25cb5da · streamly · git.iko.soy

git.iko.soy/streamly

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Use rewrite rules to simplify sepcialized code

25cb5daHarendra Kumar8 years ago

src/Streamly/Streams/StreamK/Type.hs+42−3

compare with master

unifiedsplit

@@ -10,6 +10,8 @@

10{-# LANGUAGE RankNTypes #-}

11{-# LANGUAGE UndecidableInstances #-} -- XXX

13+#include "../inline.hs"

14+

13-- |

15-- |

14-- Module : Streamly.Streams.StreamK.Type

16-- Module : Streamly.Streams.StreamK.Type

@@ -182,10 +184,13 @@ adapt = fromStream . toStream

182-- Currently we always use "SVar Stream" and therefore a different State type

184-- Currently we always use "SVar Stream" and therefore a different State type

183-- parameterized by that stream.

185-- parameterized by that stream.

184--

186--

187+-- XXX Since t is coercible we should be able to coerce k

188+-- mkStream k = fromStream $ MkStream $ coerce k

189+--

185-- | Build a stream from an 'SVar', a stop continuation, a singleton stream

190-- | Build a stream from an 'SVar', a stop continuation, a singleton stream

186-- continuation and a yield continuation.

191-- continuation and a yield continuation.

187−{-# INLINE mkStream #-}

192+{-# INLINE_EARLY mkStream #-}

188−mkStream:: IsStream t

193+mkStream :: IsStream t

189 => (forall r. State Stream m a

194 => (forall r. State Stream m a

190 -> (a -> t m a -> m r)

195 -> (a -> t m a -> m r)

191 -> (a -> m r)

196 -> (a -> m r)

@@ -196,6 +201,26 @@ mkStream k = fromStream $ MkStream $ \st yld sng stp ->

196 let yieldk a r = yld a (toStream r)

201 let yieldk a r = yld a (toStream r)

197 in k st yieldk sng stp

202 in k st yieldk sng stp

198

203

204+{-# RULES "mkStream from stream" mkStream = mkStreamFromStream #-}

205+mkStreamFromStream :: IsStream t

206+ => (forall r. State Stream m a

207+ -> (a -> Stream m a -> m r)

208+ -> (a -> m r)

209+ -> m r

210+ -> m r)

211+ -> t m a

212+mkStreamFromStream k = fromStream $ MkStream k

213+

214+{-# RULES "mkStream stream" mkStream = mkStreamStream #-}

215+mkStreamStream

216+ :: (forall r. State Stream m a

217+ -> (a -> Stream m a -> m r)

218+ -> (a -> m r)

219+ -> m r

220+ -> m r)

221+ -> Stream m a

222+mkStreamStream = MkStream

223+

199-- | A terminal function that has no continuation to follow.

224-- | A terminal function that has no continuation to follow.

200type StopK m = forall r. m r -> m r

225type StopK m = forall r. m r -> m r

201

226

@@ -229,7 +254,7 @@ consK k r = mkStream $ \_ yld _ _ -> k (\x -> yld x r)

229-- | Fold a stream by providing an SVar, a stop continuation, a singleton

254-- | Fold a stream by providing an SVar, a stop continuation, a singleton

230-- continuation and a yield continuation. The stream would share the current

255-- continuation and a yield continuation. The stream would share the current

231-- SVar passed via the State.

256-- SVar passed via the State.

232−{-# INLINE foldStreamShared #-}

257+{-# INLINE_EARLY foldStreamShared #-}

233foldStreamShared

258foldStreamShared

234 :: IsStream t

259 :: IsStream t

235 => State Stream m a

260 => State Stream m a

@@ -243,6 +268,20 @@ foldStreamShared st yld sng stp m =

243 MkStream k = toStream m

268 MkStream k = toStream m

244 in k st yieldk sng stp

269 in k st yieldk sng stp

245

270

271+-- XXX write a similar rule for foldStream as well?

272+{-# RULES "foldStreamShared from stream"

273+ foldStreamShared = foldStreamSharedStream #-}

274+foldStreamSharedStream

275+ :: State Stream m a

276+ -> (a -> Stream m a -> m r)

277+ -> (a -> m r)

278+ -> m r

279+ -> Stream m a

280+ -> m r

281+foldStreamSharedStream st yld sng stp m =

282+ let MkStream k = toStream m

283+ in k st yld sng stp

284+

246-- | Fold a stream by providing a State, stop continuation, a singleton

285-- | Fold a stream by providing a State, stop continuation, a singleton

247-- continuation and a yield continuation. The stream will not use the SVar

286-- continuation and a yield continuation. The stream will not use the SVar

248-- passed via State.

287-- passed via State.