{- Copyright (C) 2018 Dr. Alistair Ward This file is part of BishBosh. BishBosh is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. BishBosh is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with BishBosh. If not, see <http://www.gnu.org/licenses/>. -} {- | [@AUTHOR@] Dr. Alistair Ward [@DESCRIPTION@] Arbitrary operations for numeric types. -} module BishBosh.Data.Integral( -- * Functions stringToUnsignedDecimal ) where import qualified Data.Char import qualified Data.List {- | * N.B. much faster than the instance of 'Read' for the integral type. TODO: compare with 'Numeric.readDec'. * N.B. ignores any leading zeroes. * CAVEAT: intolerant to any white-space or a leading sign-character; 'Data.Char.digitToInt' throws an exception if it receives a character which isn't a digit. -} stringToUnsignedDecimal :: Num i => String -> i stringToUnsignedDecimal :: String -> i stringToUnsignedDecimal = Int -> i forall a b. (Integral a, Num b) => a -> b fromIntegral (Int -> i) -> (String -> Int) -> String -> i forall b c a. (b -> c) -> (a -> b) -> a -> c . (Int -> Char -> Int) -> Int -> String -> Int forall (t :: * -> *) b a. Foldable t => (b -> a -> b) -> b -> t a -> b Data.List.foldl' (\Int i -> (Int -> Int -> Int forall a. Num a => a -> a -> a + Int 10 Int -> Int -> Int forall a. Num a => a -> a -> a * Int i) (Int -> Int) -> (Char -> Int) -> Char -> Int forall b c a. (b -> c) -> (a -> b) -> a -> c . Char -> Int Data.Char.digitToInt) Int 0