Safe Haskell	Safe-Inferred
Language	Haskell2010

Data.Char

Contents

Characters and strings
Character classification
Subranges
Unicode general categories
Case conversion
Single digit characters
Numeric representations
String representations

Description

Synopsis

data Char
type String = [Char]
isControl :: Char -> Bool
isSpace :: Char -> Bool
isLower :: Char -> Bool
isUpper :: Char -> Bool
isAlpha :: Char -> Bool
isAlphaNum :: Char -> Bool
isPrint :: Char -> Bool
isDigit :: Char -> Bool
isOctDigit :: Char -> Bool
isHexDigit :: Char -> Bool
isLetter :: Char -> Bool
isMark :: Char -> Bool
isNumber :: Char -> Bool
isPunctuation :: Char -> Bool
isSymbol :: Char -> Bool
isSeparator :: Char -> Bool
isAscii :: Char -> Bool
isLatin1 :: Char -> Bool
isAsciiUpper :: Char -> Bool
isAsciiLower :: Char -> Bool
data GeneralCategory
- = UppercaseLetter
- | LowercaseLetter
- | TitlecaseLetter
- | ModifierLetter
- | OtherLetter
- | NonSpacingMark
- | SpacingCombiningMark
- | EnclosingMark
- | DecimalNumber
- | LetterNumber
- | OtherNumber
- | ConnectorPunctuation
- | DashPunctuation
- | OpenPunctuation
- | ClosePunctuation
- | InitialQuote
- | FinalQuote
- | OtherPunctuation
- | MathSymbol
- | CurrencySymbol
- | ModifierSymbol
- | OtherSymbol
- | Space
- | LineSeparator
- | ParagraphSeparator
- | Control
- | Format
- | Surrogate
- | PrivateUse
- | NotAssigned
generalCategory :: Char -> GeneralCategory
toUpper :: Char -> Char
toLower :: Char -> Char
toTitle :: Char -> Char
digitToInt :: Char -> Int
intToDigit :: Int -> Char
ord :: Char -> Int
chr :: Int -> Char
showLitChar :: Char -> ShowS
lexLitChar :: ReadS String
readLitChar :: ReadS Char

Characters and strings

data Char #

The character type Char is an enumeration whose values represent Unicode (or equivalently ISO/IEC 10646) characters (see http://www.unicode.org/ for details). This set extends the ISO 8859-1 (Latin-1) character set (the first 256 charachers), which is itself an extension of the ASCII character set (the first 128 characters). A character literal in Haskell has type Char. To convert a Char to or from the corresponding Int value defined by Unicode, use Prelude.toEnum and Prelude.fromEnum from the Prelude.Enum class respectively (or equivalently ord and chr).

Instances

Instances details

Bounded Char #
Instance details Defined in Data.Enum Methods minBound :: Char # maxBound :: Char #
Enum Char #
Instance details Defined in Data.Enum Methods succ :: Char -> Char # pred :: Char -> Char # toEnum :: Int -> Char # fromEnum :: Char -> Int # enumFrom :: Char -> [Char] # enumFromThen :: Char -> Char -> [Char] # enumFromTo :: Char -> Char -> [Char] # enumFromThenTo :: Char -> Char -> Char -> [Char] #
Eq Char #
Instance details Defined in Data.Eq Methods (==) :: Char -> Char -> Bool # (/=) :: Char -> Char -> Bool #
Ix Char #
Instance details Defined in Data.Ix Methods range :: (Char, Char) -> [Char] # index :: (Char, Char) -> Char -> Int # inRange :: (Char, Char) -> Char -> Bool # rangeSize :: (Char, Char) -> Int #
Ord Char #
Instance details Defined in Data.Ord Methods compare :: Char -> Char -> Ordering # (<) :: Char -> Char -> Bool # (<=) :: Char -> Char -> Bool # (>=) :: Char -> Char -> Bool # (>) :: Char -> Char -> Bool # max :: Char -> Char -> Char # min :: Char -> Char -> Char #
Storable Char #
Instance details Defined in Foreign.Storable Methods sizeOf :: Char -> Int # alignment :: Char -> Int # peekElemOff :: Ptr Char -> Int -> IO Char # pokeElemOff :: Ptr Char -> Int -> Char -> IO () # peekByteOff :: Ptr b -> Int -> IO Char # pokeByteOff :: Ptr b -> Int -> Char -> IO () # peek :: Ptr Char -> IO Char # poke :: Ptr Char -> Char -> IO () #
Read Char #
Instance details Defined in Text.Read Methods readsPrec :: Int -> ReadS Char # readList :: ReadS [Char] #
Show Char #
Instance details Defined in Text.Show Methods showsPrec :: Int -> Char -> ShowS # show :: Char -> String # showList :: [Char] -> ShowS #

type String = [Char] #

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

Character classification

Unicode characters are divided into letters, numbers, marks, punctuation, symbols, separators (including spaces) and others (including control characters).

