00a4705 · rowtype-yoga/purescript-native

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

on golang help sign in

Friendlier errors

00a4705Phil Freeman11 years ago

src/Language/PureScript/Errors.hs+102−106

compare with golang

unifiedsplit

@@ -42,7 +42,6 @@ import Control.Monad.Trans.State.Lazy

42import Control.Arrow(first)

44import Language.PureScript.AST

45−import Language.PureScript.Environment (isObject, isFunction)

46import Language.PureScript.Pretty

45import Language.PureScript.Pretty

47import Language.PureScript.Types

46import Language.PureScript.Types

48import Language.PureScript.Names

47import Language.PureScript.Names

@@ -62,13 +61,11 @@ data SimpleErrorMessage

62 | MissingFFIModule ModuleName

61 | MissingFFIModule ModuleName

63 | MultipleFFIModules ModuleName [FilePath]

62 | MultipleFFIModules ModuleName [FilePath]

64 | UnnecessaryFFIModule ModuleName FilePath

63 | UnnecessaryFFIModule ModuleName FilePath

65− | InvalidExternsFile FilePath

66 | CannotGetFileInfo FilePath

64 | CannotGetFileInfo FilePath

67 | CannotReadFile FilePath

65 | CannotReadFile FilePath

68 | CannotWriteFile FilePath

66 | CannotWriteFile FilePath

69 | InfiniteType Type

67 | InfiniteType Type

70 | InfiniteKind Kind

68 | InfiniteKind Kind

71− | CannotReorderOperators

72 | MultipleFixities Ident

69 | MultipleFixities Ident

73 | OrphanTypeDeclaration Ident

70 | OrphanTypeDeclaration Ident

74 | OrphanFixityDeclaration String

71 | OrphanFixityDeclaration String

@@ -112,7 +109,6 @@ data SimpleErrorMessage

112 | UndefinedTypeVariable ProperName

109 | UndefinedTypeVariable ProperName

113 | PartiallyAppliedSynonym (Qualified ProperName)

110 | PartiallyAppliedSynonym (Qualified ProperName)

114 | EscapedSkolem (Maybe Expr)

111 | EscapedSkolem (Maybe Expr)

115− | UnspecifiedSkolemScope

116 | TypesDoNotUnify Type Type

112 | TypesDoNotUnify Type Type

117 | KindsDoNotUnify Kind Kind

113 | KindsDoNotUnify Kind Kind

118 | ConstrainedTypeUnified Type Type

114 | ConstrainedTypeUnified Type Type

@@ -126,10 +122,9 @@ data SimpleErrorMessage

126 | ArgListLengthsDiffer Ident

122 | ArgListLengthsDiffer Ident

127 | OverlappingArgNames (Maybe Ident)

123 | OverlappingArgNames (Maybe Ident)

128 | MissingClassMember Ident

124 | MissingClassMember Ident

129− | ExtraneousClassMember Ident

125+ | ExtraneousClassMember Ident (Qualified ProperName)

130 | ExpectedType Type Kind

126 | ExpectedType Type Kind

131 | IncorrectConstructorArity (Qualified ProperName)

127 | IncorrectConstructorArity (Qualified ProperName)

132− | SubsumptionCheckFailed

133 | ExprDoesNotHaveType Expr Type

128 | ExprDoesNotHaveType Expr Type

134 | PropertyIsMissing String Type

129 | PropertyIsMissing String Type

135 | CannotApplyFunction Type Expr

130 | CannotApplyFunction Type Expr

@@ -202,13 +197,11 @@ errorCode em = case unwrapErrorMessage em of

202 MissingFFIModule{} -> "MissingFFIModule"

197 MissingFFIModule{} -> "MissingFFIModule"

203 MultipleFFIModules{} -> "MultipleFFIModules"

198 MultipleFFIModules{} -> "MultipleFFIModules"

204 UnnecessaryFFIModule{} -> "UnnecessaryFFIModule"

199 UnnecessaryFFIModule{} -> "UnnecessaryFFIModule"

205− InvalidExternsFile{} -> "InvalidExternsFile"

206 CannotGetFileInfo{} -> "CannotGetFileInfo"

200 CannotGetFileInfo{} -> "CannotGetFileInfo"

207 CannotReadFile{} -> "CannotReadFile"

201 CannotReadFile{} -> "CannotReadFile"

208 CannotWriteFile{} -> "CannotWriteFile"

202 CannotWriteFile{} -> "CannotWriteFile"

209 InfiniteType{} -> "InfiniteType"

203 InfiniteType{} -> "InfiniteType"

210 InfiniteKind{} -> "InfiniteKind"

204 InfiniteKind{} -> "InfiniteKind"

211− CannotReorderOperators -> "CannotReorderOperators"

