed. If being compiled then the ACTION-OF will be the value of [word] at the time of execution and not that of compilation time (non-constant).

  In PFE it does actually pick whatever is stored in the DOES-field of a word and therefore ACTION-OF may applied to all DOES-words.

  compiling word = [p4_action_of]

## HELP

> System with Headers

`(HELP)``` => `[FORTH]`

  (no description)

  primitive code = [p4_paren_help]

## HOST-K12

> extensions

`OPEN-TERMINAL-LOGFILE``( s-buf s-len -- )``` => `"FORTH"`

  open terminal logfile named by the string-buffer all further output to the terminal window is also logged into this file. This is especially useful in embedded environments where the terminal connection is often not used or it is directed to a different location that does not easily allow to redirect the forth output to a file for further examination.

  primitive code = [p4_open_terminal_logfile]

`CLOSE-TERMINAL-LOGFILE``( -- )``` => `"FORTH"`

  close terminal logfile opened with `OPEN-TERMINAL-LOGFILE`

  primitive code = [p4_close_terminal_logfile]

`TERMINAL-EMULATION-STATE``( -- state* )``` => `"FORTH"`

  returns the address of the emulations state variable so it can be read and explicitly changed to another value from forth text. This is a very questionable thing to do as the emulation-state is actually an enumerated value, the ESE will just show question-marks setting this variable to something not understood.

  primitive code = [p4_terminal_emulation_state]

`TERMINAL-ANSWER-LINK``( -- sap#* )``` => `"FORTH"`

  send terminal-output as a data-message to the specified link sap. Unlike `TERMINAL-OUTPUT-LINK` the data-messages are in line-mode. The flushed characters are buffered until a non-printable character is seen. This is somewhat more useful when treating pfe as a print service and testing machine, but can not provide for interactivity.

        60 TERMINAL-ANSWER-LINK !
        ...
        TERMINAL-ANSWER-LINK OFF

  primitive code = [p4_terminal_answer_link]

`TERMINAL-OUTPUT-LINK``( -- sap#* )``` => `"FORTH"`

  send terminal-output as a data-message to the specified link sap. This can be used in an embedded systems for a terminal session simulation. setting zero-sap will disable sending message-frames (the zero sap is therefore not usable for output-to-link). The startup default is zero.

        60 TERMINAL-OUTPUT-LINK !
        ...
        TERMINAL-OUTPUT-LINK OFF

  primitive code = [p4_terminal_output_link]

`TERMINAL-INPUT-LINK``( -- sap#* )``` => `"FORTH"`

  let the forth stdin-handling look for data-messages on this link too. These will be interpreted like messages that come from the interactive forth terminal. This can be used in an embedded systems for a terminal session simulation. setting zero-sap will disable interpreting these incoming data-frames as keyboard-strings (so that the zero sap is therefore not usable for an input-link!). The startup default is zero.

        60 TERMINAL-INPUT-LINK !
        ...
        TERMINAL-INPUT-LINK OFF

  primitive code = [p4_terminal_input_link]

## Locals

> + extensions

`(LOCAL)``` => `"[ANS] FORTH"`

  (no description)

  primitive code = [p4_paren_local]

`LOCALS|``( xN ... x2 x1 [name1 .. nameN <|>] -- )``` => `"[ANS] FORTH"`

  create local identifiers to be used in the current definition. At runtime, each identifier will be assigned a value from the parameter stack. The identifiers may be treated as if being a `VALUE` , it does also implement the ansi `TO` extensions for locals. Note that the identifiers are only valid inside the currently compiled word, the `SEE` decompiled word will show them as `<A>` `<B>` ... `<N>` a.s.o. see also `LVALUE`

  compiling word = [p4_locals_bar]

`LVALUE``( value [name] -- )``` => `"EXTENSIONS"`

  declares a single local `VALUE` using `(LOCAL)` - a sequence of `LVALUE` declarations can replace a `LOCALS|` argument, ie. `LOCALS| a b c |` is the same as `LVALUE a LVALUE b LVALUE c` . This should also clarify the runtime stack behaviour of `LOCALS|` where the stack parameters seem to be assigned in reverse order as opposed to their textual identifier declarations. compare with `VALUE` and the pfe's convenience word `VAR`.

        : LVALUE
          STATE @ IF
            VALUE
          ELSE
            BL WORD COUNT DUP (LOCAL) (TO)
          THEN
        ; IMMEDIATE

  compiling word = [p4_local_value]

`LBUFFER:``( size [name] -- )``` => `"EXTENSIONS"`

  declares a single local `VALUE` using `(LOCAL)` - which will hold the address of an area like `BUFFER:` but carved from the return-stack (as in C with alloca). This local buffer will be automatically given up at the end of the word. The return-stack-pointer will be increased only at the time of this function (and the address assigned to the `LVALUE`) so that the provided size gets determined at runtime. Note that in some configurations the forth-return-stack area is quite small - for large string operations you should consider to use a `POCKET-PAD` in pfe.

        : LBUFFER:
          STATE @ IF
            BUFFER:
          ELSE
            :NONAME ( size -- rp* ) R> RP@ - DUP RP! SWAP >R ;NONAME
            COMPILE, POSTPONE LVALUE
          THEN
        ; IMMEDIATE

  compiling word = [p4_local_buffer_var]

## Memory-Alloc

> extension

`ALLOCATE``( size# -- alloc*! 0 | 0 errno#! )``[ANS]` => `"[ANS] FORTH"`

  Allocate a chunk of memory from the system heap. use `FREE` to release the memory area back to the system. A code of zero means success.

  primitive code = [p4_allocate]

`FREE``( alloc* -- errno# )``[ANS]` => `"[ANS] FORTH"`

  Free the memory from `ALLOCATE` A code of zero means success.

  primitive code = [p4_free]

`RESIZE``( alloc* newsize# -- alloc*' errno# )``[ANS]` => `"[ANS] FORTH"`

  Resize the system memory chunk. A code of zero means success. Our implementation returns the old pointer on failure.

  primitive code = [p4_resize]

## Compatibility

> Miscellaneous words

`ok``` => `"FORTH"`

  (no description)

  primitive code = [p4_ok]

`COLD``( -- )``[FTH]` => `"FORTH"`

  cold abort - reinitialize everything and go to `QUIT` routine ... this routine is implemented as a warm-boot in pfe.

        : COLD [ ALSO ENVIRONMENT ] EMPTY SCRIPT-FILE INCLUDED QUIT ;

  primitive code = [p4_cold]

`LIT``` => `"FORTH"`

  (no description)

  primitive code = [p4_literal_execution]

`.LINE``( line# block# -- )``[FTH]` => `"FORTH"`

  primitive code = [p4_dot_line]

`UD.R``( x,x# r# -- )``[FTH]` => `"FORTH"`

  primitive code = [p4_u_d_dot_r]

`UD.``( x,x# -- )``[FTH]` => `"FORTH"`

  see also `UD`.R

  primitive code = [p4_u_d_dot]

`ID.``( some-nfa* -- )``[FTH]` => `"FORTH"`

  print the name-field pointed to by the nfa-argument. a synonym for .NAME - but this word is more portable due its heritage from fig-forth.

  in fig-forth the name-field is effectivly a bstring with some flags, so the nfa's count has to be masked out, e.g.

        : .NAME COUNT 32 AND TYPE ;

  in other pfe configurations, the name might not contain the flags it it just a counted string - and there may be even more possibilities.

        : .NAME COUNT TYPE ;

  you should more and more convert your code to use the sequence `NAME>STRING` `TYPE` which is widely regarded as the better variant.

  primitive code = [p4_id_dot]

`-ROLL``( x...[n-1] y n# -- y x...[n-1] | num# -- )``[FTH]` => `"FORTH"`

  the inverse of `ROLL`

  primitive code = [p4_dash_roll]

`RANDOM``( n# -- random# )``[FTH]` => `"FORTH"`

  returns random number with 0 <= n2 < n1)

        : RANDOM ?DUP IF _random SWAP MOD ELSE _random THEN ;

  primitive code = [p4_random]

`SRAND``( seed# -- )``[FTH]` => `"FORTH"`

  primitive code = [p4_srand]

`(UNDER+)``( n1 n2 -- n1+n2 n2 )``[FTH]` => `"FORTH"`

  quicker than

        : (UNDER+) TUCK + SWAP ; or : (UNDER+) DUP UNDER+ ;

  primitive code = [p4_under_plus]

`+TO``( val [name] -- )``[FTH]` => `"FORTH"`

  add the val to the named `VALUE` or `LOCALS|` value

  compiling word = [p4_plus_to]

`BUILD-ARRAY``( x#...[dim] dim# -- memsize# )``[FTH]` => `"FORTH"`

  writes X, n1, ... nX into the dictionary - returns product n1 * n2 * ... * nX

  primitive code = [p4_build_array]

`ACCESS-ARRAY``( x#...[dim#] array* --- array* value# )``[FTH]` => `"FORTH"`

  see `BUILD-ARRAY`

  primitive code = [p4_access_array]

`.STATUS``( -- )``[FTH]` => `"FORTH"`

  display internal variables

        : .STATUS .VERSION .CVERSION .MEMORY .SEARCHPATHS .DICTVARS .REGSUSED ;

  primitive code = [p4_dot_status]

`SOURCE-LINE``( -- source-line# )``[FTH]` => `"FORTH"`

  if `SOURCE` is from `EVALUATE` (or `QUERY` ) then the result is 0 else the line-numbers start from 1

  primitive code = [p4_source_line]

`SOURCE-NAME``( -- source-name-ptr source-name-len )``[FTH]` => `"FORTH"`

  if `SOURCE` is from `INCLUDE` then the result is the filename, otherwise a generic name for the SOURCE-ID is given.

  primitive code = [p4_source_name]

`TH'POCKET``( pocket# -- pocket-ptr pocket-len )``[FTH]` => `"FORTH"`

  returns the specified pocket as a `S"` string reference

  primitive code = [p4_th_pocket]

`POCKET-PAD``( -- pocket-ptr )``[FTH]` => `"FORTH"`

  This function Returns the next pocket. A pocket has usually the size of a maxstring, see `ENVIRONMENT /STRING` (but can be configured to be different, mostly when MAXPATH > /STRING ) Note that a pocket is a temporary and forth internal functions do sometimes call `POCKET-PAD` too, especially when building filenames and getting a literal (but temporary) string from the keyboard. Functions are not expected to hold references to this transient area any longer than building a name and calling another word with it.

  Usage of a pocket pad is a good way to make local temporary buffers superfluous that are only used to construct a temporary string that usually gets swallowed by another function.

        depracated code:
          create temp-buffer 255 allot
          : make-temp ( str buf )
                 temp-buffer place  " .tmp" count temp-buffer append
                 temp-buffer count make-file ;
        replace with this:
          : make-temp ( str buf )
               pocket-pad >r
               r place  " .tmp" count r append
               r> count make-file
          ;

  primitive code = [p4_pocket_pad]

`W@``( some-wchar* -- some-wchar# | some* -- some# [?] )``[FTH]` => `"FORTH"`

  fetch a 2byte-val from address

  primitive code = [p4_w_fetch]

`W!``( value# some-wchar* -- | value# wchar* -- [?] )``[FTH]` => `"FORTH"`

  store a 2byte-val at addressed 2byte-value

  primitive code = [p4_w_store]

`W+!``( value# some-wchar* -- | value# wchar* -- [?] )``[FTH]` => `"FORTH"`

  add a 2byte-val to addressed 2byte-value

  primitive code = [p4_w_plus_store]

`WL-HASH``( buf-ptr buf-len -- buf-hash# )``[FTH]` => `"FORTH"`

  calc hash-code for selection of thread in a threaded-vocabulary

  primitive code = [p4_wl_hash]

`TOPMOST``( some-wordlist* -- some-topmost-nfa* )``[FTH]` => `"FORTH"`

  that last valid word in the specified vocabulary

  primitive code = [p4_topmost]

`LS.WORDS``( -- )``[FTH]` => `"FORTH"`

  see `WORDS`

  primitive code = [p4_ls_words]

`LS.PRIMITIVES``( -- )``[FTH]` => `"FORTH"`

  see `WORDS`

  primitive code = [p4_ls_primitives]

`LS.COLON-DEFS``( -- )``[FTH]` => `"FORTH"`

  see `WORDS`

  primitive code = [p4_ls_cdefs]

`LS.DOES-DEFS``( -- )``[FTH]` => `"FORTH"`

  see `WORDS`

  primitive code = [p4_ls_ddefs]

