git.iko.soy/streamly
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streamly/src/Streamly/Internal/Data/Maybe/Strict.hs
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1-- |
2-- Module : Streamly.Internal.Data.Maybe.Strict
3-- Copyright : (c) 2019 Composewell Technologies
4-- (c) 2013 Gabriel Gonzalez
5-- License : BSD3
6-- Maintainer : streamly@composewell.com
7-- Stability : experimental
8-- Portability : GHC
9--
10-- | Strict data types to be used as accumulator for strict left folds and
11-- scans. For more comprehensive strict data types see
12-- https://hackage.haskell.org/package/strict-base-types . The names have been
13-- suffixed by a prime so that programmers can easily distinguish the strict
14-- versions from the lazy ones.
15--
16-- One major advantage of strict data structures as accumulators in folds and
17-- scans is that it helps the compiler optimize the code much better by
18-- unboxing. In a big tight loop the difference could be huge.
19--
20module Streamly.Internal.Data.Maybe.Strict
21 ( Maybe' (..)
22 , toMaybe
23 )
24where
26-- | A strict 'Maybe'
27data Maybe' a = Just' !a | Nothing' deriving Show
29-- | Convert strict Maybe' to lazy Maybe
30{-# INLINABLE toMaybe #-}
31toMaybe :: Maybe' a -> Maybe a
32toMaybe Nothing' = Nothing
33toMaybe (Just' a) = Just a