3ba23c7 · rowtype-yoga/purescript-native

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

Warn on unused type variable

commit3ba23c75226e06b5ed62e967ab03df73621eb79c authorGary Burgess <gary.burgess@gmail.com> dateSun 13 Sep 2015, 13:32 (11 years ago) parent0888ada

2 files changed+21−7

compare with golang

unifiedsplit

src/Language/PureScript/Errors.hs+4 src/Language/PureScript/Linter.hs+17−7

src/Language/PureScript/Errors.hs+4

@@ -141,6 +141,7 @@ data SimpleErrorMessage

141141 | TransitiveExportError DeclarationRef [DeclarationRef]

142142 | ShadowedName Ident

143143 | ShadowedTypeVar String

144+ | UnusedTypeVar String

144145 | WildcardInferredType Type

145146 | NotExhaustivePattern [[Binder]] Bool

146147 | OverlappingPattern [[Binder]] Bool

@@ -268,6 +269,7 @@ errorCode em = case unwrapErrorMessage em of

268269 TransitiveExportError{} -> "TransitiveExportError"

269270 ShadowedName{} -> "ShadowedName"

270271 ShadowedTypeVar{} -> "ShadowedTypeVar"

272+ UnusedTypeVar{} -> "UnusedTypeVar"

271273 WildcardInferredType{} -> "WildcardInferredType"

272274 NotExhaustivePattern{} -> "NotExhaustivePattern"

273275 OverlappingPattern{} -> "OverlappingPattern"

@@ -633,6 +635,8 @@ prettyPrintSingleError full level e = prettyPrintErrorMessage <$> onTypesInError

633635 line $ "Name '" ++ showIdent nm ++ "' was shadowed"

634636 goSimple (ShadowedTypeVar tv) =

635637 line $ "Type variable '" ++ tv ++ "' was shadowed"

638+ goSimple (UnusedTypeVar tv) =

639+ line $ "Type variable '" ++ tv ++ "' was declared but not used"

636640 goSimple (ClassOperator className opName) =

637641 paras [ line $ "Class '" ++ runProperName className ++ "' declares operator " ++ showIdent opName ++ "."

638642 , indent $ line "This may be disallowed in the future - consider declaring a named member in the class and making the operator an alias:"

src/Language/PureScript/Linter.hs+17−7

@@ -19,7 +19,7 @@

1919

2020module Language.PureScript.Linter (lint, module L) where

2121

22−import Data.List (mapAccumL, nub)

22+import Data.List (mapAccumL, nub, (\\))

2323import Data.Maybe (mapMaybe)

2424import Data.Monoid

2525

@@ -60,7 +60,7 @@ lint (Module _ _ mn ds _) = censor (onErrorMessages (ErrorInModule mn)) $ mapM_

6060

6161 f' :: Declaration -> MultipleErrors

6262 f' (PositionedDeclaration pos _ dec) = onErrorMessages (PositionedError pos) (f' dec)

63− f' dec = f dec <> checkShadowedTypeVars dec

63+ f' dec = f dec <> checkTypeVars dec

6464

6565 in tell (f' d)

6666 where

@@ -90,17 +90,27 @@ lint (Module _ _ mn ds _) = censor (onErrorMessages (ErrorInModule mn)) $ mapM_

9090 bindName :: S.Set Ident -> Ident -> (S.Set Ident, MultipleErrors)

9191 bindName = bind ShadowedName

9292

93− checkShadowedTypeVars :: Declaration -> MultipleErrors

94− checkShadowedTypeVars d =

95− let (f, _, _, _, _) = accumTypes go in f d

93+ checkTypeVars :: Declaration -> MultipleErrors

94+ checkTypeVars d =

95+ let (checkShadow, _, _, _, _) = accumTypes (everythingWithContextOnTypes S.empty mempty mappend step)

96+ (checkUnused, _, _, _, _) = accumTypes findUnused

97+ in checkShadow d <> checkUnused d

9698 where

97− go :: Type -> MultipleErrors

98− go = everythingWithContextOnTypes S.empty mempty mappend step

9999 step :: S.Set String -> Type -> (S.Set String, MultipleErrors)

100100 step s (ForAll tv _ _) = bindVar s tv

101101 step s _ = (s, mempty)

102102 bindVar :: S.Set String -> String -> (S.Set String, MultipleErrors)

103103 bindVar = bind ShadowedTypeVar

104+ findUnused :: Type -> MultipleErrors

105+ findUnused ty =

106+ let used = usedTypeVariables ty

107+ declared = everythingOnTypes (++) go ty

108+ unused = nub declared \\ nub used

109+ in foldl (<>) mempty $ map (errorMessage . UnusedTypeVar) unused

110+ where

111+ go :: Type -> [String]

112+ go (ForAll tv _ _) = [tv]

113+ go _ = []

104114

105115 bind :: (Ord a) => (a -> SimpleErrorMessage) -> S.Set a -> a -> (S.Set a, MultipleErrors)

106116 bind mkError s name | name `S.member` s = (s, errorMessage (mkError name))