The character typeChar is an enumeration whose values representUnicode (or equivalently ISO/IEC 10646) code points (i.e. characters, seehttp://www.unicode.org/ for details). This set extends the ISO 8859-1(Latin-1) character set (the first 256 characters), which is itself an extensionof the ASCII character set (the first 128 characters). A character literal inHaskell has typeChar.

To convert aChar to or from the correspondingInt value definedby Unicode, usetoEnum andfromEnum from theEnum class respectively (or equivalentlyord andchr).

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

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

Selects lower-case alphabetic Unicode characters (letters).

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 ofLj.

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

Selects alphabetic or numeric Unicode characters.

Note that numeric digits outside the ASCII range, as well as numeric characters which aren't digits, are selected by this function but not byisDigit. Such characters may be part of identifiers but are not used by the printer and reader to represent numbers.

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

Selects ASCII digits, i.e.'0'..'9'.

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

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

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

This function returnsTrue if its argument has one of the followingGeneralCategorys, orFalse otherwise:

• UppercaseLetter
• LowercaseLetter
• TitlecaseLetter
• ModifierLetter
• OtherLetter

These classes are defined in theUnicode Character Database, part of the Unicode standard. The same document defines what is and is not a "Letter".

Examples

>>>isLetter 'a'True>>>isLetter 'A'True>>>isLetter 'λ'True>>>isLetter '0'False>>>isLetter '%'False>>>isLetter '♥'False>>>isLetter '\31'False

>>>let chars = [(chr 0)..]>>>let letters = map isLetter chars>>>let alphas = map isAlpha chars>>>letters == alphasTrue

Selects Unicode mark characters, for example accents and the like, which combine with preceding characters.

This function returnsTrue if its argument has one of the followingGeneralCategorys, orFalse otherwise:

• NonSpacingMark
• SpacingCombiningMark
• EnclosingMark

These classes are defined in theUnicode Character Database, part of the Unicode standard. The same document defines what is and is not a "Mark".

Examples

>>>isMark 'a'False>>>isMark '0'False

>>>map isMark "ò"[False,True]

>>>isMark '✓'False

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

This function returnsTrue if its argument has one of the followingGeneralCategorys, orFalse otherwise:

• DecimalNumber
• LetterNumber
• OtherNumber

These classes are defined in theUnicode Character Database, part of the Unicode standard. The same document defines what is and is not a "Number".

Examples

>>>isNumber 'a'False>>>isNumber '%'False>>>isNumber '3'True

>>>and $ map isNumber ['0'..'9']True

>>>isNumber 'Ⅸ'True

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

This function returnsTrue if its argument has one of the followingGeneralCategorys, orFalse otherwise:

• ConnectorPunctuation
• DashPunctuation
• OpenPunctuation
• ClosePunctuation
• InitialQuote
• FinalQuote
• OtherPunctuation

These classes are defined in theUnicode Character Database, part of the Unicode standard. The same document defines what is and is not a "Punctuation".

Examples

>>>isPunctuation 'a'False>>>isPunctuation '7'False>>>isPunctuation '♥'False>>>isPunctuation '"'True>>>isPunctuation '?'True>>>isPunctuation '—'True

Selects Unicode symbol characters, including mathematical and currency symbols.

This function returnsTrue if its argument has one of the followingGeneralCategorys, orFalse otherwise:

• MathSymbol
• CurrencySymbol
• ModifierSymbol
• OtherSymbol

These classes are defined in theUnicode Character Database, part of the Unicode standard. The same document defines what is and is not a "Symbol".

Examples

>>>isSymbol 'a'False>>>isSymbol '6'False>>>isSymbol '='True

>>>isSymbol '+'True>>>isSymbol '-'False

Selects Unicode space and separator characters.

This function returnsTrue if its argument has one of the followingGeneralCategorys, orFalse otherwise:

• Space
• LineSeparator
• ParagraphSeparator

These classes are defined in theUnicode Character Database, part of the Unicode standard. The same document defines what is and is not a "Separator".

Examples

>>>isSeparator 'a'False>>>isSeparator '6'False>>>isSeparator ' 'True

>>>isSeparator '\n'False>>>isSeparator '\t'False

>>>isSeparator '\160'True

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

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

Selects ASCII upper-case letters, i.e. characters satisfying bothisAscii andisUpper.

Selects ASCII lower-case letters, i.e. characters satisfying bothisAscii andisLower.

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

Examples

>>>:t OtherLetterOtherLetter :: GeneralCategory

>>>UppercaseLetter == UppercaseLetterTrue>>>UppercaseLetter == LowercaseLetterFalse

>>>NonSpacingMark <= MathSymbolTrue

>>>enumFromTo ModifierLetter SpacingCombiningMark[ModifierLetter,OtherLetter,NonSpacingMark,SpacingCombiningMark]

>>>read "DashPunctuation" :: GeneralCategoryDashPunctuation>>>read "17" :: GeneralCategory*** Exception: Prelude.read: no parse

>>>show EnclosingMark"EnclosingMark"

>>>minBound :: GeneralCategoryUppercaseLetter>>>maxBound :: GeneralCategoryNotAssigned

>>>import Data.Ix ( index )>>>index (OtherLetter,Control) FinalQuote12>>>index (OtherLetter,Control) Format*** Exception: Error in array index

Constructors

The Unicode general category of the character. This relies on theEnum instance ofGeneralCategory, which must remain in the same order as the categories are presented in the Unicode standard.

Examples

>>>generalCategory 'a'LowercaseLetter>>>generalCategory 'A'UppercaseLetter>>>generalCategory '0'DecimalNumber>>>generalCategory '%'OtherPunctuation>>>generalCategory '♥'OtherSymbol>>>generalCategory '\31'Control>>>generalCategory ' 'Space

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

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

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.

Convert a single digitChar to the correspondingInt. This function fails unless its argument satisfiesisHexDigit, but recognises both upper- and lower-case hexadecimal digits (that is,'0'..'9','a'..'f','A'..'F').

Examples

>>>map digitToInt ['0'..'9'][0,1,2,3,4,5,6,7,8,9]

>>>map digitToInt ['a'..'f'][10,11,12,13,14,15]>>>map digitToInt ['A'..'F'][10,11,12,13,14,15]

>>>digitToInt 'G'*** Exception: Char.digitToInt: not a digit 'G'>>>digitToInt '♥'*** Exception: Char.digitToInt: not a digit '\9829'

Convert anInt in the range0..15 to the corresponding single digitChar. This function fails on other inputs, and generates lower-case hexadecimal digits.

ThefromEnum method restricted to the typeChar.

ThetoEnum method restricted to the typeChar.

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

showLitChar '\n' s  =  "\\n" ++ s

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

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

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")]