base-4.10.1.0: Basic libraries

Copyright(c) The University of Glasgow 2007
LicenseBSD-style (see the file libraries/base/LICENSE)
Maintainerlibraries@haskell.org
Stabilityexperimental
Portabilityportable
Safe HaskellTrustworthy
LanguageHaskell2010

Data.String

Contents

Description

The String type and associated operations.

Synopsis

Documentation

type String = [Char] #

A String is a list of characters. String constants in Haskell are values of type String.

class IsString a where #

Class for string-like datastructures; used by the overloaded string extension (-XOverloadedStrings in GHC).

Minimal complete definition

fromString

Methods

fromString :: String -> a #

Instances

(~) * a Char => IsString [a] #

(a ~ Char) context was introduced in 4.9.0.0

Since: 2.1

Methods

fromString :: String -> [a] #

IsString a => IsString (Identity a) # 

Methods

fromString :: String -> Identity a #

IsString a => IsString (Const * a b) #

Since: 4.9.0.0

Methods

fromString :: String -> Const * a b #

Functions on strings

lines :: String -> [String] #

lines breaks a string up into a list of strings at newline characters. The resulting strings do not contain newlines.

Note that after splitting the string at newline characters, the last part of the string is considered a line even if it doesn't end with a newline. For example,

lines "" == []
lines "\n" == [""]
lines "one" == ["one"]
lines "one\n" == ["one"]
lines "one\n\n" == ["one",""]
lines "one\ntwo" == ["one","two"]
lines "one\ntwo\n" == ["one","two"]

Thus lines s contains at least as many elements as newlines in s.

words :: String -> [String] #

words breaks a string up into a list of words, which were delimited by white space.

unlines :: [String] -> String #

unlines is an inverse operation to lines. It joins lines, after appending a terminating newline to each.

unwords :: [String] -> String #

unwords is an inverse operation to words. It joins words with separating spaces.