rio-0.1.22.0: A standard library for Haskell

Safe Haskell | Safe-Inferred
Language | Haskell2010

RIO.Char.Partial

Contents

- Single digit characters
- Numeric representations

Description

Unicode `Char` partial functions. Import as:

    import qualified RIO.Char.Partial as C'

Synopsis

- digitToInt :: Char -> Int
- intToDigit :: Int -> Char
- chr :: Int -> Char

# 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 (that is, `'0'`..`'9'`, `'a'`..`'f'`, `'A'`..`'F'`).

#### Examples

Expand

Characters `'0'` through `'9'` are converted properly to `0..9`:

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

Both upper- and lower-case `'A'` through `'F'` are converted as well, to `10..15`.

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

Anything else throws an exception:

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

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

chr :: Int -> Char #

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