212 MultipleFixities{} -> "MultipleFixities"

205 MultipleFixities{} -> "MultipleFixities"

213 OrphanTypeDeclaration{} -> "OrphanTypeDeclaration"

206 OrphanTypeDeclaration{} -> "OrphanTypeDeclaration"

214 OrphanFixityDeclaration{} -> "OrphanFixityDeclaration"

207 OrphanFixityDeclaration{} -> "OrphanFixityDeclaration"

@@ -252,7 +245,6 @@ errorCode em = case unwrapErrorMessage em of

252 UndefinedTypeVariable{} -> "UndefinedTypeVariable"

245 UndefinedTypeVariable{} -> "UndefinedTypeVariable"

253 PartiallyAppliedSynonym{} -> "PartiallyAppliedSynonym"

246 PartiallyAppliedSynonym{} -> "PartiallyAppliedSynonym"

254 EscapedSkolem{} -> "EscapedSkolem"

247 EscapedSkolem{} -> "EscapedSkolem"

255− UnspecifiedSkolemScope -> "UnspecifiedSkolemScope"

256 TypesDoNotUnify{} -> "TypesDoNotUnify"

248 TypesDoNotUnify{} -> "TypesDoNotUnify"

257 KindsDoNotUnify{} -> "KindsDoNotUnify"

249 KindsDoNotUnify{} -> "KindsDoNotUnify"

258 ConstrainedTypeUnified{} -> "ConstrainedTypeUnified"

250 ConstrainedTypeUnified{} -> "ConstrainedTypeUnified"

@@ -269,7 +261,6 @@ errorCode em = case unwrapErrorMessage em of

269 ExtraneousClassMember{} -> "ExtraneousClassMember"

261 ExtraneousClassMember{} -> "ExtraneousClassMember"

270 ExpectedType{} -> "ExpectedType"

262 ExpectedType{} -> "ExpectedType"

271 IncorrectConstructorArity{} -> "IncorrectConstructorArity"

263 IncorrectConstructorArity{} -> "IncorrectConstructorArity"

272− SubsumptionCheckFailed -> "SubsumptionCheckFailed"

273 ExprDoesNotHaveType{} -> "ExprDoesNotHaveType"

264 ExprDoesNotHaveType{} -> "ExprDoesNotHaveType"

274 PropertyIsMissing{} -> "PropertyIsMissing"

265 PropertyIsMissing{} -> "PropertyIsMissing"

275 CannotApplyFunction{} -> "CannotApplyFunction"

266 CannotApplyFunction{} -> "CannotApplyFunction"

@@ -385,9 +376,9 @@ prettyPrintSingleError full level e = prettyPrintErrorMessage . positionHintsFir

385 prettyPrintErrorMessage (ErrorMessage hints simple) =

376 prettyPrintErrorMessage (ErrorMessage hints simple) =

386 paras $

377 paras $

387 map renderHint hints ++

378 map renderHint hints ++

388− renderSimpleErrorMessage simple :

379+ [ renderSimpleErrorMessage simple

389− suggestions simple ++

390− [line $ "See " ++ wikiUri ++ " for more information, or to contribute content related to this " ++ levelText ++ "."]

380+ , line $ "See " ++ wikiUri ++ " for more information, or to contribute content related to this " ++ levelText ++ "."

381+ ]

391 where

382 where

392 wikiUri :: String

383 wikiUri :: String

393 wikiUri = "https://github.com/purescript/purescript/wiki/Error-Code-" ++ errorCode e

384 wikiUri = "https://github.com/purescript/purescript/wiki/Error-Code-" ++ errorCode e

@@ -410,37 +401,37 @@ prettyPrintSingleError full level e = prettyPrintErrorMessage . positionHintsFir

410 , prettyPrintParseError err

401 , prettyPrintParseError err

411 ]

402 ]

412 renderSimpleErrorMessage (ErrorParsingFFIModule path) =

403 renderSimpleErrorMessage (ErrorParsingFFIModule path) =

413− paras [ line "Unable to parse module from FFI file: "

404+ paras [ line "Unable to parse foreign module:"

414 , indent . line $ path

405 , indent . line $ path

406+ , line "Ensure that all foreign modules contain a single module header at the start of a line, as follows:"

