Copyright	(c) Andrew Lelechenko 2015-2020
License	GPL-3
Maintainer	[email protected]
Stability	experimental
Safe Haskell	None
Language	Haskell2010

Data.FastDigits

Description

Convert an integer to digits and back. This library is both asymptotically (O(n^1.4) vs. O(n^2)) and practically (2x-40x for typical inputs) faster than Data.Digits.

Synopsis

digits :: Int -> Integer -> [Int]
undigits :: (Integral a, Integral b) => a -> [b] -> Integer
digitsUnsigned :: Word -> Natural -> [Word]

Documentation

digits Source #

Arguments

:: Int	The base to use
-> Integer	The number to convert
-> [Int]	Digits in reverse order

Return digits of a non-negative number in reverse order. Throw an error if number is negative or base is below 2.

digits 10 123 = [3, 2, 1]
digits 10 0   = []

undigits Source #

Arguments

:: (Integral a, Integral b)
=> a	The base to use
-> [b]	The list of digits to convert
-> Integer

Return an integer, built from given digits in reverse order. Condition 0 ≤ digit < base is not checked.

digitsUnsigned Source #

Arguments

:: Word	Precondition that base is ≥2 is not checked
-> Natural
-> [Word]

Return digits of a non-negative number in reverse order.