isControl :: Char -> Bool #

Selects control characters, which are the non-printing characters of the Latin-1 subset of Unicode.

isSpace :: Char -> Bool #

Returns True for any Unicode space character, and the control characters \t, \n, \r, \f, \v.

isLower :: Char -> Bool #

Selects lower-case alphabetic Unicode characters (letters).

isUpper :: Char -> Bool #

Selects upper-case or title-case alphabetic Unicode characters (letters). Title case is used by a small number of letter ligatures like the single-character form of Lj.

isAlpha :: Char -> Bool #

Selects alphabetic Unicode characters (lower-case, upper-case and title-case letters, plus letters of caseless scripts and modifiers letters). This function is equivalent to Data.Char.isLetter.

isAlphaNum :: Char -> Bool #

Selects alphabetic or numeric digit Unicode characters.

Note that numeric digits outside the ASCII range are selected by this function but not by isDigit. Such digits may be part of identifiers but are not used by the printer and reader to represent numbers.

isPrint :: Char -> Bool #

Selects printable Unicode characters (letters, numbers, marks, punctuation, symbols and spaces)

isDigit :: Char -> Bool #

Selects ASCII digits, i.e. ’0’..’9’.

isOctDigit :: Char -> Bool #

Selects ASCII octal digits, i.e. ’0’..’7’.

isHexDigit :: Char -> Bool #

Selects ASCII hexadecimal digits, i.e. ’0’..’9’, ’a’..’f’, ’A’..’F’.

isLetter :: Char -> Bool #

Selects alphabetic Unicode characters (lower-case, upper-case and title-case letters, plus letters of caseless scripts and modifiers letters). This function is equivalent to Data.Char.isAlpha.

isMark :: Char -> Bool #

Selects Unicode mark characters, e.g. accents and the like, which combine with preceding letters.

isNumber :: Char -> Bool #

Selects Unicode numeric characters, including digits from various scripts, Roman numerals, etc.

isPunctuation :: Char -> Bool #

Selects Unicode punctuation characters, including various kinds of connectors, brackets and quotes.

isSymbol :: Char -> Bool #

Selects Unicode symbol characters, including mathematical and currency symbols.

isSeparator :: Char -> Bool #

Selects Unicode space and separator characters.

Subranges

isAscii :: Char -> Bool #

Selects the first 128 characters of the Unicode character set, corresponding to the ASCII character set.

isLatin1 :: Char -> Bool #

Selects the first 256 characters of the Unicode character set, corresponding to the ISO 8859-1 (Latin-1) character set.

isAsciiUpper :: Char -> Bool #

Selects ASCII upper-case letters, i.e. characters satisfying both isAscii and isUpper.

isAsciiLower :: Char -> Bool #

Selects ASCII lower-case letters, i.e. characters satisfying both isAscii and isLower.

Unicode general categories

data GeneralCategory #

Unicode General Categories (column 2 of the UnicodeData table) in the order they are listed in the Unicode standard.

Constructors

UppercaseLetter	Lu: Letter, Uppercase
LowercaseLetter	Ll: Letter, Lowercase
TitlecaseLetter	Lt: Letter, Titlecase
ModifierLetter	Lm: Letter, Modifier
OtherLetter	Lo: Letter, Other
NonSpacingMark	Mn: Mark, Non-Spacing
SpacingCombiningMark	Mc: Mark, Spacing Combining
EnclosingMark	Me: Mark, Enclosing
DecimalNumber	Nd: Number, Decimal
LetterNumber	Nl: Number, Letter
OtherNumber	No: Number, Other
ConnectorPunctuation	Pc: Punctuation, Connector
DashPunctuation	Pd: Punctuation, Dash
OpenPunctuation	Ps: Punctuation, Open
ClosePunctuation	Pe: Punctuation, Close
InitialQuote	Pi: Punctuation, Initial quote
FinalQuote	Pf: Punctuation, Final quote
OtherPunctuation	Po: Punctuation, Other
MathSymbol	Sm: Symbol, Math
CurrencySymbol	Sc: Symbol, Currency
ModifierSymbol	Sk: Symbol, Modifier
OtherSymbol	So: Symbol, Other
Space	Zs: Separator, Space
LineSeparator	Zl: Separator, Line
ParagraphSeparator	Zp: Separator, Paragraph
Control	Cc: Other, Control
Format	Cf: Other, Format
Surrogate	Cs: Other, Surrogate
PrivateUse	Co: Other, Private Use
NotAssigned	Cn: Other, Not Assigned

