b8bb12b · rowtype-yoga/purescript-native

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

Fix #2379, add error message for unknown classes (#2396)

* Fix #2379, add error message for unknown classes * Typo, fix cabal file

commitb8bb12b5fec663509040413ca39816bab02ddc4c authorPhil Freeman <paf31@cantab.net> dateSat 22 Oct 2016, 12:36 (10 years ago) parenta8756f0

6 files changed+27−2

compare with golang

unifiedsplit

examples/failing/2379.purs+6 examples/failing/2379/Lib.purs+9 purescript.cabal+1 src/Language/PureScript/AST/Declarations.hs+1 src/Language/PureScript/Errors.hs+6 src/Language/PureScript/TypeChecker/Entailment.hs+4−2

examples/failing/2379.pursnew file+6

@@ -0,0 +1,6 @@

1+-- @shouldFailWith UnknownClass

2+module Main where

4+import Lib

6+test = x [1, 2, 3]

examples/failing/2379/Lib.pursnew file+9

@@ -0,0 +1,9 @@

1+module Lib (class X, x) where

3+class X a where

4+ x :: a -> String

6+class Y a

8+instance xArray :: Y a => X (Array a) where

9+ x _ = "[]"

purescript.cabal+1

@@ -56,6 +56,7 @@ extra-source-files: examples/passing/*.purs

5656 , examples/failing/*.purs

5757 , examples/failing/1733/*.purs

5858 , examples/failing/2378/*.purs

59+ , examples/failing/2379/*.purs

5960 , examples/failing/ConflictingExports/*.purs

6061 , examples/failing/ConflictingImports/*.purs

6162 , examples/failing/ConflictingImports2/*.purs

src/Language/PureScript/AST/Declarations.hs+1

@@ -83,6 +83,7 @@ data SimpleErrorMessage

8383 | ConstrainedTypeUnified Type Type

8484 | OverlappingInstances (Qualified (ProperName 'ClassName)) [Type] [Qualified Ident]

8585 | NoInstanceFound Constraint

86+ | UnknownClass (Qualified (ProperName 'ClassName))

8687 | PossiblyInfiniteInstance (Qualified (ProperName 'ClassName)) [Type]

8788 | CannotDerive (Qualified (ProperName 'ClassName)) [Type]

8889 | InvalidNewtypeInstance (Qualified (ProperName 'ClassName)) [Type]

src/Language/PureScript/Errors.hs+6

@@ -118,6 +118,7 @@ errorCode em = case unwrapErrorMessage em of

118118 ConstrainedTypeUnified{} -> "ConstrainedTypeUnified"

119119 OverlappingInstances{} -> "OverlappingInstances"

120120 NoInstanceFound{} -> "NoInstanceFound"

121+ UnknownClass{} -> "UnknownClass"

121122 PossiblyInfiniteInstance{} -> "PossiblyInfiniteInstance"

122123 CannotDerive{} -> "CannotDerive"

123124 InvalidNewtypeInstance{} -> "InvalidNewtypeInstance"

@@ -599,6 +600,11 @@ prettyPrintSingleError (PPEOptions codeColor full level showWiki) e = flip evalS

599600 , line "They may be disallowed completely in a future version of the compiler."

600601 ]

601602 renderSimpleErrorMessage OverlappingInstances{} = internalError "OverlappingInstances: empty instance list"

603+ renderSimpleErrorMessage (UnknownClass nm) =

604+ paras [ line "No type class instance was found for class"

605+ , markCodeBox $ indent $ line (showQualified runProperName nm)

606+ , line "because the class was not in scope. Perhaps it was not exported."

607+ ]

602608 renderSimpleErrorMessage (NoInstanceFound (Constraint C.Fail [ ty ] _)) | Just box <- toTypelevelString ty =

603609 paras [ line "A custom type error occurred while solving type class constraints:"

604610 , indent box

src/Language/PureScript/TypeChecker/Entailment.hs+4−2

@@ -150,8 +150,10 @@ entails SolverOptions{..} constraint context hints =

150150 inferred <- lift get

151151 -- We need information about functional dependencies, so we have to look up the class

152152 -- name in the environment:

153− let findClass = fromMaybe (internalError "entails: type class not found in environment") . M.lookup className'

154− TypeClassData{ typeClassDependencies } <- lift . lift $ gets (findClass . typeClasses . checkEnv)

153+ classesInScope <- lift . lift $ gets (typeClasses . checkEnv)

154+ TypeClassData{ typeClassDependencies } <- case M.lookup className' classesInScope of

155+ Nothing -> throwError . errorMessage $ UnknownClass className'

156+ Just tcd -> pure tcd

155157 let instances =

156158 [ (substs, tcd)

157159 | tcd <- forClassName (combineContexts context inferred) className' tys''