407+ , indent $ line "// module A.B.C"

415 ]

408 ]

416 renderSimpleErrorMessage (ErrorParsingModule err) =

409 renderSimpleErrorMessage (ErrorParsingModule err) =

417 paras [ line "Unable to parse module: "

410 paras [ line "Unable to parse module: "

418 , prettyPrintParseError err

411 , prettyPrintParseError err

419 ]

412 ]

420 renderSimpleErrorMessage (MissingFFIModule mn) =

413 renderSimpleErrorMessage (MissingFFIModule mn) =

421− line $ "Missing FFI implementations for module " ++ runModuleName mn

414+ paras [ line $ "Missing foreign module implementation for module " ++ runModuleName mn

415+ , line $ "Provide your foreign module implementation using the --ffi command line option, and ensure that your module contains the following module header:"

416+ , indent . line $ "// module " ++ runModuleName mn

417+ ]

422 renderSimpleErrorMessage (UnnecessaryFFIModule mn path) =

418 renderSimpleErrorMessage (UnnecessaryFFIModule mn path) =

423− paras [ line $ "Unnecessary FFI implementations have been provided for module " ++ runModuleName mn ++ ": "

419+ paras [ line $ "An unnecessary foreign module implementation was provided for module " ++ runModuleName mn ++ ": "

424 , indent . line $ path

420 , indent . line $ path

421+ , line $ "Module " ++ runModuleName mn ++ " does not contain any foreign import declarations, so a foreign module is not necessary."

425 ]

422 ]

426 renderSimpleErrorMessage (MultipleFFIModules mn paths) =

423 renderSimpleErrorMessage (MultipleFFIModules mn paths) =

427− paras [ line $ "Multiple FFI implementations have been provided for module " ++ runModuleName mn ++ ": "

424+ paras [ line $ "Multiple foreign module implementations have been provided for module " ++ runModuleName mn ++ ": "

428 , indent . paras $ map line paths

425 , indent . paras $ map line paths

429− ]

426+ , line "Foreign modules are identified by a unique module name, as follows:"

430− renderSimpleErrorMessage (InvalidExternsFile path) =

427+ , indent $ line "// module A.B.C"

431− paras [ line "Externs file is invalid: "

432− , indent . line $ path

433 ]

428 ]

434 renderSimpleErrorMessage InvalidDoBind =

429 renderSimpleErrorMessage InvalidDoBind =

435− line "Bind statement cannot be the last statement in a do block. The last statement must be an expression."

430+ line "The last statement in a 'do' block must be an expression, but this block ends with a binder."

436 renderSimpleErrorMessage InvalidDoLet =

431 renderSimpleErrorMessage InvalidDoLet =

437− line "Let statement cannot be the last statement in a do block. The last statement must be an expression."

432+ line "The last statement in a 'do' block must be an expression, but this block ends with a let binding."

438− renderSimpleErrorMessage CannotReorderOperators =

439− line "Unable to reorder operators"

440− renderSimpleErrorMessage UnspecifiedSkolemScope =

441− line "Skolem variable scope is unspecified"

442 renderSimpleErrorMessage OverlappingNamesInLet =

433 renderSimpleErrorMessage OverlappingNamesInLet =

443− line "Overlapping names in let binding."

434+ line "The same name was used more than once in a let binding."

444 renderSimpleErrorMessage (InfiniteType ty) =

435 renderSimpleErrorMessage (InfiniteType ty) =

445 paras [ line "An infinite type was inferred for an expression: "

436 paras [ line "An infinite type was inferred for an expression: "

446 , indent $ typeAsBox ty

437 , indent $ typeAsBox ty

@@ -450,17 +441,17 @@ prettyPrintSingleError full level e = prettyPrintErrorMessage . positionHintsFir

450 , indent $ line $ prettyPrintKind ki

441 , indent $ line $ prettyPrintKind ki

451 ]

442 ]

452 renderSimpleErrorMessage (MultipleFixities name) =

443 renderSimpleErrorMessage (MultipleFixities name) =

453− line $ "Multiple fixity declarations for " ++ showIdent name

444+ line $ "There are multiple fixity/precedence declarations for " ++ showIdent name

454 renderSimpleErrorMessage (OrphanTypeDeclaration nm) =

445 renderSimpleErrorMessage (OrphanTypeDeclaration nm) =

455− line $ "Orphan type declaration for " ++ showIdent nm

446+ line $ "The type declaration for " ++ showIdent nm ++ " should be followed by its definition."

