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| Data.Char | | Portability | portable | | Stability | stable | | Maintainer | libraries@haskell.org |
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| Description |
| The Char type and associated operations.
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| Synopsis |
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| Documentation |
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| 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 toEnum and fromEnum from the
Enum class respectively (or equivalently ord and chr).
|  Instances | |
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| type String = [Char] |
| A String is a list of characters. String constants in Haskell are values
of type String.
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| Character classification
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| Unicode characters are divided into letters, numbers, marks,
punctuation, symbols, separators (including spaces) and others
(including control characters).
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| isControl :: Char -> Bool |
| Selects control characters, which are the non-printing characters of
the Latin-1 subset of Unicode.
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| isSpace :: Char -> Bool |
| Selects white-space characters in the Latin-1 range.
(In Unicode terms, this includes spaces and some control characters.)
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| isLower :: Char -> Bool |
| Selects lower-case alphabetic Unicode characters (letters).
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| 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.
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| 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 isLetter.
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| 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.
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| isPrint :: Char -> Bool |
| Selects printable Unicode characters
(letters, numbers, marks, punctuation, symbols and spaces).
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| isDigit :: Char -> Bool |
| Selects ASCII digits, i.e. '0'..'9'.
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| isOctDigit :: Char -> Bool |
| Selects ASCII octal digits, i.e. '0'..'7'.
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| isHexDigit :: Char -> Bool |
| Selects ASCII hexadecimal digits,
i.e. '0'..'9', 'a'..'f', 'A'..'F'.
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| 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 isAlpha.
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| isMark :: Char -> Bool |
| Selects Unicode mark characters, e.g. accents and the like, which
combine with preceding letters.
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| isNumber :: Char -> Bool |
| Selects Unicode numeric characters, including digits from various
scripts, Roman numerals, etc.
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| isPunctuation :: Char -> Bool |
| Selects Unicode punctuation characters, including various kinds
of connectors, brackets and quotes.
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| isSymbol :: Char -> Bool |
| Selects Unicode symbol characters, including mathematical and
currency symbols.
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| isSeparator :: Char -> Bool |
| Selects Unicode space and separator characters.
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| Subranges
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| isAscii :: Char -> Bool |
| Selects the first 128 characters of the Unicode character set,
corresponding to the ASCII character set.
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| isLatin1 :: Char -> Bool |
| Selects the first 256 characters of the Unicode character set,
corresponding to the ISO 8859-1 (Latin-1) character set.
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| isAsciiUpper :: Char -> Bool |
| Selects ASCII upper-case letters,
i.e. characters satisfying both isAscii and isUpper.
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| isAsciiLower :: Char -> Bool |
| Selects ASCII lower-case letters,
i.e. characters satisfying both isAscii and isLower.
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| Unicode general categories
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| 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
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| | Instances | |
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| generalCategory :: Char -> GeneralCategory |
| The Unicode general category of the character.
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| Case conversion
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| toUpper :: Char -> Char |
| Convert a letter to the corresponding upper-case letter, if any.
Any other character is returned unchanged.
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| toLower :: Char -> Char |
| Convert a letter to the corresponding lower-case letter, if any.
Any other character is returned unchanged.
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| 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.
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| Single digit characters
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| 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').
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| 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.
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| Numeric representations
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| ord :: Char -> Int |
| The fromEnum method restricted to the type Char.
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| chr :: Int -> Char |
| The toEnum method restricted to the type Char.
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| String representations
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| 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
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| lexLitChar :: ReadS String |
Read a string representation of a character, using Haskell
source-language escape conventions. For example:
lexLitChar "\\nHello" = [("\\n", "Hello")]
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| 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")]
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| Produced by Haddock version 0.8 |
