ref: 48a34d1eb8df3def243689c0c5be2d5b3000a90c
dir: /src/MicroHs/List.hs/
-- Copyright 2023 Lennart Augustsson
-- See LICENSE file for full license.
module MicroHs.List where
import Data.List
-- Various useful list functions.
-- These are not really MicroHs specific.
------- List --------
elemBy :: (a -> a -> Bool) -> a -> [a] -> Bool
elemBy eq a = any (eq a)
-- A simple "quicksort" for now.
sortLE :: forall a . (a -> a -> Bool) -> [a] -> [a]
sortLE _ [] = []
sortLE le (x:xs) = sortLE le lt ++ (x : sortLE le ge)
where (ge, lt) = partition (le x) xs
showListS :: (a -> String) -> [a] -> String
showListS sa arg =
let
showRest as =
case as of
[] -> "]"
x : xs -> "," ++ sa x ++ showRest xs
in
case arg of
[] -> "[]"
a : as -> "[" ++ sa a ++ showRest as
anySame :: (Eq a) => [a] -> Bool
anySame = anySameBy (==)
anySameBy :: (a -> a -> Bool) -> [a] -> Bool
anySameBy _ [] = False
anySameBy eq (x:xs) = elemBy eq x xs || anySameBy eq xs
deleteAllBy :: forall a . (a -> a -> Bool) -> a -> [a] -> [a]
deleteAllBy _ _ [] = []
deleteAllBy eq x (y:ys) = if eq x y then deleteAllBy eq x ys else y : deleteAllBy eq x ys
deleteAllsBy :: forall a . (a -> a -> Bool) -> [a] -> [a] -> [a]
deleteAllsBy eq = foldl (flip (deleteAllBy eq))
padLeft :: Int -> String -> String
padLeft n s = replicate (n - length s) ' ' ++ s
partitionM :: Monad m => (a -> m Bool) -> [a] -> m ([a], [a])
partitionM _ [] = return ([], [])
partitionM p (x:xs) = do
b <- p x
(ts,fs) <- partitionM p xs
return $ if b then (x:ts, fs) else (ts, x:fs)
substString :: forall a . Eq a => [a] -> [a] -> [a] -> [a]
substString _ _ [] = []
substString from to xs@(c:cs) | Just rs <- stripPrefix from xs = to ++ substString from to rs
| otherwise = c : substString from to cs
showPairS :: forall a b . (a -> String) -> (b -> String) -> (a, b) -> String
showPairS sa sb (a, b) = "(" ++ sa a ++ "," ++ sb b ++ ")"
findCommonPrefix :: Eq a => [[a]] -> [a]
findCommonPrefix [] = []
findCommonPrefix ([] : _) = []
findCommonPrefix ((x:xs) : ys) | Just ys' <- mapM (f x) ys = x : findCommonPrefix (xs:ys')
| otherwise = []
where f a (b:bs) | a == b = Just bs
f _ _ = Nothing