456 renderSimpleErrorMessage (OrphanFixityDeclaration op) =

447 renderSimpleErrorMessage (OrphanFixityDeclaration op) =

457− line $ "Orphan fixity declaration for " ++ show op

448+ line $ "The fixity/precedence declaration for " ++ show op ++ " should appear in the same module as its definition."

458 renderSimpleErrorMessage (RedefinedModule name filenames) =

449 renderSimpleErrorMessage (RedefinedModule name filenames) =

459− paras [ line ("Module " ++ runModuleName name ++ " has been defined multiple times:")

450+ paras [ line ("The module " ++ runModuleName name ++ " has been defined multiple times:")

460 , indent . paras $ map (line . displaySourceSpan) filenames

451 , indent . paras $ map (line . displaySourceSpan) filenames

461 ]

452 ]

462 renderSimpleErrorMessage (RedefinedIdent name) =

453 renderSimpleErrorMessage (RedefinedIdent name) =

463− line $ "Name " ++ showIdent name ++ " has been defined multiple times"

454+ line $ "The name " ++ showIdent name ++ " has been defined multiple times"

464 renderSimpleErrorMessage (UnknownModule mn) =

455 renderSimpleErrorMessage (UnknownModule mn) =

465 line $ "Unknown module " ++ runModuleName mn

456 line $ "Unknown module " ++ runModuleName mn

466 renderSimpleErrorMessage (UnknownType name) =

457 renderSimpleErrorMessage (UnknownType name) =

@@ -474,25 +465,30 @@ prettyPrintSingleError full level e = prettyPrintErrorMessage . positionHintsFir

474 renderSimpleErrorMessage (UnknownDataConstructor dc tc) =

465 renderSimpleErrorMessage (UnknownDataConstructor dc tc) =

475 line $ "Unknown data constructor " ++ showQualified runProperName dc ++ foldMap ((" for type constructor " ++) . showQualified runProperName) tc

466 line $ "Unknown data constructor " ++ showQualified runProperName dc ++ foldMap ((" for type constructor " ++) . showQualified runProperName) tc

476 renderSimpleErrorMessage (UnknownImportType mn name) =

467 renderSimpleErrorMessage (UnknownImportType mn name) =

477− line $ "Module " ++ runModuleName mn ++ " does not export type " ++ runProperName name

468+ line $ "The type " ++ runProperName name ++ " is not exported by the module " ++ runModuleName mn

478 renderSimpleErrorMessage (UnknownExportType name) =

469 renderSimpleErrorMessage (UnknownExportType name) =

479 line $ "Cannot export unknown type " ++ runProperName name

470 line $ "Cannot export unknown type " ++ runProperName name

480 renderSimpleErrorMessage (UnknownImportTypeClass mn name) =

471 renderSimpleErrorMessage (UnknownImportTypeClass mn name) =

481− line $ "Module " ++ runModuleName mn ++ " does not export type class " ++ runProperName name

472+ line $ "The type class " ++ runProperName name ++ " is not exported by the module " ++ runModuleName mn

482 renderSimpleErrorMessage (UnknownExportTypeClass name) =

473 renderSimpleErrorMessage (UnknownExportTypeClass name) =

483 line $ "Cannot export unknown type class " ++ runProperName name

474 line $ "Cannot export unknown type class " ++ runProperName name

484 renderSimpleErrorMessage (UnknownImportValue mn name) =

475 renderSimpleErrorMessage (UnknownImportValue mn name) =

485− line $ "Module " ++ runModuleName mn ++ " does not export value " ++ showIdent name

476+ line $ "The value " ++ showIdent name ++ " is not exported by the module " ++ runModuleName mn

486 renderSimpleErrorMessage (UnknownExportValue name) =

477 renderSimpleErrorMessage (UnknownExportValue name) =

487 line $ "Cannot export unknown value " ++ showIdent name

478 line $ "Cannot export unknown value " ++ showIdent name

488 renderSimpleErrorMessage (UnknownExportModule name) =

479 renderSimpleErrorMessage (UnknownExportModule name) =

480+ paras [ line $ "Cannot export unknown module " ++ runModuleName name

489− line $ "Cannot export unknown module " ++ runModuleName name ++ ", it either does not exist or has not been imported by the current module"

481+ , line "It either does not exist or has not been imported by the current module."

