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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 10646) characters.
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).
The full set of Unicode character attributes is not accessible
in this library.
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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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| 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 alphabetic Unicode characters (letters) that are not lower-case.
(In Unicode terms, this includes letters in upper and title cases,
as well as modifier letters and other letters.)
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| isAlpha :: Char -> Bool |
| Selects alphabetic Unicode characters (letters).
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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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| Case conversion
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| toUpper :: Char -> Char |
| Convert a letter to the corresponding upper-case letter, leaving any
other character unchanged. Any Unicode letter which has an upper-case
equivalent is transformed.
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| toLower :: Char -> Char |
| Convert a letter to the corresponding lower-case letter, leaving any
other character unchanged. Any Unicode letter which has a lower-case
equivalent is transformed.
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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 0.7 |
