Char

haskell98-2.0.0.3: Compatibility with Haskell 98

Safe Haskell | Safe
Language | Haskell98

Char

Synopsis

- isAscii :: Char -> Bool
- isLatin1 :: Char -> Bool
- isControl :: Char -> Bool
- isPrint :: Char -> Bool
- isSpace :: Char -> Bool
- isUpper :: Char -> Bool
- isLower :: Char -> Bool
- isAlpha :: Char -> Bool
- isDigit :: Char -> Bool
- isOctDigit :: Char -> Bool
- isHexDigit :: Char -> Bool
- isAlphaNum :: Char -> Bool
- digitToInt :: Char -> Int
- intToDigit :: Int -> Char
- toUpper :: Char -> Char
- toLower :: Char -> Char
- ord :: Char -> Int
- chr :: Int -> Char
- readLitChar :: ReadS Char
- showLitChar :: Char -> ShowS
- lexLitChar :: ReadS String
- data Char :: *
- type String = [Char]

# Documentation

isAscii :: Char -> Bool Source

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

isLatin1 :: Char -> Bool Source

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

isControl :: Char -> Bool Source

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

isPrint :: Char -> Bool Source

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

isSpace :: Char -> Bool Source

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

isUpper :: Char -> Bool Source

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.

isLower :: Char -> Bool Source

Selects lower-case alphabetic Unicode characters (letters).

isAlpha :: Char -> Bool Source

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`.

isDigit :: Char -> Bool Source

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

isOctDigit :: Char -> Bool Source

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

isHexDigit :: Char -> Bool Source

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

isAlphaNum :: Char -> Bool Source

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.

digitToInt :: Char -> Int Source

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 Source

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.

toUpper :: Char -> Char Source

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

toLower :: Char -> Char Source

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

ord :: Char -> Int Source

The `fromEnum` method restricted to the type `Char`.

chr :: Int -> Char Source

The `toEnum` method restricted to the type `Char`.

readLitChar :: ReadS Char Source

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")]

showLitChar :: Char -> ShowS Source

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 Source

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

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

data Char :: *

Instances

Bounded Char |
Enum Char |
Eq Char |
Ord Char |
Read Char |
Show Char |
Ix Char |
Storable Char |
Random Char |

type String = [Char] Source

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