136cd21 · rowtype-yoga/purescript-native

git.iko.soy/rowtype-yoga/purescript-native

Merge pull request #61 from chrissmoak/guards-scope

Allow guards access to current scope

commit136cd2131d3f121d77d2eb23e6d0a908f8dc33ed authorPhil Freeman <paf31@cantab.net> dateThu 7 Nov 2013, 06:46 (13 years ago) parent2f06996 10746bf

3 files changed+20−5

compare with golang

unifiedsplit

examples/failing/PatternScope.ps+7 examples/passing/Guards.ps+5 src/Language/PureScript/TypeChecker/Types.hs+8−5

examples/failing/PatternScope.psnew file+7

@@ -0,0 +1,7 @@

1+-- Pattern scope doesn't leak

2+foobar = \x -> do

3+ var y = case x of

4+ z | z % 2 == 0 -> 1

5+ _ -> 2

6+ return z

examples/passing/Guards.ps+5

@@ -1,3 +1,8 @@

11collatz = \x -> case x of

22 y | y % 2 == 0 -> y / 2

33 y -> y * 3 + 1

5+-- Guards have access to current scope

6+collatz2 = \x, y -> case x of

7+ z | y > 0 -> z / 2

8+ z -> z * 3 + 1

src/Language/PureScript/TypeChecker/Types.hs+8−5

@@ -436,10 +436,13 @@ typeConstraintsForBinder val b@(NamedBinder name binder) = do

436436 me <- fresh

437437 (cs, m) <- typeConstraintsForBinder val binder

438438 return (TypeConstraint me (TUnknown val) (BinderOrigin b) : cs, M.insert name me m)

439−typeConstraintsForBinder val b@(GuardedBinder cond binder) = do

440− (cs1, m) <- typeConstraintsForBinder val binder

441− (cs2, n) <- typeConstraints m cond

442− return (TypeConstraint n Boolean (ValueOrigin cond) : cs1 ++ cs2, m)

439+

440+typeConstraintsForGuardedBinder :: M.Map Ident Int -> Int -> Binder -> Check ([TypeConstraint], M.Map Ident Int)

441+typeConstraintsForGuardedBinder m val b@(GuardedBinder cond binder) = do

442+ (cs1, m1) <- typeConstraintsForBinder val binder

443+ (cs2, n) <- typeConstraints (m `M.union` m1) cond

444+ return (TypeConstraint n Boolean (ValueOrigin cond) : cs1 ++ cs2, m1)

445+typeConstraintsForGuardedBinder m val b = typeConstraintsForBinder val b >>= return

443446

444447constantBinder :: Binder -> Int -> Type -> Check ([TypeConstraint], M.Map Ident Int)

445448constantBinder b val ty = return ([TypeConstraint val ty (BinderOrigin b)], M.empty)

@@ -447,7 +450,7 @@ constantBinder b val ty = return ([TypeConstraint val ty (BinderOrigin b)], M.em

447450typeConstraintsForBinders :: M.Map Ident Int -> Int -> Int -> [(Binder, Value)] -> Check [TypeConstraint]

448451typeConstraintsForBinders _ _ _ [] = return []

449452typeConstraintsForBinders m nval ret ((binder, val):bs) = do

450− (cs1, m1) <- typeConstraintsForBinder nval binder

453+ (cs1, m1) <- typeConstraintsForGuardedBinder m nval binder

451454 (cs2, n2) <- typeConstraints (m `M.union` m1) val

452455 cs3 <- typeConstraintsForBinders m nval ret bs

453456 return (TypeConstraint n2 (TUnknown ret) (BinderOrigin binder) : cs1 ++ cs2 ++ cs3)