mirror of
https://github.com/xmonad/xmonad-contrib.git
synced 2025-05-19 03:20:21 -07:00
71 lines
2.1 KiB
Haskell
71 lines
2.1 KiB
Haskell
{-# LANGUAGE BangPatterns #-}
|
|
--------------------------------------------------------------------
|
|
-- |
|
|
-- Module : XMonad.Prelude
|
|
-- Description : Utility functions and re-exports.
|
|
-- Copyright : slotThe <soliditsallgood@mailbox.org>
|
|
-- License : BSD3-style (see LICENSE)
|
|
--
|
|
-- Maintainer : slotThe <soliditsallgood@mailbox.org>
|
|
--
|
|
-- Utility functions and re-exports for a more ergonomic developing
|
|
-- experience. Users themselves will not find much use here.
|
|
--
|
|
--------------------------------------------------------------------
|
|
module XMonad.Prelude (
|
|
module Exports,
|
|
fi,
|
|
chunksOf,
|
|
(.:),
|
|
(!?),
|
|
NonEmpty((:|)),
|
|
notEmpty,
|
|
) where
|
|
|
|
import Control.Applicative as Exports
|
|
import Control.Monad as Exports
|
|
import Data.Bool as Exports
|
|
import Data.Char as Exports
|
|
import Data.Foldable as Exports
|
|
import Data.Function as Exports
|
|
import Data.Functor as Exports
|
|
import Data.List as Exports
|
|
import Data.Maybe as Exports
|
|
import Data.Monoid as Exports
|
|
import Data.Traversable as Exports
|
|
|
|
import Data.List.NonEmpty (NonEmpty((:|)))
|
|
import GHC.Stack
|
|
|
|
-- | Short for 'fromIntegral'.
|
|
fi :: (Integral a, Num b) => a -> b
|
|
fi = fromIntegral
|
|
|
|
-- | Given a maximum length, splits a list into sublists
|
|
--
|
|
-- >>> chunksOf 5 (take 30 $ repeat 'a')
|
|
-- ["aaaaa","aaaaa","aaaaa","aaaaa","aaaaa","aaaaa"]
|
|
chunksOf :: Int -> [a] -> [[a]]
|
|
chunksOf _ [] = []
|
|
chunksOf i xs = chunk : chunksOf i rest
|
|
where !(chunk, rest) = splitAt i xs
|
|
|
|
-- | Safe version of '(!!)'.
|
|
(!?) :: [a] -> Int -> Maybe a
|
|
(!?) xs n | n < 0 = Nothing
|
|
| otherwise = listToMaybe $ drop n xs
|
|
|
|
-- | Multivariant composition.
|
|
--
|
|
-- > f .: g ≡ (f .) . g ≡ \c d -> f (g c d)
|
|
(.:) :: (a -> b) -> (c -> d -> a) -> c -> d -> b
|
|
(.:) = (.) . (.)
|
|
|
|
-- | 'Data.List.NonEmpty.fromList' with a better error message. Useful to
|
|
-- silence GHC's Pattern match(es) are non-exhaustive warning in places where
|
|
-- the programmer knows it's always non-empty, but it's infeasible to express
|
|
-- that in the type system.
|
|
notEmpty :: HasCallStack => [a] -> NonEmpty a
|
|
notEmpty [] = error "unexpected empty list"
|
|
notEmpty (x:xs) = x :| xs
|