`LS.CONSTANTS``( -- )``[FTH]` => `"FORTH"`

  see `WORDS`

  primitive code = [p4_ls_constants]

`LS.VARIABLES``( -- )``[FTH]` => `"FORTH"`

  see `WORDS`

  primitive code = [p4_ls_variables]

`LS.VOCABULARIES``( -- )``[FTH]` => `"FORTH"`

  see `WORDS`

  primitive code = [p4_ls_vocabularies]

`LS.MARKERS``( -- )``[FTH]` => `"FORTH"`

  see `WORDS`

  primitive code = [p4_ls_markers]

`TAB``( tab-n# -- )``[FTH]` => `"FORTH"`

  jump to next column divisible by n

  primitive code = [p4_tab]

`BACKSPACE``( -- )``[FTH]` => `"FORTH"`

  reverse of `SPACE`

  primitive code = [p4_backspace]

`?STOP``( -- stop-flag )``[FTH]` => `"FORTH"`

  check for 'q' pressed - see => ?CR

  primitive code = [p4_Q_stop]

`START?CR``( -- )``[FTH]` => `"FORTH"`

  initialized for more-like effect - see => ?CR

  primitive code = [p4_start_Q_cr]

`?CR``( -- cr-flag )``[FTH]` => `"FORTH"`

  like `CR` , stop 25 lines past `START`?CR

  primitive code = [p4_Q_cr]

`CLOSE-ALL-FILES``( -- )``[FTH]` => `"FORTH"`

  primitive code = [p4_close_all_files]

`.MEMORY``( -- )``[FTH]` => `"FORTH"`

  primitive code = [p4_dot_memory]

`(EMIT)``` => `"FORTH"`

  (no description)

  primitive code = [p4_paren_emit]

`(EXPECT)``` => `"FORTH"`

  (no description)

  primitive code = [p4_paren_expect]

`(KEY)``` => `"FORTH"`

  (no description)

  primitive code = [p4_paren_key]

`(TYPE)``` => `"FORTH"`

  (no description)

  primitive code = [p4_paren_type]

`STANDARD-I/O``( -- )``[FTH]` => `"FORTH"`

  initialize `*TYPE*` , `*EMIT*` , `*EXPECT*` and `*KEY*` to point directly to the screen I/O routines, namely `(TYPE)` , `(EMIT)` , `(EXPECT)` , `(KEY)`

  primitive code = [p4_standard_io]

`HELP``( "name" -- )``[FTH] [EXEC]` => `"FORTH"`

  will load the help module in the background and hand over the parsed name to `(HELP)` to be resolved. If no `(HELP)` word can be loaded, nothing will happen.

  primitive code = [p4_help]

`EDIT-BLOCKFILE``( "name" -- )``[FTH] [EXEC]` => `"FORTH"`

  will load the edit module in the background and look for a word called `EDIT-BLOCK` that could be used to edit the blockfile. If no `EDIT-BLOCKFILE` word can be loaded, nothing will happen. Otherwise, `OPEN-BLOCKFILE` is called followed by `0` `EDIT-BLOCK` to start editing the file at the first block.

  primitive code = [p4_edit_blockfile]

`ARGC``( -- arg-count )``[FTH]` => `"FORTH"`

  primitive code = [p4_argc]

`ARGV``( arg-n# -- arg-ptr arg-len )``[FTH]` => `"FORTH"`

  primitive code = [p4_argv]

`EXPAND-FN``( name-ptr name-len buf-ptr -- buf-ptr buf-len )``[FTH]` => `"FORTH"`

        : e.g. s" includefile" POCKET-PAD EXPAND-FN ;

  primitive code = [p4_expand_fn]

`LOAD"``( [filename<">] -- ??? )``[FTH] [OLD]` => `"FORTH"`

  load the specified file - this word can be compiled into a word-definition obsolete! use `OPEN-BLOCKFILE` name `LOAD`

  compiling word = [p4_load_quote]

`SYSTEM``( command-ptr command-len -- command-exitcode# )``[FTH]` => `"FORTH"`

  run a shell command (note: embedded systems have no shell)

  primitive code = [p4_system]

`SYSTEM"``( [command-line<">] -- command-exitcode# )``[FTH] [OLD]` => `"FORTH"`

  run a shell command (note:embedded systems have no shell) obsolete! use `S"` string" `SYSTEM`

  compiling word = [p4_system_quote]

`CREATE:``( "name" -- )``[FTH]` => `"FORTH"`

  this creates a name with the `VARIABLE` runtime. Note that this is the FIG-implemenation of `CREATE` whereas in ANS-Forth mode we have a `CREATE` identical to FIG-style `<BUILDS`

        : CREATE: BL WORD $HEADER DOVAR A, ;

  primitive code = [p4_create_var]

`BUFFER:``( size# "name" -- )``[FTH]` => `"FORTH"`

  this creates a name with the `VARIABLE` runtime and `ALLOT`s memory

        : BUFFER: BL WORD $HEADER DOVAR A, ALLOT ;

  primitive code = [p4_buffer_var]

`R'@``( R: a b -- a R: a b )``[FTH]` => `"FORTH"`

  fetch the next-under value from the returnstack. used to interpret the returnstack to hold two `LOCALS|` values. ( `R@` / `2R@` / `R>DROP` / `R"@`)

  compiling word = [p4_r_tick_fetch]

`R'!``( x R: a b -- R: x b )``[FTH]` => `"FORTH"`

  store the value into the next-under value in the returnstack. used to interpret the returnstack to hold two `LOCALS|` values. see `R'@` for inverse operation

  compiling word = [p4_r_tick_store]

`R"@``( R: a b c -- a R: a b c )``[FTH]` => `"FORTH"`

  fetch the second-under value from the returnstack. used to interpret the returnstack to hold three `LOCALS|` values. see `R"!` for inverse operation ( `R'@` `R@` / `2R@` / `R>DROP` )

  compiling word = [p4_r_quote_fetch]

`R"!``( x R: a b c -- R: x b c )``[FTH]` => `"FORTH"`

  store the value into the second-under value in the returnstack. used to interpret the returnstack to hold three `LOCALS|` values. see `R"@` for inverse operation

  compiling word = [p4_r_quote_store]

`R!``( x R: a -- R: x )``[FTH]` => `"FORTH"`

  store the value as the topmost value in the returnstack. see `R@` for inverse operation ( `R'@` / `R"@` / `2R@` / `2R!`)

  compiling word = [p4_r_store]

`2R!``( x y R: a b -- R: x y )``[FTH]` => `"FORTH"`

  store the value as the topmost value in the returnstack. see `2R@` for inverse operation ( `R'@` / `R"@` / `2R@` / `2R!`)

  compiling word = [p4_two_r_store]

`DUP>R``( val -- val R: val )``[FTH]` => `"FORTH"`

  shortcut, see `R>DROP` note again that the following will fail:

        : DUP>R DUP >R ;

  compiling word = [p4_dup_to_r]

`R>DROP``( R: val -- R: )``[FTH]` => `"FORTH"`

  shortcut (e.g. in CSI-Forth) note that the access to R is configuration dependent - only in a traditional fig-forth each NEST will be one cell wide - in case that there are no `LOCALS|` of course. And remember, the word above reads like the sequence `R>` and `DROP` but that is not quite true.

        : R>DROP R> DROP ; ( is bad - correct might be )  : R>DROP R> R> DROP >R ;

  compiling word = [p4_r_from_drop]

`2R>2DROP``( R: a b -- R: )``[FTH]` => `"FORTH"`

  this is two times `R>DROP` but a bit quicker. it is however really quick compared to the sequence `2R>` and `2DROP`

  compiling word = [p4_two_r_from_drop]

`CLEARSTACK``( -- )``[FTH]` => `"FORTH"`

  reset the parameter stack to be empty

        : CLEARSTACK  S0 SP! ;

  primitive code = [p4_clearstack]

`+UNDER``( n1 x n2 -- n1+n2 x )``[EXT]` => `"FORTH"`

  quicker than

        : UNDER+  ROT + SWAP ;

  Note: the old pfe version of UNDER+ is obsolete as it is in conflict with a comus word of the same name. The behavior of this word will continue to exist under the name of `(UNDER+)`. Users are encouraged to use the comus behavior of UNDER+ which does already exist under the name of `+UNDER`. In the future pfe will be changed to pick up the comus behavior making UNDER+ and +UNDER to be synonyms. In the current version there will be load-time warning on usages of "UNDER+".

  primitive code = [p4_plus_under]

`EXECUTES``( fkey# [word] -- )``[EXT]` => `"FORTH"`

  stores the execution token of following word into the callback pointer for the specified function-key

  primitive code = [p4_executes]

## MODULE

> - simple module implementation

`MODULE``( "name" -- old-current )``` => `"EXTENSIONS"`

  create a new `WORDLIST` with the given name. It will also have an implicit hidden vocabulary just as well and all `DEFINITIONS` will go into that hidden wordlist. Therefore the old `CURRENT` is memorized on the cs-stack.

  effectivly, CONTEXT[1] will have the wordlist-id of the public wordlist "name" and CONTEXT[0] will have the hidden wordlist contained in "name" - the hidden wordlist will always be known as HIDDEN' so that it can be re-referenced without need to use `ALSO` just to access a single definition from just another vocabulary. Note that HIDDEN' is defined immediate (a `VOCABULARY'` ) to modify the `ORDER` inside a colon definition.

        : MODULE
          CURRENT @ ( -- old-current )
          VOCABULARY
          ALSO LATEST NAME> EXECUTE ALSO DEFINITIONS
          C" HIDDEN'" $CREATE WORDLIST CONTEXT !
        ;

  primitive code = [p4_module]

`END-MODULE``( old-current -- )``` => `"EXTENSIONS"`

  clean up the cs-stack from the last `MODULE` definition. Effectivly, MODULE definitions can be nested.

        : END-MODULE ( old-current )
          PREVIOUS PREVIOUS CURRENT !

  primitive code = [p4_end_module]

`EXPORT``( old-current "name" -- old-current )``` => `"EXTENSIONS"`

  the named word in the hidden dictionary (i.e. the wordlist referenced in `CURRENT`) is exported into the public wordlist of it (i.e. which is in this implementation `CONTEXT`[1]). The actual implemenation will create a `DEFER`-word in the public wordlist withits parameter area pointing to the cfa of the hidden implementation.

        : EXPORT
          CURRENT @ CONTEXT CELL+ @ CURRENT !
          DEFER CURRENT !
          LATEST COUNT CURRENT @ SEARCH-WORDLIST
          IF LATEST NAME> >BODY ! ELSE ABORT" can't find word to export" THEN
        ;

  primitive code = [p4_export]

`EXPOSE-MODULE``( "name" -- )``` => `"EXTENSIONS"`

  affects the search order, ALSO module-wid CONTEXT ! hidden'

        : EXPOSE-MODULE
           ALSO S" HIDDEN'"
           ' DUP VOC? ABORT?" is no vocabulary" >VOC
           SEARCH-WORDLIST 0= IF " no hidden vocabulary found" THEN
           DUP VOC? ABORT?" hidden is no vocabulary" EXECUTE
        ;

  primitive code = [p4_expose_module]

`ALSO-MODULE``( "name" -- )``` => `"EXTENSIONS"`

  affects the search-order, ALSO module-wid CONTEXT !

        : ALSO-MODULE
          ' DUP VOC? ABORT?" is no vocabulary"
          ALSO EXECUTE
        ;

  primitive code = [p4_also_module]

## Option

> Words For Almost-Non-Volatile Environment

`NVRAM,WORDS``( -- )``` => `"EXTENSIONS"`

  Print a list of `WORDS` in the NVRAM buffer. Try to show also the current value, atleast for NVRAM numbers and strings. Words can be added or changed with the help of `NVRAM`,SET or `NVRAM`,USE

  Values in the NVRAM buffer will survive a `COLD` reboot, in many hosted environments however the NVRAM will be lost on program exit.

  primitive code = [p4_nvram_words]

`NVRAM,Z@``( "varname" -- z-str )``` => `"EXTENSIONS"`

  Return the string pointer of the NVRAM string item, or null if no such item exists.

  primitive code = [p4_nvram_z_fetch]

`NVRAM,S@``( "varname" -- str-ptr str-len )``` => `"EXTENSIONS"`

  Return the string span of the NVRAM string item, or double null if no such item exists.

  primitive code = [p4_nvram_s_fetch]

`NVRAM,?@``( number "varname" -- number' )``` => `"EXTENSIONS"`

  Return the value of the NVRAM value item, or leave the original number untouched (i.e. the default value for your option).

  primitive code = [p4_nvram_Q_fetch]

`NVRAM,AS``( str-ptr str-len "varname" -- )``` => `"EXTENSIONS"`

  set the NVRAM variable to the specified string.

