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Fix #810 and #814: don't infer polymorphic types for data constructors. #835

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Merged
paf31 merged 1 commit into from
Feb 3, 2015
Merged

Fix #810 and #814: don't infer polymorphic types for data constructors. #835

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11 changes: 11 additions & 0 deletions examples/passing/810.purs
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Original file line number Diff line number Diff line change
@@ -0,0 +1,11 @@
module Main where

data Maybe a = Nothing | Just a

test :: forall a. Maybe a -> Maybe a
test m = o.x
where
o = case m of Nothing -> { x : Nothing }
Just a -> { x : Just a }

main = Debug.Trace.trace "Done"
5 changes: 3 additions & 2 deletions src/Language/PureScript/TypeChecker/Types.hs
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Expand Up @@ -52,6 +52,7 @@ import Language.PureScript.Errors
import Language.PureScript.Kinds
import Language.PureScript.Names
import Language.PureScript.Pretty
import Language.PureScript.Traversals
import Language.PureScript.TypeChecker.Entailment
import Language.PureScript.TypeChecker.Kinds
import Language.PureScript.TypeChecker.Monad
Expand Down Expand Up @@ -271,8 +272,8 @@ infer' v@(Constructor c) = do
env <- getEnv
case M.lookup c (dataConstructors env) of
Nothing -> throwError . strMsg $ "Constructor " ++ show c ++ " is undefined"
Just (_, _, ty) -> do ty' <- introduceSkolemScope <=< replaceAllTypeSynonyms $ ty
return $ TypedValue True v ty'
Just (_, _, ty) -> do (v', ty') <- sndM (introduceSkolemScope <=< replaceAllTypeSynonyms) <=< instantiatePolyTypeWithUnknowns v $ ty
return $ TypedValue True v' ty'
infer' (Case vals binders) = do
ts <- mapM infer vals
ret <- fresh
Expand Down