Safe Haskell	None
Language	Haskell2010

Patterns

Description

This module describes the patterns supported by Relapse.

It also contains some simple functions for the map of references that a Relapse grammar consists of.

Finally it also contains some very simple pattern functions.

Synopsis

Documentation

Pattern recursively describes a Relapse Pattern.

Instances

Eq Pattern #
Methods (==) :: Pattern -> Pattern -> Bool # (/=) :: Pattern -> Pattern -> Bool #
Ord Pattern #
Methods compare :: Pattern -> Pattern -> Ordering # (<) :: Pattern -> Pattern -> Bool # (<=) :: Pattern -> Pattern -> Bool # (>) :: Pattern -> Pattern -> Bool # (>=) :: Pattern -> Pattern -> Bool # max :: Pattern -> Pattern -> Pattern # min :: Pattern -> Pattern -> Pattern #
Show Pattern #
Methods showsPrec :: Int -> Pattern -> ShowS # show :: Pattern -> String # showList :: [Pattern] -> ShowS #

data Refs #

Refs is a map from reference name to pattern and describes a relapse grammar.

Instances

Eq Refs #
Methods (==) :: Refs -> Refs -> Bool # (/=) :: Refs -> Refs -> Bool #
Show Refs #
Methods showsPrec :: Int -> Refs -> ShowS # show :: Refs -> String # showList :: [Refs] -> ShowS #

emptyRef returns an empty reference map.

union returns the union of two reference maps.

newRef returns a new reference map given a single pattern and its reference name.

reverseLookupRef returns the reference name for a given pattern.

lookupRef looks up a pattern in the reference map, given a reference name.

hasRecursion returns whether an relapse grammar has any recursion, starting from the "main" reference.

The nullable function returns whether a pattern is nullable. This means that the pattern matches the empty string.

unescapable is used for short circuiting. A part of the tree can be skipped if all patterns are unescapable.