  Some NVRAM strings do not take effect until next `COLD` reboot.

  primitive code = [p4_nvram_as]

`NVRAM,TO``( number "varname" -- )``` => `"EXTENSIONS"`

  set the NVRAM variable to the specified number.

  Most NVRAM numbers do not take effect until next `COLD` reboot.

  primitive code = [p4_nvram_to]

## posix forth wordset page

`NTOHL``( l -- l' )``` => `"EXTENSIONS"`

  if current host-encoding is bigendian, this is a NOOP otherwise byteswap the lower 32-bit bits of the topofstack. see `L@` and `L!` (being usually just `@` and `!` ) (on some platforms, the upper bits are erased, on others not)

  primitive code = [p4_ntohl]

`HTONL``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_ntohl]

`NTOHS``( w -- w' )``` => `"EXTENSIONS"`

  if current host-encoding is bigendian, this is a NOOP otherwise byteswap the lower 16-bit bits of the topofstack. see `W@` and `W!` (on some platforms, the upper bits are erased, on others not)

  primitive code = [p4_ntohs]

`HTONS``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_ntohs]

## Search-order

> + extensions

`DEFINITIONS``( -- )``` => `"[ANS] FORTH"`

  make the current context-vocabulary the definition-vocabulary, that is where new names are declared in. see `ORDER`

  primitive code = [p4_definitions]

`GET-CURRENT``( -- voc )``` => `"[ANS] FORTH"`

  return the current definition vocabulary, see `DEFINITIONS`

  primitive code = [p4_get_current]

`GET-ORDER``( -- vocn ... voc1 n )``` => `"[ANS] FORTH"`

  get the current search order onto the stack, see `SET-ORDER`

  primitive code = [p4_get_order]

`SEARCH-WORDLIST``( str-ptr str-len voc -- 0 | xt 1 | xt -1 )``` => `"[ANS] FORTH"`

  almost like `FIND` or `(FIND)` -- but searches only the specified vocabulary.

  primitive code = [p4_search_wordlist]

`SET-CURRENT``( voc -- )``` => `"[ANS] FORTH"`

  set the definition-vocabulary. see `DEFINITIONS`

  primitive code = [p4_set_current]

`SET-ORDER``( vocn ... voc1 n -- )``` => `"[ANS] FORTH"`

  set the search-order -- probably saved beforehand using `GET-ORDER`

  primitive code = [p4_set_order]

`WORDLIST``( -- voc )``` => `"[ANS] FORTH"`

  return a new vocabulary-body for private definitions.

  primitive code = [p4_wordlist]

`ALSO``( -- )``` => `"[ANS] FORTH"`

  a `DUP` on the search `ORDER` - each named vocabulary replaces the topmost `ORDER` vocabulary. Using `ALSO` will make it fixed to the search-order. (but it is not nailed in trap-conditions as if using `DEFAULT-ORDER` )

        order:   vocn ... voc2 voc1 -- vocn ... voc2 voc1 voc1

  primitive code = [p4_also]

`ORDER``( -- )``` => `"[ANS] FORTH"`

  show the current search-order, followed by the `CURRENT` `DEFINITIONS` vocabulary and the `ONLY` base vocabulary

  primitive code = [p4_order]

`PREVIOUS``( -- )``` => `"[ANS] FORTH"`

  the invers of `ALSO` , does a `DROP` on the search `ORDER` of vocabularies.

        order: vocn ... voc2 voc1 -- vocn ... voc2
        example: ALSO PRIVATE-VOC DEFINTIONS (...do some...) PREVIOUS DEFINITIONS

  primitive code = [p4_previous]

`DEFAULT-ORDER``( -- )``` => `"FORTH"`

  nail the current search `ORDER` so that it will even survive a trap-condition. This default-order can be explicitly loaded with `RESET-ORDER`

  primitive code = [p4_default_order]

`RESET-ORDER``( -- )``` => `"FORTH"`

  load the `DEFAULT-ORDER` into the current search `ORDER` - this is implicitly done when a trap is encountered.

  primitive code = [p4_reset_order]

## Shell

> like words

`$PID``( -- pid )``` => `"EXTENSIONS"`

  calls system's `getpid`

  primitive code = [p4_getpid]

`$UID``( -- val )``` => `"EXTENSIONS"`

  calls system's `getuid`

  primitive code = [p4_getuid]

`$EUID``( -- val )``` => `"EXTENSIONS"`

  calls system's `geteuid`

  primitive code = [p4_geteuid]

`$GID``( -- val )``` => `"EXTENSIONS"`

  calls system's `getgid`

  primitive code = [p4_getgid]

`UMASK``( val -- ret )``` => `"EXTENSIONS"`

  calls system's `umask`

  primitive code = [p4_umask]

`$HOME``( -- str-ptr str-len )``` => `"EXTENSIONS"`

  calls system's `getenv(HOME)`

  primitive code = [p4_home]

`$USER``( -- str-ptr str-len )``` => `"EXTENSIONS"`

  calls system's `getenv(USER)`

  primitive code = [p4_user]

`$CWD``( -- str-ptr str-len )``` => `"EXTENSIONS"`

  calls system's `getcwd`

  primitive code = [p4_cwd]

`PWD``( -- )``` => `"EXTENSIONS"`

  calls system's `getcwd` and prints it to the screen

        : PWD  $CWD TYPE ;

  primitive code = [p4_pwd]

`RM``` => `"EXTENSIONS"`

  (no description)

  compiling word = [p4_remove]

`TOUCH``` => `"EXTENSIONS"`

  (no description)

  compiling word = [p4_touch]

`CHDIR``( bstring -- )``` => `"EXTENSIONS"`

  change the current directory. ( (under VxWorks it is global! do not use in scripts!!) )

  primitive code = [p4_chdir]

`RMDIR``` => `"EXTENSIONS"`

  (no description)

  compiling word = [p4_rmdir]

`MKDIR``` => `"EXTENSIONS"`

  (no description)

  compiling word = [p4_md]

`LN``` => `"EXTENSIONS"`

  (no description)

  compiling word = [p4_link]

`MV``` => `"EXTENSIONS"`

  (no description)

  compiling word = [p4_mv]

`LL``` => `"EXTENSIONS"`

  (no description)

  compiling word = [p4_ll]

`LS``` => `"EXTENSIONS"`

  (no description)

  compiling word = [p4_ls]

`CP``` => `"EXTENSIONS"`

  (no description)

  compiling word = [p4_cp]

## Signals

> Extension

`RAISE-SIGNAL``( signal# -- ior )``[FTH]` => `"FORTH"`

  primitive code = [p4_raise_signal]

`FORTH-SIGNAL``( handler-xt* signal# -- old-signal-xt* )``[FTH]` => `"FORTH"`

  install signal handler - return old signal handler

  primitive code = [p4_forth_signal]

`RAISE-SIGNAL.DROP``` => `"FORTH"`

  (no description)

  primitive code = [p4_raise]

## smart-go

> interpreter

`SMART-INTERPRET-INIT``( -- )``` => `"EXTENSIONS"`

  creates a set of interpret-words that are used in the inner interpreter, so if a word is unknown to the interpreter-loop it will use the first char of that word, attach it to an "interpret-" prefix, and tries to use that `IMMEDIATE`-=>'DEFER'-word on the rest of the word. This `SMART-INTERPRET-INIT` will set up words like interpret-" so you can write `"hello"` instead of `" hello"` and it creates interpret-\ so that words like `\if-unix` are ignoring the line if the word `\if-unknown` is unknown in itself. This is usually not activated on startup.

  primitive code = [p4_smart_interpret_init]

`SMART-INTERPRET!``( -- )``` => `"EXTENSIONS"`

  enables/disables the SMART-INTERPRET extension in `INTERPRET` , (actually stores an XT in `DEFER` inside the mainloop interpreter)

  primitive code = [p4_smart_interpret_store]

## StackHelp

> TypeChecking extension

`|(``( [string<rp>] -- )``[EXT]` => `"EXTENSIONS"`

  add a checkstack notation for the LAST word or just try to match the given notation with the stacklayout traced so far - possibly casting a few types as needed.

  immediate code = [p4_stackhelpcomment]

`STACKHELP``( [name] -- )``[EXT]` => `"EXTENSIONS"`

  show the stackhelp info registered for this name.

  immediate code = [p4_stackhelp]

`STACKHELPS``( [name] -- )``[EXT]` => `"EXTENSIONS"`

  show all possible stackhelps for this name.

  immediate code = [p4_stackhelps]

`STACKHELP-DEBUG``` => `"EXTENSIONS"`

  (no description)

  primitive code = [stackhelp_debug]

`NARROW-CHANGER(``( changer# "stackhelp<rp>" -- )``[EXT]` => `"EXTENSIONS"`

  primitive code = [p4_narrow_changer]

`NARROW-INPUTLIST(``( changer# "stackhelp<rp>" -- )``[EXT]` => `"EXTENSIONS"`

  primitive code = [p4_narrow_inputlist]

`NARROW-OUTPUTLIST(``( changer# "stackhelp<rp>" -- )``[EXT]` => `"EXTENSIONS"`

  primitive code = [p4_narrow_outputlist]

`NARROW-INPUT-VARIANT(``( variant# changer# "stackhelp<rp>" -- )``[EXT]` => `"EXTENSIONS"`

  0 = default, 1 = 'S', 2 = 'R', ... 4 = 'P', ... 7 = 'M', .. 14 = 'F'

  primitive code = [p4_narrow_input_variant]

`NARROW-OUTPUT-VARIANT(``( variant# changer# "stackhelp<rp>" -- )``[EXT]` => `"EXTENSIONS"`

  primitive code = [p4_narrow_output_variant]

`NARROW-INPUT-STACK(``( stk-char variant# changer# "stackhelp<rp>" -- )``[EXT]` => `"EXTENSIONS"`

  0 = default, 1 = 'S', 2 = 'R', ... 4 = 'P', ... 7 = 'M', .. 14 = 'F'

  primitive code = [p4_narrow_input_stack]

`NARROW-OUTPUT-STACK(``( stk-char variant# changer# "stackhelp<rp>" -- )``[EXT]` => `"EXTENSIONS"`

  primitive code = [p4_narrow_output_stack]

`NARROW-INPUT-ARGUMENT(``( arg# stk-char variant# changer# "stackhelp<rp>" -- )``[EXT]` => `"EXTENSIONS"`

  0 = default, 1 = 'S', 2 = 'R', ... 4 = 'P', ... 7 = 'M', .. 14 = 'F' arg# is [0] = TOS and [1] = UNDER, same as the pick values where 3 2 1 0 2 pick . =:= 2

  primitive code = [p4_narrow_input_argument]

`NARROW-OUTPUT-ARGUMENT(``( arg# stk-char variant# changer# "stackhelp<rp>" -- )``[EXT]` => `"EXTENSIONS"`

  arg# is [0] = TOS and [1] = UNDER, same as the pick values where 3 2 1 0 2 pick . =:= 2

  primitive code = [p4_narrow_output_argument]

`NARROW-INPUT-ARGUMENT-NAME(``( arg# stk-char variant# changer# "stackhelp<rp>" -- )``[EXT]` => `"EXTENSIONS"`

  0 = default, 1 = 'S', 2 = 'R', ... 4 = 'P', ... 7 = 'M', .. 14 = 'F' arg# is [0] = TOS and [1] = UNDER, same as the pick values where 3 2 1 0 2 pick . =:= 2

  primitive code = [p4_narrow_input_argument_name]

`NARROW-OUTPUT-ARGUMENT-NAME(``( arg# stk-char variant# changer# "stackhelp<rp>" -- )``[EXT]` => `"EXTENSIONS"`

  arg# is [0] = TOS and [1] = UNDER, same as the pick values where 3 2 1 0 2 pick . =:= 2

  primitive code = [p4_narrow_output_argument_name]

`NARROW-INPUT-ARGUMENT-TYPE(``( arg# stk-char variant# changer# "stackhelp<rp>" -- )``[EXT]` => `"EXTENSIONS"`

  0 = default, 1 = 'S', 2 = 'R', ... 4 = 'P', ... 7 = 'M', .. 14 = 'F' arg# is [0] = TOS and [1] = UNDER, same as the pick values where 3 2 1 0 2 pick . =:= 2

  primitive code = [p4_narrow_input_argument_type]

`NARROW-OUTPUT-ARGUMENT-TYPE(``( arg# stk-char which# "stackhelp<rp>" -- )``[EXT]` => `"EXTENSIONS"`

  arg# is [0] = TOS and [1] = UNDER, same as the pick values where 3 2 1 0 2 pick . =:= 2

  primitive code = [p4_narrow_output_argument_type]

`CANONIC-INPUT-TYPE(``( arg# stk-char variant# changer# "stackhelp<rp>" -- )``[EXT]` => `"EXTENSIONS"`

  0 = default, 1 = 'S', 2 = 'R', ... 4 = 'P', ... 7 = 'M', .. 14 = 'F' arg# is [0] = TOS and [1] = UNDER, same as the pick values where 3 2 1 0 2 pick . =:= 2

  primitive code = [p4_canonic_input_type]

`CANONIC-OUTPUT-TYPE(``( arg# stk-char variant# changer# "stackhelp<rp>" -- )``[EXT]` => `"EXTENSIONS"`

  arg# is [0] = TOS and [1] = UNDER, same as the pick values where 3 2 1 0 2 pick . =:= 2

  primitive code = [p4_canonic_output_type]

`REWRITER-TEST(``( "tracked-stack -- input-stack<rp>" -- )``[EXT]` => `"EXTENSIONS"`

  suppose that the left side is a tracked stack line during compiling and the right side is a candidate changer input stack. Test whethr the candidate does match and the complete changer would be allowed to run a rewrite in the track stack buffer.

