Tissevert/Mainate
1
0
Fork 0
Code Issues Pull requests Releases Wiki Activity

Lift restrictions on base version and abandon Semigroup instance

Browse source
This commit is contained in:
Tissevert 2019-05-03 19:06:24 +02:00
parent c481ea4981
commit a34e1e8806
2 changed files with 3 additions and 5 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
Mainate.cabal
View file

@ -21,6 +21,6 @@ library
exposed-modules: Stream exposed-modules: Stream
-- other-modules: -- other-modules:
-- other-extensions: -- other-extensions:
build-depends: base >=4.12 && <4.13 build-depends: base >=4.9 && <4.13
hs-source-dirs: src hs-source-dirs: src
default-language: Haskell2010 default-language: Haskell2010

6
src/Stream.hs
View file

@ -6,12 +6,10 @@ import Data.List (intercalate)
data Stream a = Stream [(a, Stream a)] deriving Show data Stream a = Stream [(a, Stream a)] deriving Show
instance Semigroup (Stream a) where
(<>) (Stream []) b = b
(<>) (Stream pairs) b = Stream $ (\(a, stream) -> (a, stream <> b)) <$> pairs
instance Monoid (Stream a) where instance Monoid (Stream a) where
mempty = fromList [] mempty = fromList []
mappend (Stream []) b = b
mappend (Stream pairs) b = Stream $ (\(a, stream) -> (a, stream `mappend` b)) <$> pairs
fromList :: [a] -> Stream a fromList :: [a] -> Stream a
fromList [] = Stream [] fromList [] = Stream []