Instances

Instances details

Bounded GeneralCategory #
Instance details Defined in Data.Char Methods minBound :: GeneralCategory # maxBound :: GeneralCategory #
Enum GeneralCategory #
Instance details Defined in Data.Char Methods succ :: GeneralCategory -> GeneralCategory # pred :: GeneralCategory -> GeneralCategory # toEnum :: Int -> GeneralCategory # fromEnum :: GeneralCategory -> Int # enumFrom :: GeneralCategory -> [GeneralCategory] # enumFromThen :: GeneralCategory -> GeneralCategory -> [GeneralCategory] # enumFromTo :: GeneralCategory -> GeneralCategory -> [GeneralCategory] # enumFromThenTo :: GeneralCategory -> GeneralCategory -> GeneralCategory -> [GeneralCategory] #
Eq GeneralCategory #
Instance details Defined in Data.Char Methods (==) :: GeneralCategory -> GeneralCategory -> Bool # (/=) :: GeneralCategory -> GeneralCategory -> Bool #
Ix GeneralCategory #
Instance details Defined in Data.Char Methods range :: (GeneralCategory, GeneralCategory) -> [GeneralCategory] # index :: (GeneralCategory, GeneralCategory) -> GeneralCategory -> Int # inRange :: (GeneralCategory, GeneralCategory) -> GeneralCategory -> Bool # rangeSize :: (GeneralCategory, GeneralCategory) -> Int #
Ord GeneralCategory #
Instance details Defined in Data.Char Methods compare :: GeneralCategory -> GeneralCategory -> Ordering # (<) :: GeneralCategory -> GeneralCategory -> Bool # (<=) :: GeneralCategory -> GeneralCategory -> Bool # (>=) :: GeneralCategory -> GeneralCategory -> Bool # (>) :: GeneralCategory -> GeneralCategory -> Bool # max :: GeneralCategory -> GeneralCategory -> GeneralCategory # min :: GeneralCategory -> GeneralCategory -> GeneralCategory #
Read GeneralCategory #
Instance details Defined in Data.Char Methods readsPrec :: Int -> ReadS GeneralCategory # readList :: ReadS [GeneralCategory] #
Show GeneralCategory #
Instance details Defined in Data.Char Methods showsPrec :: Int -> GeneralCategory -> ShowS # show :: GeneralCategory -> String # showList :: [GeneralCategory] -> ShowS #

generalCategory :: Char -> GeneralCategory #

The Unicode general category of the character.

Case conversion

toUpper :: Char -> Char #

Convert a letter to the corresponding upper-case letter, if any. Any other character is returned un- changed.

toLower :: Char -> Char #

Convert a letter to the corresponding lower-case letter, if any. Any other character is returned un- changed.

toTitle :: Char -> Char #

Convert a letter to the corresponding title-case or upper-case letter, if any. (Title case differs from upper case only for a small number of ligature letters.) Any other character is returned unchanged.

Single digit characters

digitToInt :: Char -> Int #

Convert a single digit Char to the corresponding Int. This function fails unless its argument satisfies isHexDigit, but recognises both upper and lower-case hexadecimal digits (i.e. ’0’..’9’, ’a’..’f’, ’A’..’F’).

intToDigit :: Int -> Char #

Convert an Int in the range 0..15 to the corresponding single digit Char. This function fails on other inputs, and generates lower-case hexadecimal digits

Numeric representations

ord :: Char -> Int #

The Prelude.fromEnum method restricted to the type Data.Char.Char

chr :: Int -> Char #

The Prelude.toEnum method restricted to the type Data.Char.Char.

String representations

showLitChar :: Char -> ShowS #

Convert a character to a string using only printable characters, using Haskell source-language escape conventions. For example:

showLitChar ’n’ s = "\n" ++ s

lexLitChar :: ReadS String #

Read a string representation of a character, using Haskell source-language escape conventions. For example:

lexLitChar "\nHello" = [("\n", Hello)]

readLitChar :: ReadS Char #

Read a string representation of a character, using Haskell source-language escape conventions, and convert it to the character that it encodes. For example:

readLitChar "\nHello" = [(’n’, Hello)]