  Possible conditions include: the left side has not enough arguments or... any argument on the right side has a type specialization that does not match as a valid suffix to their counterpart on the left side.

  primitive code = [p4_rewriter_test]

`REWRITER-INPUT-ARG(``( arg# "tracked-stack -- changer<rp>" -- )``[EXT]` => `"EXTENSIONS"`

  suppose that the left side is a tracked stack line during compiling and the right side is a candidate changer input stack. Assume the righthand candidate does match - look at the given argument on the left side and show the prefix being copied to the output trackstack when the rewrite-rule is gettin applied later.

  primitive code = [p4_rewriter_input_arg]

`REWRITE-LINE(``( "stack-layout<rp>" -- )``[EXT]` => `"EXTENSIONS"`

  fill rewrite-buffer with a stack-layout to be processed. see `REWRITE-SHOW.`

  primitive code = [p4_rewrite_line]

`REWRITE-SHOW.``( -- )``[EXT]` => `"EXTENSIONS"`

  show current rewrite-buffer.

  primitive code = [p4_rewrite_show]

`REWRITE-STACK-TEST(``( "stackhelp<rp>" -- )``[EXT]` => `"EXTENSIONS"`

  check whether this stackhelp does match on current rewrite-buffer and say oK/No respectivly.

  primitive code = [p4_rewrite_stack_test]

`REWRITE-INPUT-ARG(``( arg# "stackhelp<rp>" -- )``[EXT]` => `"EXTENSIONS"`

  check whether this stackhelp does match on current rewrite-buffer and in the given input match show us the argument but only the good prefix i.e. the type constraint being cut off already.

  primitive code = [p4_rewrite_input_arg]

`REWRITE-STACK-RESULT(``( "stackhelp<rp>" -- )``[EXT]` => `"EXTENSIONS"`

  rewrite the current rewrite-buffer and show the result that would occur with this stackhelp being applied.

  primitive code = [p4_rewrite_stack_result]

`NARROW-INPUT-NOTATION(``( notation# changer# "stackhelp<rp>" -- )``[EXT]` => `"EXTENSIONS"`

  primitive code = [p4_narrow_input_notation]

`NARROW-OUTPUT-NOTATION(``( notation# changer# "stackhelp<rp>" -- )``[EXT]` => `"EXTENSIONS"`

  primitive code = [p4_narrow_output_notation]

`REWRITE-STACKDEF-TEST(``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_rewrite_stackdef_test]

`REWRITE-STACKDEF-RESULT(``( "stackhelp<rp>" -- )``[EXT]` => `"EXTENSIONS"`

  assume: only one changer (if more are provided then only the first is used) only one stackdef variant in inputlist

  primitive code = [p4_rewrite_stackdef_result]

`REWRITE-CHANGER-SELECT(``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_rewrite_changer_select]

`REWRITE-CHANGER-EXPAND(``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_rewrite_changer_expand]

`REWRITE-CHANGER-RESULT(``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_rewrite_changer_result]

`REWRITE-TEST(``( "stackhelp<rp>" -- )``[EXT]` => `"EXTENSIONS"`

  Test whether the given changer would match the current line. assume: only one changer (if more are provided then only the first is used)

  primitive code = [p4_rewrite_test]

`REWRITE-SELECT(``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_rewrite_select]

`REWRITE-EXPAND(``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_rewrite_expand]

`REWRITE-RESULT(``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_rewrite_result]

## String

> + extensions

`-TRAILING``( str-ptr str-len -- str-ptr str-len' )``` => `"[ANS] FORTH"`

  check the given buffer if it contains whitespace at its end. If so, shorten str-len to meet the last non-whitespace character in the buffer.

  primitive code = [p4_dash_trailing]

`/STRING``( str-ptr str-len n -- str-ptr' str-len' )``` => `"[ANS] FORTH"`

  shorten the buffer from the beginning by n characters, i.e.

         str-ptr += n ;
         str-len -= n;

  primitive code = [p4_slash_string]

`BLANK``( str-ptr str-len -- )``` => `"[ANS] FORTH"`

  `FILL` a given buffer with `BL` blanks

  primitive code = [p4_blank]

`CMOVE``( from-ptr to-ptr len# -- )``` => `"[ANS] FORTH"`

  memcpy an area from->to for len bytes, starting at the lower addresses, see `CMOVE>`

  primitive code = [p4_cmove]

`CMOVE>``( from-ptr to-ptr len# -- )``` => `"[ANS] FORTH"`

  memcpy an area from->to for len bytes, starting with the higher addresses, see `CMOVE`

  primitive code = [p4_cmove_up]

`COMPARE``( str1-ptr str1-len str2-ptr str2-len -- diff# )``` => `"[ANS] FORTH"`

  compare both str-buffers, return 0 if they are equal, -1 if lower or shorter, and 1 if greater or longer

  primitive code = [p4_compare]

`SEARCH``( str1-ptr str1-len str2-ptr str2-len -- str1-ptr' str1-len' flag )``` => `"[ANS] FORTH"`

  search the str-buffer1 for the text of str-buffer2, if it is contained return TRUE and return buffer-values that point to the contained string, otherwise return FALSE and leave the original str-buffer1.

  primitive code = [p4_search]

`SLITERAL``( C: str-ptr str-len -- S: str-ptr str-len )``` => `"[ANS] FORTH"`

  this word does almost the same as `LITERAL` - it takes an `S"` string as specified in the CS-STACK at compile time and compiles into the current definition where it is returned as if there were a direct string-literal. This can be used to compute a string-literal at compile-time and hardwire it.

        example:
          : ORIGINAL-HOME  [ $HOME COUNT ] SLITERAL ; ( -- str-ptr str-len )

  compiling word = [p4_sliteral]

## STRUCT

> - simple struct implementation

`STRUCT``( "name" -- here zero-offset )``` => `"EXTENSIONS"`

  begin definition of a new structure (mpe.000)

        : STRUCT CREATE  !CSP
          HERE
          0 DUP ,
        DOES>
          @
        ;

  primitive code = [p4_struct]

`END-STRUCT``( here some-offset -- )``` => `"EXTENSIONS"`

  terminate definition of a new structure (mpe.000)

        : END-STRUCT  SWAP !  ?CSP ;

  primitive code = [p4_end_struct]

`SUBRECORD``( outer-offset "name" -- outer-offset here zero-offset )``` => `"EXTENSIONS"`

  begin definition of a subrecord (mpe.000)

        : STRUCT CREATE
          HERE
          0 DUP ,
        DOES>
          @
        ;

  primitive code = [p4_subrecord]

`END-SUBRECORD``( outer-offset here some-offset -- outer-offset+some )``` => `"EXTENSIONS"`

  end definition of a subrecord (mpe.000)

        : END-SUBRECORD  TUCK SWAP !  + ;

  primitive code = [p4_end_subrecord]

`ARRAY-OF``( some-offset n len "name" -- some-offset )``` => `"EXTENSIONS"`

  a `FIELD`-array

        : ARRAY-OF * FIELD ;

  primitive code = [p4_array_of]

`VARIANT``( outer-offset "name" -- outer-offset here zero-offset )``` => `"EXTENSIONS"`

  Variant records describe an alternative view of the current record or subrecord from the start to the current point. The variant need not be of the same length, but the larger is taken

        : VARIANT SUBRECORD ;

  primitive code = [p4_variant]

`END-VARIANT``( outer-offset here some-offset -- outer-offset )``` => `"EXTENSIONS"`

  terminate definition of a new variant (mpe.000)

        : END-STRUCT  TUCK SWAP !  2DUP < IF NIP ELSE DROP THEN ;

  primitive code = [p4_end_variant]

`INSTANCE``( len "name" -- )``` => `"EXTENSIONS"`

  Create a named instance of a named structure.

        : INSTANCE  CREATE ALLOT ;

  primitive code = [p4_instance]

`INSTANCE-ADDR``( len -- addr )``` => `"EXTENSIONS"`

  Create nameless instance of a structure and return base address.

        : INSTANCE-ADDR  HERE SWAP ALLOT ;

  primitive code = [p4_instance_addr]

`ENDSTRUCTURE``( here some-offset -- )``` => `"EXTENSIONS"`

  finalize a previously started `STRUCTURE` definition

        : ENDSTRUCTURE  SWAP !  ?CSP ;

  primitive code = [p4_endstructure]

`SIZEOF``( "name" -- size )``` => `"EXTENSIONS"`

  get the size-value from a previous structure definition

        : SIZEOF   ' >BODY @  STATE @ IF [COMPILE] LITERAL THEN ; IMMEDIATE

  compiling word = [p4_sizeof]

`CHAR%``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_char_mod]

`CELL%``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_cell_mod]

`WCHAR%``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_wchar_mod]

`DOUBLE%``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_double_mod]

`FLOAT%``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_float_mod]

`SFLOAT%``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_sfloat_mod]

`DFLOAT%``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_dfloat_mod]

## STRUCTS

> - simple structure implementation 0

`STRUCTURE:``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_structure]

`;STRUCTURE``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_endstructure]

`CHAR:``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_char_colon]

`WCHAR:``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_wchar_colon]

`CELL:``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_cell_colon]

`DOUBLE:``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_two_cell_colon]

`FLOAT:``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_float_colon]

`CHARS:``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_chars_colon]

`WCHARS:``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_wchars_colon]

`CELLS:``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_cells_colon]

`INTEGER:``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_cell_colon]

`POINTER:``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_cell_colon]

`STRUCT:``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_field]

`ARRAY:``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_array_of]

## System-extension

> wordset from forth-83

`<MARK``( -- DP-mark )``compile-only` => `"FORTH"`

  memorizes the current `DP` on the CS-STACK used for `<RESOLVE` later. Useful for creation of compiling words, eg. `BEGIN` , see `AHEAD`

        simulate:
          : <MARK ?COMP  HERE ;

  primitive code = [p4_backward_mark]

`<RESOLVE``( DP-mark -- )``compile-only` => `"FORTH"`

  resolves a previous `<MARK` , actually pushes the DP-address memorized at <MARK into the dictionary. Mostly used after `BRANCH` or => ?BRANCH in compiling words like `UNTIL`

        simulate:
          : <RESOLVE ?COMP  , ;

  primitive code = [p4_backward_resolve]

`MARK>``( -- DP-mark )``compile-only` => `"FORTH"`

  makes room for a pointer in the dictionary to be resolved through `RESOLVE>` and does therefore memorize that cell's address on the CS-STACK Mostly used after `BRANCH` or => ?BRANCH in compiling words like `IF` or `ELSE`

        simulate:
          : MARK> ?COMP  HERE 0 , ;

  primitive code = [p4_forward_mark]

`RESOLVE>``( DP-mark -- )``compile-only` => `"FORTH"`

  resolves a pointer created by `MARK>` Mostly used in compiling words like `THEN`

        simulate:
          : RESOLVE> ?COMP  HERE SWAP ! ;

  primitive code = [p4_forward_resolve]

