Safe Haskell	None
Language	Haskell2010

Text.Scanf

Contents

Description

Dead simple and type-safe scanf/printf.

Synopsis

Main definitions

Parse a string according to a format string.

scanf [fmt|Hello %s|] "Hello world!" :: Maybe (Format :+ ())
  = ("world!" :+ ())

Print a string according to a format string.

printf [fmt|Hello %s|] ("everyone!" :+ ())
  = "Hello everyone!"

data a :+ b infixr 1 #

A pretty pair type to build lists with values of different types. Remember to close lists with ().

3 :+ "14" :+ () :: Int :+ Format :+ ()

Constructors

a :+ b infixr 1

Instances

(Eq a, Eq b) => Eq (a :+ b) #
Instance details Defined in Text.Scanf.Internal Methods (==) :: (a :+ b) -> (a :+ b) -> Bool # (/=) :: (a :+ b) -> (a :+ b) -> Bool #
(Ord a, Ord b) => Ord (a :+ b) #
Instance details Defined in Text.Scanf.Internal Methods compare :: (a :+ b) -> (a :+ b) -> Ordering # (<) :: (a :+ b) -> (a :+ b) -> Bool # (<=) :: (a :+ b) -> (a :+ b) -> Bool # (>) :: (a :+ b) -> (a :+ b) -> Bool # (>=) :: (a :+ b) -> (a :+ b) -> Bool # max :: (a :+ b) -> (a :+ b) -> a :+ b # min :: (a :+ b) -> (a :+ b) -> a :+ b #
(Show a, Show b) => Show (a :+ b) #
Instance details Defined in Text.Scanf.Internal Methods showsPrec :: Int -> (a :+ b) -> ShowS # show :: (a :+ b) -> String # showList :: [a :+ b] -> ShowS #

Parse a typed Format string.

The following conversion strings are supported:

N.B.: in scanf, spaces in the format string match any number of whitespace character until the next nonspace character.

[fmt|%d lazy %s and %d strict %s|]
  :: Format (Int :+ Format :+ Int :+ Format :+ ())

Construct a format string. This is an alternative to fmt that doesn't rely on Template Haskell.

The components of a format string are composed using (.) (function composition) and (%) (wrapper for constant strings).

fmt_ (int . " lazy " % string . " and " % int . " strict " % string)
  :: Format (Int :+ Format :+ Int :+ Format :+ ())

data Format t #

Typed scanf/printf format strings. They can be built using the fmt quasiquote or with the fmt_ function and format combinators.

Instances

Show (Format t) #
Instance details Defined in Text.Scanf.Internal Methods showsPrec :: Int -> Format t -> ShowS # show :: Format t -> String # showList :: [Format t] -> ShowS #

Format constructors

(%) :: String -> (Format t -> Format q) -> Format t -> Format q infixr 9 #

Append a constant string to a format string component.

N.B.: in scanf, spaces in the format string match any number of whitespace character until the next nonspace character.

Format an Integer.

Format an Int.

Format a Double.

Format a Format.

Format a Format.