-- Hoogle documentation, generated by Haddock
-- See Hoogle, http://www.haskell.org/hoogle/
-- | Fast loops (for when GHC can't optimize forM_)
--
-- This package provides a convenient and fast alternative to the common
-- `forM_ [1..n]` idiom, which in many cases GHC cannot fuse to efficient
-- code.
--
-- See https:ghc.haskell.orgtracghcticket8763.
@package loop
@version 0.1.0
-- | This is for trying out loop alternatives.
--
-- Names and types are subjects to change.
module Control.Loop.Internal
-- | loop start end f: Loops from start to end
-- (inclusive), executing f on each iteration. Same as forM_
-- [start..end] f.
--
-- Uses succ inside, which does a bounds (overflow) check.
loop :: (Enum e, Eq e, Monad m) => e -> e -> (e -> m ()) -> m ()
-- | Like loop, but (sometimes) without bounds (overflow) check.
--
-- This circumvents the implementation of succ for the
-- Enum type and uses toEnum . (+ 1) . fromEnum
-- instead, so it will break on Enums that are not contiguous.
--
-- Note that some types (e.g. Word32) have bounds checks even for
-- toEnum.
unsafeLoop :: (Enum e, Eq e, Monad m) => e -> e -> (e -> m ()) -> m ()
-- | Like loop, but using Num instead.
--
-- It uses (+ 1) so for most integer types it has no bounds
-- (overflow) check.
numLoop :: (Num a, Eq a, Monad m) => a -> a -> (a -> m ()) -> m ()
-- | Provides a convenient and fast alternative to the common forM_
-- [1..n] idiom, which in many cases GHC cannot fuse to efficient
-- code.
--
-- Notes on fast iteration:
--
--
-- - For Int, (+1) is almost twice as fast as
-- succ because succ does an overflow check.
-- - For Int, you can get around that while still using
-- Enum using toEnum . (+ 1) . fromEnum.
-- - However, toEnum . (+ 1) . fromEnum is slower than
-- succ for Word32 on 64-bit machines since toEnum
-- has to check if the given Int exceeds 32 bits.
-- - Using (+1) from Num is always the fastest way, but
-- it gives no overflow checking.
-- - Using forLoop you can flexibly pick the way of increasing
-- the value that best fits your needs.
-- - The currently recommended replacement for forM_ [1..n] is
-- forLoop 1 (<= n) (+1).
--
module Control.Loop
-- | forLoop start cond inc f: A C-style for loop with starting
-- value, loop condition and incrementor.
forLoop :: Monad m => a -> (a -> Bool) -> (a -> a) -> (a -> m ()) -> m ()