`BRANCH``( -- )``` => `"FORTH"`

  compiles a branch-runtime into the dictionary that can be resolved with `MARK<`d or `<RESOLVE`. Usage:

            BRANCH MARK&lt;     or
            BRANCH &gt;RESOLVE  or ...

  this is the runtime-portion of `ELSE` - the use of `ELSE` should be preferred. See also => ?BRANCH

        : BRANCH COMPILE (BRANCH) ;

  immediate code = [p4_branch]

`?BRANCH``( -- )``` => `"FORTH"`

  compiles a cond-branch-runtime into the dictionary that can be resolved with `>MARK&`d or `RESOLVE>`. Usage:

            ?BRANCH MARK&lt;     or
            ?BRANCH &gt;RESOLVE  or ...

  this is the runtime-portion of `IF` - the use of `IF` should be preferred. See also `BRANCH`

        : ?BRANCH COMPILE (?BRANCH) ;

  immediate code = [p4_q_branch]

## Terminal

> Interface extensions

`SHOW-TERMCAP``( -- )``for debugging` => `"EXTENSIONS"`

  print the termcap strings used for input and output may give hints about what is wrong if the terminal seems to miss some functionality

  primitive code = [p4_show_termcap]

`SHOW-TERM-CONTROLS``( -- )``for debugging` => `"EXTENSIONS"`

  show the current mappings for the terminal output may give hints about what is wrong if the output seems to miss some functionality

  primitive code = [p4_show_control_strings]

`SHOW-TERM-ESC-KEYS``( -- )``for debugging` => `"EXTENSIONS"`

  show the current mappings for the terminal input may give hints about what is wrong if the input seems to miss some functionality

  primitive code = [p4_show_rawkey_strings]

`ASSUME_VT100``( -- )``` => `"EXTENSIONS"`

  load hardwired VT100-termcap into the terminal-driver

  primitive code = [p4_assume_vt100]

`ASSUME_DUMBTERM``( -- )``` => `"EXTENSIONS"`

  load hardwired DUMBTERM-termcap into the terminal-driver

  primitive code = [p4_assume_dumbterm]

`GOTOXY``( x y -- )``` => `"EXTENSIONS"`

  move the cursor to the specified position on the screen - this is usually done by sending a corresponding esc-sequence to the terminal.

  primitive code = [p4_gotoxy]

`?XY``( -- x y )``` => `"EXTENSIONS"`

  returns the cursor position on screen, on a real unix system this includes a special call to the screen driver, in remote systems this can be the expected position as seen on the client side's terminal driver.

  primitive code = [p4_question_xy]

`CLS``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_dot_clrscr]

`.CLRSCR``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_dot_clrscr]

`.CLREOL``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_dot_clreol]

`.HOME``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_dot_home]

`.HIGHLIGHT``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_dot_highlight]

`.HIGHLIGHT.OFF``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_dot_highlight_off]

`.UNDERLINE``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_dot_underline]

`.UNDERLINE.OFF``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_dot_underline_off]

`.INTENSITY``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_dot_intensity]

`.INTENSITY.OFF``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_dot_intensity_off]

`.BLINKING``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_dot_blink]

`.BLINKING.OFF``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_dot_blink_off]

`.REVERSE``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_dot_reverse]

`.REVERSE.OFF``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_dot_reverse_off]

`.NORMAL``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_dot_normal]

`.BELL``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_dot_bell]

`EKEY>FKEY``( key-code# -- key-code# 0 | fkey-code# true! )``` => `"EXTENSIONS"`

  If the input ekey value was not an extended key then flag is set to FALSE and the value is left unchanged. Compare to EKEY>CHAR for the inverse.

  If the input eky was an extended key then the value will be modified such that shifted values are transposed to their base EKEY plus `K-SHIFT-MASK` - therefore the K-SHIFT-MASK is only apropriate for the result fkey-code values of this function.

  primitive code = [p4_ekey_to_fkey]

## TERMCATCH

> support for testing

`TERM-CAPTURE-CONTROLS``( -- var-ptr )``` => `[FORTH]`

  enable/disable common visualization of terminal control sequences.

  primitive code = [p4_term_capture_controls]

`(TERM-CAPTURE-ON)``` => `[FORTH]`

  (no description)

  primitive code = [p4_paren_term_capture_on]

`(TERM-CAPTURE-OFF)``` => `[FORTH]`

  (no description)

  primitive code = [p4_paren_term_capture_off]

`(TERM-CAPTURE-BUFFER)``` => `[FORTH]`

  (no description)

  primitive code = [p4_paren_term_capture_buffer]

`(TERM-CAPTURE-RESULT)``` => `[FORTH]`

  (no description)

  primitive code = [p4_paren_term_capture_result]

`TERM-CAPTURE-ON``( capturebuffer-ptr capturebuffer-len -- )``` => `[FORTH]`

  init/start capturing terminal output

        :  TERM-CAPTURE-ON (TERM-CAPTURE-BUFFER) (TERM-CAPTURE-ON) ;

  primitive code = [p4_term_capture_on]

`TERM-CAPTURE-OFF``( -- capturebuffer-ptr capturebuffer-len )``` => `[FORTH]`

  shutdown capturing terminal output

        :  TERM-CAPTURE-OFF (TERM-CAPTURE-OFF) (TERM-CAPTURE-RESULT) ;

  primitive code = [p4_term_capture_off]

`TERMCATCH``( str-ptr str-len some-xt* -- str-ptr str-len' catch-code# )``` => `[FORTH]`

  create a catch-domain around the token to be executed. This works the same as `CATCH`. Additionally all terminal output of that word is being captured to the buffer being provided as an argument. The maximum length input argument is modified flagging the actual length of captured output stream as the output argument. Note that in most cases a `POCKET-PAD` is just not big enough, atleast many error condition notifications tend to be quite lengthy for byte counted forth strings.

        : TERMCATCH TERM-CAPTURE-ON CATCH >R TERM-CAPTURE-OFF R> ;

  primitive code = [p4_termcatch]

## TOOLBELT

> - Neil Bawd's common extensions

`[DEFINED]``( "name" -- flag )``` => `[FORTH]`

  Search the dictionary for _name_. If _name_ is found, return TRUE; otherwise return FALSE. Immediate for use in definitions.

  [DEFINED] word ( -- nfa|0 ) immediate does check for the word using find (so it does not throw like `'` ) and puts it on stack. As it is immediate it does work in compile-mode too, so it places its argument in the cs-stack then. This is most useful with a directly following `[IF]` clause, so that sth. like an `[IFDEF] word` can be simulated through `[DEFINED] word [IF]`

        : [DEFINED] BL WORD FIND NIP ; IMMEDIATE

  immediate code = [p4_defined]

`[UNDEFINED]``( "name" -- flag )``` => `[FORTH]`

  Search the dictionary for _name_. If _name_ is found, return FALSE; otherwise return TRUE. Immediate for use in definitions.

  see `[DEFINED]`

  immediate code = [p4_undefined]

`NOT``( x -- flag )``` => `[FORTH]`

  Identical to `0=`, used for program clarity to reverse the result of a previous test.

  WARNING: PFE's NOT uses bitwise complement `INVERT` instead of the logical complement `0=`, so that loading TOOLBELT will change semantics. ... this difference in semantics has caused dpans94 to depracate the word. Only if TRUE is -1 it would be identical but not all words return -1 for true.

  primitive code = [p4_zero_equal]

`C+!``( n addr -- )``` => `[FORTH]`

  Add the low-order byte of _n_ to the byte at _addr_, removing both from the stack.

  primitive code = [p4_c_plus_store]

`EMPTY``( -- )``` => `[FORTH]`

  Reset the dictionary to a predefined golden state, discarding all definitions and releasing all allocated data space beyond that state.

  primitive code = [p4_empty]

`VOCABULARY``( "name" -- )``[FTH]` => `[FORTH]`

  create a vocabulary of that name. If the named vocabulary is called later, it will run `((VOCABULARY))` , thereby putting it into the current search order. Special pfe-extensions are accessible via `CASE-SENSITIVE-VOC` and `SEARCH-ALSO-VOC`

        simulate:
          : VOCABULARY  CREATE ALLOT-WORDLIST
               DOES> ( the ((VOCABULARY)) runtime )
                 CONTEXT !
          ; IMMEDIATE

  primitive code = [p4_vocabulary]

`BOUNDS``( str len -- str+len str )``` => `[FORTH]`

  Convert _str len_ to range for DO-loop.

        : BOUNDS  ( str len -- str+len str )  OVER + SWAP ;

  primitive code = [p4_bounds]

`OFF``( addr -- )``` => `[FORTH]`

  Store 0 at _addr_. Defined in f84 as `OFF`. See antonym `ON!`.

         : OFF  ( addr -- )  0 SWAP ! ;

  primitive code = [p4_off_store]

`ON``( addr -- )``` => `[FORTH]`

  Store -1 at _addr_. See `OFF`.

         : ON  ( addr -- )  -1 SWAP ! ;

  primitive code = [p4_on_store]

`APPEND``( str len add2 -- )``` => `[FORTH]`

  Append string _str len_ to the counted string at _addr_. a.k.a. `+PLACE` of the `PLACE` family

        : APPEND   2DUP 2>R  COUNT +  SWAP MOVE ( ) 2R> C+! ;

  primitive code = [p4_append]

`APPEND-CHAR``( char addr -- )``` => `[FORTH]`

  Append _char_ to the counted string at _addr_. a.k.a. `C+PLACE` of the `PLACE` family

        : APPEND-CHAR   DUP >R  COUNT  DUP 1+ R> C!  +  C! ;

  primitive code = [p4_append_char]

`PLACE``( str len addr -- )``` => `[FORTH]`

  Place the string _str len_ at _addr_, formatting it as a counted string.

        : PLACE  2DUP 2>R  1+ SWAP  MOVE  2R> C! ;
        : PLACE  2DUP C!   1+ SWAP CMOVE ;

  primitive code = [p4_place]

`STRING,``( str len -- )``` => `[FORTH]`

  Store a string in data space as a counted string.

        : STRING, HERE  OVER 1+  ALLOT  PLACE ;

  primitive code = [p4_parse_comma]

`,"``( "<ccc><quote>" -- )``` => `[FORTH]`

  Store a quote-delimited string in data space as a counted string.

        : ," [CHAR] " PARSE  STRING, ; IMMEDIATE

  immediate code = [p4_parse_comma_quote]

`THIRD``( x y z -- x y z x )``` => `[FORTH]`

  Copy third element on the stack onto top of stack.

        : THIRD   2 PICK ;

  primitive code = [p4_third]

`FOURTH``( w x y z -- w x y z w )``` => `[FORTH]`

  Copy fourth element on the stack onto top of stack.

        : FOURTH  3 PICK ;

  primitive code = [p4_fourth]

`3DUP``( x y z -- x y z x y z )``` => `[FORTH]`

  Copy top three elements on the stack onto top of stack.

        : 3DUP   THIRD THIRD THIRD ;

  or

        : 3DUP  3 PICK 3 PICK 3 PICK ;

  primitive code = [p4_three_dup]

`3DROP``( x y z -- )``` => `[FORTH]`

  Drop the top three elements from the stack.

        : 3DROP   DROP 2DROP ;

  primitive code = [p4_three_drop]

`2NIP``( w x y z -- y z )``` => `[FORTH]`

  Drop the third and fourth elements from the stack.

        : 2NIP   2SWAP 2DROP ;

  primitive code = [p4_two_nip]

`R'@``( R: a b -- a R: a b )``[FTH]` => `[FORTH]`

  fetch the next-under value from the returnstack. used to interpret the returnstack to hold two `LOCALS|` values. ( `R@` / `2R@` / `R>DROP` / `R"@`)

  primitive code = [p4_r_tick_fetch]

`ANDIF``( p ... -- flag )``` => `[FORTH]`

  Given `p ANDIF q THEN`, _q_ will not be performed if _p_ is false.

        : ANDIF  S" DUP IF DROP " EVALUATE ; IMMEDIATE

  compiling word = [p4_andif]

`ORIF``( p ... -- flag )``` => `[FORTH]`

  Given `p ORIF q THEN`, _q_ will not be performed if _p_ is true.

        : ORIF   S" DUP 0= IF DROP " EVALUATE ; IMMEDIATE

  compiling word = [p4_orif]

`SCAN``( str len char -- str+i len-i )``` => `[FORTH]`

  Look for a particular character in the specified string.

        : SCAN
           >R  BEGIN  DUP WHILE  OVER C@ R@ -
               WHILE  1 /STRING  REPEAT THEN
           R> DROP ;

  ie. scan for first occurence of c in string

          : SCAN >R BEGIN DUP OVER C@ R@ = 0= OR WHILE
                           1- SWAP 1- SWAP REPEAT R> DROP ;

  primitive code = [p4_scan]

`SKIP``( str len char -- str+i len-i )``` => `[FORTH]`

  Advance past leading characters in the specified string.

        : SKIP
          >R  BEGIN  DUP WHILE  OVER C@ R@ =
               WHILE  1 /STRING  REPEAT THEN
           R> DROP ;

  ie. skip leading characters c

          : SKIP  >R BEGIN DUP OVER C@ R@ = OR WHILE
                           1- SWAP 1- SWAP REPEAT R> DROP ;

  primitive code = [p4_skip]

`BACK``( str len char -- str len-i )``` => `[FORTH]`

  Look for a particular character in the string from the back toward the front.

        : BACK
           >R  BEGIN  DUP WHILE
               1-  2DUP + C@  R@ =
           UNTIL 1+ THEN
           R> DROP ;

  primitive code = [p4_back]

`/SPLIT``( a m a+i m-i -- a+i m-i a i )``` => `[FORTH]`

  Split a character string _a m_ at place given by _a+i m-i_. Called "cut-split" because "slash-split" is a tongue twister.

        : /SPLIT  DUP >R  2SWAP  R> - ;

  primitive code = [p4_div_split]

`IS-WHITE``( char -- flag )``` => `[FORTH]`

  Test char for white space.

        : IS-WHITE   33 - 0< ;

  primitive code = [p4_is_white]

`TRIM``( str len -- str len-i )``` => `[FORTH]`

  Trim white space from end of string.

        : TRIM
           BEGIN  DUP WHILE
               1-  2DUP + C@ IS-WHITE NOT
           UNTIL 1+ THEN ;

  primitive code = [p4_trim]

`BL-SCAN``( str len -- str+i len-i )``` => `[FORTH]`

  Look for white space from start of string

        : BL-SCAN
           BEGIN  DUP WHILE  OVER C@ IS-WHITE NOT
           WHILE  1 /STRING  REPEAT THEN ;

  primitive code = [p4_bl_scan]

`BL-SKIP``( str len -- str+i len-i )``` => `[FORTH]`

  Skip over white space at start of string.

        : BL-SKIP
           BEGIN  DUP WHILE  OVER C@ IS-WHITE
           WHILE  1 /STRING  REPEAT THEN ;

  primitive code = [p4_bl_skip]

`STARTS?``( str len pattern len2 -- str len flag )``` => `[FORTH]`

  Check start of string.

        : STARTS?   DUP >R  2OVER  R> MIN  COMPARE 0= ;

  primitive code = [p4_starts_Q]

`ENDS?``( str len pattern len2 -- str len flag )``` => `[FORTH]`

  Check end of string.

        : ENDS?   DUP >R  2OVER  DUP R> - /STRING  COMPARE 0= ;

  primitive code = [p4_ends_Q]

`IS-DIGIT``( char -- flag )``` => `[FORTH]`

  Test _char_ for digit [0-9].

        : IS-DIGIT   [CHAR] 0 -  10 U< ;

  primitive code = [p4_is_digit]

`IS-ALPHA``( char -- flag )``` => `[FORTH]`

  Test _char_ for alphabetic [A-Za-z].

        : IS-ALPHA  32 OR  [CHAR] a -  26 U< ;

  primitive code = [p4_is_alpha]

`IS-ALNUM``( char -- flag )``` => `[FORTH]`

  Test _char_ for alphanumeric [A-Za-z0-9].

        : IS-ALNUM
           DUP IS-ALPHA  ORIF  DUP IS-DIGIT  THEN  NIP ;

  primitive code = [p4_is_alnum]

`SPLIT-NEXT-LINE``( src . -- src' . str len )``` => `[FORTH]`

  Split the next line from the string.

        : SPLIT-NEXT-LINE
           2DUP #EOL-CHAR SCAN
           DUP >R  1 /STRING  2SWAP R> - ;

  FIXME: inform Neil Bawd that this is probably not what he wanted. replace /STRING with /SPLIT here.

  primitive code = [p4_split_next_line]

`VIEW-NEXT-LINE``( src . str len -- src . str len str2 len2 )``` => `[FORTH]`

  Copy next line above current line.

        : VIEW-NEXT-LINE
           2OVER 2DUP #EOL-CHAR SCAN NIP - ;

  primitive code = [p4_view_next_line]

`NEXT-WORD``( -- str len )``` => `[FORTH]`

  Get the next word across line breaks as a character string. _len_ will be 0 at end of file.

        : NEXT-WORD
           BEGIN   BL WORD COUNT      ( str len )
               DUP IF EXIT THEN
               REFILL
           WHILE  2DROP ( ) REPEAT ;

  primitive code = [p4_next_word]

`LEXEME``( "name" -- str len )``` => `[FORTH]`

  Get the next word on the line as a character string. If it's a single character, use it as the delimiter to get a phrase.

        : LEXEME
           BL WORD ( addr) DUP C@ 1 =
               IF  CHAR+ C@ WORD  THEN
           COUNT ;

  primitive code = [p4_lexeme]

`H#``( "hexnumber" -- n )``` => `[FORTH]`

  Get the next word in the input stream as a hex single-number literal. (Adopted from Open Firmware.)

        : H#  ( "hexnumber" -- n )  \  Simplified for easy porting.
           0 0 BL WORD COUNT
           BASE @ >R  HEX  >NUMBER  R> BASE !
               ABORT" Not Hex " 2DROP          ( n)
           STATE @ IF  POSTPONE LITERAL  THEN
           ; IMMEDIATE

  immediate code = [p4_h_sh]

`\\``( "...<eof>" -- )``` => `[FORTH]`

  Ignore the rest of the input stream.

        : \\   BEGIN  -1 PARSE  2DROP  REFILL 0= UNTIL ;

  primitive code = [p4_backslash_backslash]

`FILE-CHECK``( n -- )``` => `[FORTH]`

  Check for file access error.

        \ : FILE-CHECK    ( n -- )  THROW ;
        : FILE-CHECK      ( n -- )  ABORT" File Access Error " ;

  primitive code = [p4_file_check]

`MEMORY-CHECK``( n -- )``` => `[FORTH]`

  Check for memory allocation error.

        \ : MEMORY-CHECK  ( n -- )  THROW ;
        : MEMORY-CHECK    ( n -- )  ABORT" Memory Allocation Error " ;

  primitive code = [p4_memory_check]

`++``( addr -- )``` => `[FORTH]`

  Increment the value at _addr_.

        : ++  ( addr -- )  1 SWAP +! ;

  primitive code = [p4_plus_plus]

`@+``( addr -- addr' x )``` => `[FORTH]`

  Fetch the value _x_ from _addr_, and increment the address by one cell.

        : @+  ( addr -- addr' x )  DUP CELL+ SWAP  @ ;

  primitive code = [p4_fetch_plus_plus]

`!+``( addr x -- addr' )``` => `[FORTH]`

  Store the value _x_ into _addr_, and increment the address by one cell.

        : !+  ( addr x -- addr' )  OVER !  CELL+ ;

  primitive code = [p4_store_plus_plus]

`'th``( n "addr" -- &addr[n] )``` => `[FORTH]`

  Address `n CELLS addr +`.

        : 'th     ( n "addr" -- &addr[n] )
           S" 2 LSHIFT " EVALUATE
           BL WORD COUNT EVALUATE
           S" + " EVALUATE
           ; IMMEDIATE

  compiling word = [p4_tick_th]

`(.)``` => `[FORTH]`

  (no description)

  primitive code = [p4_paren_dot]

`CELL-``( addr -- addr' )``` => `[FORTH]`

  Decrement address by one cell

        : CELL-  ( addr -- addr' )  CELL - ;

  primitive code = [p4_cell_minus]

`EMITS``( n char -- )``` => `[FORTH]`

  Emit _char_ _n_ times.

        : EMITS             ( n char -- )
           SWAP 0 ?DO  DUP EMIT  LOOP DROP ;

  also compare

        : SPACES BL EMITS ;
        : SPACE BL EMIT ;

  primitive code = [p4_emits]

`HIWORD``( xxyy -- xx )``` => `[FORTH]`

  The high half of the value.

        : HIWORD  ( xxyy -- xx )  16 RSHIFT ;

  primitive code = [p4_hiword]

`LOWORD``( xxyy -- yy )``` => `[FORTH]`

  The low half of the value.

        : LOWORD  ( xxyy -- yy )  65535 AND ;

  primitive code = [p4_loword]

`REWIND-FILE``( file-id -- ior )``` => `[FORTH]`

  Rewind the file.

        : REWIND-FILE       ( file-id -- ior )
           0 0 ROT REPOSITION-FILE ;

  primitive code = [p4_rewind_file]

## TOOLS

> Programming-Tools (without ASSEMBLER)

`.S``( -- )``` => `"[ANS] FORTH"`

  print the stack content in vertical nice format. tries to show cell-stack and float-stack side-by-side,

  Depending on configuration, there are two parameter stacks: for integers and for floating point operations. If both stacks are empty, `.S` will display the message `<stacks empty>`.

  If only the floating point stack is empty, `.S` displays the integer stack items in one column, one item per line, both in hex and in decimal like this (the first item is topmost):

        12345 HEX 67890 .S
           	424080 [00067890]
                12345 [00003039] ok

  If both stacks ar not empty, => .S displays both stacks, in two columns, one item per line

        HEX 123456.78E90 ok
        DECIMAL 123456.78E90 .S
           	   291 [00000123]          1.234568E+95
           1164414608 [45678E90] ok

  Confusing example? Remember that floating point input only works when the `BASE` number is `DECIMAL`. The first number looks like a floating point but it is a goodhex double integer too - the number base is `HEX`. Thus it is accepted as a hex number. Second try with a decimal base will input the floating point number.

  If only the integer stack is empty, => .S shows two columns, but he first columns is called `<stack empty>`, and the second column is the floating point stack, topmost item first.

  primitive code = [p4_dot_s]

`DUMP``( addr len -- )``` => `"[ANS] FORTH"`

  show a hex-dump of the given area, if it's more than a screenful it will ask using => ?CR

  You can easily cause a segmentation fault of something like that by accessing memory that does not belong to the pfe-process.

  primitive code = [p4_dump]

`SEE``( "word" -- )``` => `"[ANS] FORTH"`

  decompile word - tries to show it in re-compilable form.

  `(SEE)` tries to display the word as a reasonable indented source text. If you defined your own control structures or use extended control-flow patterns, the indentation may be suboptimal.

        simulate:
          : SEE  [COMPILE] ' (SEE) ;

  primitive code = [p4_see]

`WORDS``( -- )``` => `"[ANS] FORTH"`

  uses CONTEXT and lists the words defined in that vocabulary. usually the vocabulary to list is named directly in before.

        example:
           FORTH WORDS  or  LOADED WORDS

  primitive code = [p4_words]

`AHEAD``( -- DP-mark ORIG-magic )``compile-only` => `"[ANS] FORTH"`

        simulate:
          : AHEAD  BRANCH MARK> (ORIG#) ;

  compiling word = [p4_new_ahead]

`BYE``( -- )``no-return` => `"[ANS] FORTH"`

  should quit the forth environment completly

  primitive code = [p4_bye]

`CS-PICK``( 2a 2b 2c ... n -- 2a 2b 2c ... 2a )``` => `"[ANS] FORTH"`

  pick a value in the compilation-stack - note that the compilation stack _can_ be seperate in some forth-implemenations. In PFE the parameter-stack is used in a double-cell fashion, so CS-PICK would 2PICK a DP-mark and a COMP-magic, see `PICK`

  primitive code = [p4_cs_pick]

`CS-ROLL``( 2a 2b 2c ... n -- 2b 2c ... 2a )``` => `"[ANS] FORTH"`

  roll a value in the compilation-stack - note that the compilation stack _can_ be seperate in some forth-implemenations. In PFE the parameter-stack is used in a double-cell fashion, so CS-ROLL would 2ROLL a DP-mark and a COMP-magic, see `ROLL`

  primitive code = [p4_cs_roll]

`FORGET``( "word" -- )``` => `"[ANS] FORTH"`

        simulate:
          : FORGET  [COMPILE] '  >NAME (FORGET) ; IMMEDIATE

  primitive code = [p4_forget]

`[ELSE]``( -- )``` => `"[ANS] FORTH"`

  eat up everything upto and including the next [THEN]. count nested [IF] ... [THEN] constructs. see `[IF]`

        this word provides a simple pre-compiler mechanism

  immediate code = [p4_bracket_else]

`[IF]``( flag -- )``` => `"[ANS] FORTH"`

  check the condition in the CS-STACK. If true let the following text flow into `INTERPRET` , otherwise eat up everything upto and including the next `[ELSE]` or `[THEN]` . In case of skipping, count nested [IF] ... [THEN] constructs.

        this word provides a simple pre-compiler mechanism

  immediate code = [p4_bracket_if]

`[THEN]``` => `"[ANS] FORTH"`

  (no description)

  immediate code = [p4_noop]

`?``( addr -- )``` => `"[ANS] FORTH"`

  Display the (integer) content of at address `addr`. This word is sensitive to `BASE`

        simulate:
          : ?  @ . ;

  primitive code = [p4_question]

`CODE``( "name" -- )``` => `"[ANS] FORTH"`

  call `ALSO` and add ASSEMBLER wordlist if available. Add PROC ENTER assembler snippet as needed for the architecture into the PFA. The CFA is setup (a) with the PFA adress in traditional ITC or (b) with an infoblock as for sbr-coded colon words.

  Remember that not all architectures are support and that the ASSEMBLER wordset is not compiled into pfe by default. Use always the corresponding `END-CODE` for each `CODE` start. The new word name is not smudged.

  primitive code = [p4_create_code]

`;CODE``( -- )``` => `"[ANS] FORTH"`

  Does end the latest word (being usually some DOES> part) and enters machine-level (in EXEC-mode).

  BE AWARE: The TOOLS-EXT will not provide an `END-CODE` or any other word in the `ASSEMBLER` wordlist which is required to start any useful assembler programming. After requiring ASSEMBLER-EXT you will see a second ";CODE" in the `EXTENSIONS` wordlist that will also provide an optimized execution than the result of this standard-forth implemenation.

  The Standard-Forth implementation will actually compile a derivate of `BRANCH` into the dictionary followed by `;`. The compiled word will not jump to the target adress (following the execution token) but it will call the target adress via the host C stack. The target machine level word (C domain) will just return here for being returned (Forth domain). Hence `END-CODE` may be a simple RET, comma!

  compiling word = [p4_semicolon_code]

`END-CODE``( "name" -- )``` => `"ASSEMBLER"`

  call `PREVIOUS` and add PROC LEAVE assembler snippet as needed for the architecture - usually includes bits to "return from subroutine". Remember that not all architectures are support and PFE usually does only do variants of call-threading with a separate loop for the inner interpreter that does "call into subroutine". Some forth implementations do "jump into routine" and the PROC LEAVE part would do "jump to next routine" also known as next-threading. The sbr-call-threading is usually similar to the native subroutine-coding of the host operating system. See `CODE`

  primitive code = [p4_end_code]

## TOOLS-Misc

> Compatibility words

`VLIST``( -- )``` => `[FORTH]`

  The VLIST command had been present in FIG and other forth implementations. It has to list all accessible words. In PFE it list all words in the search order. Well, the point is, that we do really just look into the search order and are then calling `WORDS` on that Wordl. That way you can see all accessible words in the order they might be found. Uses => ?CR

  primitive code = [p4_vlist]

`!CSP``( -- )``` => `[FORTH]`

  put `SP` into `CSP` used in control-words

  primitive code = [p4_store_csp]

`?CSP``( -- )``` => `[FORTH]`

  check that `SP` == `CSP` otherwise `THROW` used in control-words

  primitive code = [p4_Q_csp]

`CS-SWAP``` => `[FORTH]`

  (no description)

  primitive code = [p4_two_swap]

`CS-DROP``` => `[FORTH]`

  (no description)

  primitive code = [p4_two_drop]

`?COMP``( -- )``` => `[FORTH]`

  check that the current `STATE` is compiling otherwise `THROW` often used in control-words

  primitive code = [p4_Q_comp]

`?EXEC``( -- )``` => `[FORTH]`

  check that the current `STATE` is executing otherwise `THROW` often used in control-words

  primitive code = [p4_Q_exec]

`?FILE``( file-id -- )``` => `[FORTH]`

  check the file-id otherwise (fixme)

  primitive code = [p4_Q_file]

`?LOADING``( -- )``` => `[FORTH]`

  check that the currently interpreted text is from a file/block, otherwise `THROW`

  primitive code = [p4_Q_loading]

`?PAIRS``( a b -- )``` => `[FORTH]`

  if compiling, check that the two magics on the `CS-STACK` are identical, otherwise throw used in control-words

  primitive code = [p4_Q_pairs]

`?STACK``( -- )``` => `[FORTH]`

  check all stacks for underflow and overflow conditions, and if such an error condition is detected `THROW`

  primitive code = [p4_Q_stack]

`DEFINED``( "name" -- flag )``` => `[FORTH]`

  Search the dictionary for _name_. If _name_ is found, return TRUE; otherwise return FALSE. Immediate for use in definitions.

  This word will actually return what `FIND` returns (the NFA). does check for the word using find (so it does not throw like `'` ) and puts it on stack. As it is immediate it does work in compile-mode too, so it places its argument in the cs-stack then. This is most useful with a directly following `[IF]` clause, so that sth. like an `[IFDEF] word` can be simulated through `[DEFINED] word [IF]`

        : DEFINED BL WORD COUNT (FIND-NFA) ;

  primitive code = [p4_defined]

`[DEFINED]``( "name" -- flag )``` => `[FORTH]`

  Search the dictionary for _name_. If _name_ is found, return TRUE; otherwise return FALSE. Immediate for use in definitions.

  [DEFINED] word ( -- nfa|0 ) immediate does check for the word using find (so it does not throw like `'` ) and puts it on stack. As it is immediate it does work in compile-mode too, so it places its argument in the cs-stack then. This is most useful with a directly following `[IF]` clause, so that sth. like an `[IFDEF] word` can be simulated through `[DEFINED] word [IF]`

        : [DEFINED] BL WORD FIND NIP ; IMMEDIATE

  immediate code = [p4_defined]

`[UNDEFINED]``( "name" -- flag )``` => `[FORTH]`

  Search the dictionary for _name_. If _name_ is found, return FALSE; otherwise return TRUE. Immediate for use in definitions.

  see `[DEFINED]`

  immediate code = [p4_undefined]

`(FORGET)``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_paren_forget]

`(DICTLIMIT)``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_paren_dictlimit]

`(DICTFENCE)``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_paren_dictfence]

## Useful

> kernel extensions

`_like:COMPILE,``` => `"EXTENSIONS"`

  (no description)

  primitive code = [p4_to_compile]

`($``( [word] -- cs-token )``compile-only` => `"EXTENSIONS"`

  takes the execution token of the following word and saves it on the compile-stack. The correspondig closing `)` will then feed it into `>COMPILE` - so this pair of word provides you with a prefix-operation syntax that you may have been seen in lisp-like languages.

          ($ IF ($ 0= A1 @ )) ($ THEN ." hello " )

  Note that an opening simple `(` paren is a comment.

  immediate code = [p4_prefix_begin]

`)``( cs-token -- )``` => `"EXTENSIONS"`

  takes the execution-token from `($` and compiles it using `>COMPILE`

  immediate code = [p4_prefix_end]

`PFE-PRINTF``( args ... format$ -- )``` => `"EXTENSIONS"`

  uses `SPRINTF` to print to a temporary 256-char buffer and prints it to stdout afterwards. See the example at `SPRINTF` of what it does internally.

  primitive code = [p4_printf]

`PFE-SPRINTF``( args ... format$ dest$ -- len-dest )``` => `"EXTENSIONS"`

  just like the standard sprintf() function in C, but the format is a counted string and accepts %#s to be the format-symbol for a forth-counted string. The result is a zeroterminated string at dest$ having a length being returned. To create a forth-counted string, you could use:

          variable A 256 ALLOT
          15 " example" " the %#s value is %i" A 1+ SPRINTF A C!
          A COUNT TYPE

  primitive code = [p4_sprintf]

`LOADF``( "filename" -- )``` => `"EXTENSIONS"`

  loads a file just like `INCLUDE` but does also put a `MARKER` in the `LOADED` dictionary that you can do a `FORGET` on to kill everything being loaded from that file.

  primitive code = [p4_loadf]

`DOER``( word -- )``` => `"EXTENSIONS"`

  In PFE it is a synonym to `DEFER` which a semistandard word. Unlike `DEFER`, the `DOER`-vector was set with an a small piece of code between `MAKE` and `;AND`. The "DOER"-word should be replaced with `DEFER` `IS`, which is easy since the `DEFER` and `DOER` point to the same internal runtime.

  primitive code = [p4_defer]

`MAKE``( [word] -- )``... ;AND` => `"EXTENSIONS"`

  make a seperated piece of code between `MAKE` and `;AND` and on execution of the `MAKE` the named word is twisted to point to this piece of code. The word is usually a `DOER` but the current implementation works on `DEFER` just as well, just as it does on other words who expect to find an execution-token in its PFA. You could even create a colon-word that starts with `NOOP` and can then make that colon-word be prefixed with the execution of the code piece. This `MAKE` does even work on `LOCALS|` and `VAR` but it is uncertain what that is good for.

  compiling word = [p4_make]

`;AND``( -- )``` => `"EXTENSIONS"`

  For the code piece between `MAKE` and `;AND` , this word will do just an `EXIT` . For the code outside of the `MAKE` construct a branch-around must be resolved then.

  compiling word = [p4_semicolon_and]

`[NOT]``( a -- a' )``` => `"EXTENSIONS"`

  executes `0=` but this word is immediate so that it does affect the cs-stack while compiling rather than compiling anything. This is useful just before words like `[IF]` to provide semantics of an `[IFNOT]`. It is most useful in conjunction with "=> [DEFINED] word" as it the sequence "`[DEFINED] word [NOT] [IF]`" can simulate "`[IFNOTDEF] word`"

  immediate code = [p4_bracket_not]

`+FIELD:``( offset "name" -- offset )``` => `"EXTENSIONS"`

  created a new name with an `OFFSET-RT` runtime using the given offset. Leave the offset-value untouched, so it can be modified with words like `CHAR+` and `CELL+` and `SFLOAT+` ; This word is the simplest way to declared structure access words in forth - the two `STRUCT` modules contain a more elaborate series of words. Use this one like:

        0                        ( a fresh definition is started )
        +FIELD: zapp.a+ CHAR+     ( zero offset from the base of the struct )
        +FIELD: zapp.b+ CELL+     ( no alignment, starts off at 1 from base )
        +FIELD: zapp+   DROP      ( store size of complete zap structure )

        0 zapp+                  ( extend the zap structure )
        +FIELD: zappx.c+ CELL+    ( a new field )
        +FIELD: zappx+   DROP     ( and save it again )

        CREATE zapp1  0 zapp+ ALLOT ( a way to allocate a strucutre )

        zapp2 zapp.b+ @         ( read a value from the field )
        16 zapp2 zapp.b+ !      ( store a value in there )

  this form is not the traditional form used in forth, it is however quite simple. Use the simplefield declaration with `/FIELD` to be compatible with traditional styles that build on top of sizeof constants in forth (which are not part of the ANS Forth standard).

  primitive code = [p4_plus_field]

`/FIELD``( offset size "name" -- offset+size )``` => `"EXTENSIONS"`

  created a new `+FIELD` name with an `OFFSET-RT` of offset. Then add the size value to the offset so that the next `/FIELD` declaration will start at the end of the field currently declared. This word is the simplest way to declared structure access words in forth - the two `STRUCT` modules contain a more elaborate series of words. This one is used like:

        0                        ( a fresh definition is started )
        /CHAR /FIELD ->zapp.a    ( zero offset from the base of the struct )
        /CELL /FIELD ->zapp.b    ( no alignment, starts off at 1 from base )
        CONSTANT /zapp           ( store size of complete zap structure )

        /zapp                    ( extend the zap structure )
        /CELL /FIELD ->zappx.c   ( a new field )
        CONSTANT /zappx          ( and save it again )

        CREATE zapp1 /zapp ALLOT ( a way to allocate a strucutre )
        /zapp BUFFER: zapp2      ( another way to do it, semi-standard )

        zapp2 ->zapp.b @         ( read a value from the field )
        16 zapp2 ->zapp.b !      ( store a value in there )

  compare also with `/CHAR` `/WCHAR` `/CELL` `/DCELL` and use `+FIELD` as the lowlevel word, can simulate as

        : /FIELD SWAP +FIELD + ;

  primitive code = [p4_slash_field]

`REPLACE-IN``( to-xt from-xt n "name" -- )``` => `"EXTENSIONS"`

  will handle the body of the named word as a sequence of cells (or tokens) and replaces the n'th occurences of from-xt into to-xt. A negative value will change all occurences. A zero value will not change any.

  primitive code = [p4_replace_in]

`(LOADF-LOCATE)``( xt -- nfa )``` => `"EXTENSIONS"`

  the implementation of `LOADF-LOCATE`

  primitive code = [p4_paren_loadf_locate]

`LOADF-LOCATE``( "name" -- )``` => `"EXTENSIONS"`

  look for the filename created by `LOADF` that had been defining the given name. `LOADF` has created a marker that is above the `INCLUDED` file and that marker has a body-value just below the `INCLUDED` file. Hence the symbol was defined during `LOADF` execution of that file.

        : LOADF-LOCATE ?EXEC POSTPONE ' (LOADF-LOCATE) .NAME ;

  primitive code = [p4_loadf_locate]

`X"``( "hex-q" -- bstring )``` => `"EXTENSIONS"`

  places a counted string on stack containing bytes specified by hex-string - the hex string may contain spaces which will delimit the bytes

        example:
           X" 41 42 4344" COUNT TYPE ( shows ABCD )

  compiling word = [p4_x_quote]

`EVALUATE-WITH``( i*x addr len xt[i*x--j*x] -- j*x )``` => `"EXTENSIONS"`

  added to be visible on the forth command line on request by MLG, he has explained the usage before a lot, you can get an idea from:

           : EVALUATE ['] INTERPRET EVALUATE-WITH ;

  The word is used internally in PFE for the loadlist evaluation of the binary modules: where previously each loadercode had its own CREATE-execution we do now call the original forthish CREATE-word like, so bootstrapping a `VARIABLE` will now call VARIABLE itself and of course we need to set up the TIB-area to point to the name of the variable that shall be created in the forth dictionary:

        : LOAD-WORD ( arg-value str-ptr str-len loader-code -- )
             CASE
               #LOAD-VARIABLE OF ['] VARIABLE EVALUATE-WITH ENDOF
               ....
             ENDCASE
             CLEARSTACK
        ;

  primitive code = [p4_evaluate_with]

`[POSSIBLY]``( [name] -- ?? )``` => `"EXTENSIONS"`

  check if the name exists, and execute it immediatly if found. Derived from POSSIBLY as seen in other forth systems.

        : [POSSIBLY] (') ?DUP IF EXECUTE THEN ; IMMEDIATE

  immediate code = [p4_bracket_possibly]

`[VOCABULARY]``( "name" -- )``` => `"EXTENSIONS"`

  create an immediate vocabulary. Provides for basic modularization.

        : [VOCABULARY] VOCABULARY IMMEDIATE ;

  primitive code = [p4_bracket_vocabulary]

`[DEF]``( -- )``` => `"EXTENSIONS"`

  immediatly set topmost `CONTEXT` voc to `CURRENT` compilation voc.

        : DEF' CURRENT @ CONTEXT ! ; IMMEDIATE

  note that in PFE most basic vocabularies are immediate, so that you can use a sequence of

        FORTH ALSO  DEFINITIONS
        [DEF] : GET-FIND-3  [ANS] ['] FIND  [FIG] ['] FIND  [DEF] ['] FIND ;

  where the first wordlist to be searched via the search order are [ANS] and [FIG] and FORTH (in this order) and which may or may not yield different flavours of the FIND routine (i.e. different XTs)

  immediate code = [p4_bracket_def]

`CONTEXT?``( -- number )``` => `"EXTENSIONS"`

  GET-CONTEXT and count how many times it is in the order but the CONTEXT variable itself. The returned number is therefore minus one the occurences in the complete search-order. usage:

          ALSO EXTENSIONS CONTEXT? [IF] PREVIOUS [THEN]
          ALSO DEF' DEFAULT-ORDER
        : CONTEXT?
          0 LVALUE _count
          GET-ORDER 1- SWAP  LVALUE _context
          0 ?DO _context = IF 1 +TO _count THEN LOOP
          _count
        ;

  primitive code = [p4_context_Q]

`CASE-SENSITIVE-VOC``( -- )``` => `"EXTENSIONS"`

  accesses `CONTEXT` which is generally the last named `VOCABULARY` . sets a flag in the vocabulary-definition so that words are matched case-sensitive.

        example:
           VOCABULARY MY-VOC  MY-VOC CASE-SENSITIVE-VOC

  OBSOLETE! use `DEFS-ARE-CASE-SENSITIVE`

  primitive code = [p4_case_sensitive_voc]

`DEFS-ARE-CASE-SENSITIVE``( -- )``` => `"EXTENSIONS"`

  accesses `CURRENT` which is generally the last wordlist that the `DEFINITIONS` shall go in. sets there a flag in the vocabulary-definition so that words are matched case-sensitive.

        example:
           VOCABULARY MY-VOC  MY-VOC DEFINITIONS DEFS-ARE-CASE-SENSITIVE

  primitive code = [p4_defs_are_case_sensitive]

`DEFS-ARE-SEARCHED-ALSO``( -- )``` => `"EXTENSIONS"`

  binds `CONTEXT` with `CURRENT`. If the `CURRENT` `VOCABULARY` is in the search-order (later), then the `CONTEXT` vocabulary will be searched also. If the result of this word could lead into a recursive lookup with `FIND` it will throw `CURRENT_DELETED` and leave the `CURRENT` `VOCABULARY` unaltered.

        example:

  MY-VOC DEFINITIONS MY-VOC-PRIVATE DEFS-ARE-SEARCHED-ALSO

  primitive code = [p4_defs_are_searched_also]

## WITH-SPY

> kernel extension

`SPY-EXIT``( -- )``` => `"EXTENSIONS"`

  will unnest the current colon-word so it will actually return the word calling it. This can be found in the middle of a colon-sequence between `:` and `;`

  primitive code = [p4_spy_exit]

`;SPY``( -- )``` => `"EXTENSIONS"`

  compiles `((;))` which does `EXIT` the current colon-definition. It does then end compile-mode and returns to execute-mode. See `:` and `:NONAME`

  compiling word = [p4_spy_semicolon]

`SPY_ON``( -- )``` => `"EXTENSIONS"`

  change the runtime-code of `(NEST)` to call a special word that prints info to the screen whenever a colon word is entered. It will print the name and the current stack, and results in a kind of execution trace over `SPY' :`-colon nested words.

  primitive code = [p4_spy_on]

`SPY_OFF``( -- )``` => `"EXTENSIONS"`

  disable `SPY_ON` nest-trace.

  primitive code = [p4_spy_off]

## YOUR

> kernel extensions

`@>``( [name] -- value )``` => `"EXTENSIONS"`

  does fetch the value from the PFA of the named item, which may be about everything, including a `VARIABLE` , `VALUE` `LVALUE` , `LOCALS|` , `VAR` , `DEFER` , `DOER` , `DOES>` and more.

  compiling word = [p4_fetch_from]

`'>``( [name] -- xt )``` => `"EXTENSIONS"`

  get the execution-token, ie the CFA, of the word following. This word is fully state-smart while the ANSI standard words namely `'` and `[']` are not.

  compiling word = [p4_tick_from]

`INTO``( [name] -- pfa )``` => `"EXTENSIONS"`

  will return the parameter-field address of the following word. Unlike others, this word will also return the address of `LOCALS|` and local `LVALUE` - so in fact a `TO A` and `INTO A !` are the same. This word is most useful when calling C-exported function with a temporary local-VAR as a return-place argument - so the address of a local has to be given as an arg. Beware that you should not try to save the address anywhere else, since a local's address does always depend of the RP-depth - EXIT from a colon-word and the value may soon get overwritten. (see also `TO` )

  compiling word = [p4_into]

`.H2``( value -- )``` => `"EXTENSIONS"`

  print hexadecimal, but with per-byte 0-padding

          0x0     -> 00
          0xf     -> 0f
          0x12    -> 12
          0x123   -> 0123
          0x1234  -> 1234
          0x12345 -> 012345

  primitive code = [p4_dot_h2]

`HERE-WORD``( char "name<char>" -- )``` => `"EXTENSIONS"`

  a FIG-compatible WORD. Where ANSI says "skip leading delimiters" this one acts as "skip leading whitespace". And it will not return anything and have the string parsed to `HERE`

  primitive code = [p4_here_word]

## ZCHAR-EXT

> - zero-terminated C-like charstrings

`Z"``( [chars<">] -- z* )``` => `[FORTH]`

  scan the input to the next doublequote and create a buffer that holds the chars - return the address of that zero-terminated string-buffer, either `POCKET-PAD` or `ALLOT`ed into the dictionary.

  compiling word = [p4_z_quote]

`ZCOUNT``( z* -- z* len )``` => `[FORTH]`

  push length of z-string, additionally to the string addr itself.

        : ZSTRLEN ZCOUNT NIP ;

  (see libc strlen(3)) / compare with `COUNT` / `ZSTRLEN`

  primitive code = [p4_zcount]

`ZSTRLEN``( z* -- len )``` => `[FORTH]`

  push length of z-string.

        : ZSTRLEN ZCOUNT NIP ;

  (see libc strlen(3)) / compare with `ZMOVE` / `CMOVE`

  primitive code = [p4_zstrlen]

`ZMOVE``( zsrc* zdest* -- )``` => `[FORTH]`

  copy a zero terminated string (see libc strcpy(3)) / compare with `ZSTRLEN` / `COUNT`

  primitive code = [p4_zmove]

`ZPLACE``( addr* len zaddr* -- )``` => `[FORTH]`

  copy string and place as 0 terminated (see libc strncpy(3)) / see also `+ZPLACE` / `Z+PLACE`

  primitive code = [p4_zplace]

`+ZPLACE``( caddr* u zdest* -- )``` => `[FORTH]`

  Add the string defined by CADDR LEN to the zero terminated string at ZDEST - (for older scripts the `SYNONYM` named `APPENDZ` exists) (see libc strncat(3)) / compare with `ZPLACE` / `+PLACE`

  primitive code = [p4_appendz]

`S\"``( [backslashed-strings_<">] -- str cnt )``` => `[FORTH]`

  scan the following text to create a literal just like `S"` does, but backslashes can be used to escape special chars. The rules for the backslashes follow C literals, implemented techniques are \n \r \b \a \f \v \e \777 and all non-alnum chars represent themselves, esp. \" \' \ \? \! \% \( \) \[ \] \{ \} etcetera. most importantly the doublequote itself can be escaped. but be also informed that the usage of \' and \" is not portable as some systems preferred to map [\'] into ["]. Here I use the experimental addition to map [\q] to ["] and [\i] to [']

  compiling word = [p4_s_backslash_quote]

`C\"``( [backslashed-strings_<">] -- bstr* )``` => `[FORTH]`

  scan the following text to create a literal just like `C"` does, but backslashes can be used to escape special chars. The rules for the backslashes follow C literals, implemented techniques are \n \r \b \a \f \v \e \777 and all non-alnum chars represent themselves, esp. \" \' \ \? \! \% \( \) \[ \] \{ \} etcetera. most importantly the doublequote itself can be escaped. but be also informed that the usage of \' and \" is not portable as some systems preferred to map [\'] into ["]. Here I use the experimental addition to map [\q] to ["] and [\i] to [']

  compiling word = [p4_c_backslash_quote]

`Z\"``( [backslashed-strings_<">] -- zstr* )``` => `[FORTH]`

  scan the following text to create a literal just like `Z"` does, but backslashes can be used to escape special chars. The rules for the backslashes follow C literals, implemented techniques are \n \r \b \a \f \v \e \777 and all non-alnum chars represent themselves, esp. \" \' \ \? \! \% \( \) \[ \] \{ \} etcetera. most importantly the doublequote itself can be escaped but be also informed that the usage of \' and \" is not portable as some systems preferred to map [\'] into ["]. Here I use the experimental addition to map [\q] to ["] and [\i] to [']

  compiling word = [p4_z_backslash_quote]