482+ ]

490 renderSimpleErrorMessage (UnknownImportDataConstructor mn tcon dcon) =

483 renderSimpleErrorMessage (UnknownImportDataConstructor mn tcon dcon) =

491− line $ "Module " ++ runModuleName mn ++ " does not export data constructor " ++ runProperName dcon ++ " for type " ++ runProperName tcon

484+ line $ "The data constructor " ++ runProperName dcon ++ " (for type " ++ runProperName tcon ++ ") is not exported by the module " ++ runModuleName mn

492 renderSimpleErrorMessage (UnknownExportDataConstructor tcon dcon) =

485 renderSimpleErrorMessage (UnknownExportDataConstructor tcon dcon) =

493− line $ "Cannot export data constructor " ++ runProperName dcon ++ " for type " ++ runProperName tcon ++ " as it has not been declared"

486+ line $ "Cannot export data constructor " ++ runProperName dcon ++ " for type " ++ runProperName tcon ++ ", as it has not been declared."

494 renderSimpleErrorMessage (ConflictingImport nm mn) =

487 renderSimpleErrorMessage (ConflictingImport nm mn) =

495− line $ "Cannot declare " ++ show nm ++ " since another declaration of that name was imported from " ++ runModuleName mn

488+ paras [ line $ "Cannot declare " ++ show nm ++ ", since another declaration of that name was imported from the module " ++ runModuleName mn

489+ , line $ "Consider hiding " ++ show nm ++ " when importing " ++ runModuleName mn ++ ":"

490+ , indent . line $ "import " ++ runModuleName mn ++ " hiding (" ++ nm ++ ")"

491+ ]

496 renderSimpleErrorMessage (ConflictingImports nm m1 m2) =

492 renderSimpleErrorMessage (ConflictingImports nm m1 m2) =

497 line $ "Conflicting imports for " ++ nm ++ " from modules " ++ runModuleName m1 ++ " and " ++ runModuleName m2

493 line $ "Conflicting imports for " ++ nm ++ " from modules " ++ runModuleName m1 ++ " and " ++ runModuleName m2

498 renderSimpleErrorMessage (ConflictingTypeDecls nm) =

494 renderSimpleErrorMessage (ConflictingTypeDecls nm) =

@@ -500,33 +496,41 @@ prettyPrintSingleError full level e = prettyPrintErrorMessage . positionHintsFir

500 renderSimpleErrorMessage (ConflictingCtorDecls nm) =

496 renderSimpleErrorMessage (ConflictingCtorDecls nm) =

501 line $ "Conflicting data constructor declarations for " ++ runProperName nm

497 line $ "Conflicting data constructor declarations for " ++ runProperName nm

502 renderSimpleErrorMessage (TypeConflictsWithClass nm) =

498 renderSimpleErrorMessage (TypeConflictsWithClass nm) =

503− line $ "Type " ++ runProperName nm ++ " conflicts with type class declaration of the same name"

499+ line $ "The type " ++ runProperName nm ++ " conflicts with type class declaration of the same name."

504 renderSimpleErrorMessage (CtorConflictsWithClass nm) =

500 renderSimpleErrorMessage (CtorConflictsWithClass nm) =

505− line $ "Data constructor " ++ runProperName nm ++ " conflicts with type class declaration of the same name"

501+ line $ "The data constructor " ++ runProperName nm ++ " conflicts with type class declaration of the same name."

506 renderSimpleErrorMessage (ClassConflictsWithType nm) =

502 renderSimpleErrorMessage (ClassConflictsWithType nm) =

507− line $ "Type class " ++ runProperName nm ++ " conflicts with type declaration of the same name"

503+ line $ "The type class " ++ runProperName nm ++ " conflicts with type declaration of the same name."

508 renderSimpleErrorMessage (ClassConflictsWithCtor nm) =

504 renderSimpleErrorMessage (ClassConflictsWithCtor nm) =

509− line $ "Type class " ++ runProperName nm ++ " conflicts with data constructor declaration of the same name"

505+ line $ "The type class " ++ runProperName nm ++ " conflicts with data constructor declaration of the same name."

510 renderSimpleErrorMessage (DuplicateModuleName mn) =

506 renderSimpleErrorMessage (DuplicateModuleName mn) =

511− line $ "Module " ++ runModuleName mn ++ " has been defined multiple times."

507+ line $ "The module " ++ runModuleName mn ++ " has been defined multiple times."

512 renderSimpleErrorMessage (DuplicateClassExport nm) =

508 renderSimpleErrorMessage (DuplicateClassExport nm) =

513 line $ "Duplicate export declaration for type class " ++ runProperName nm

509 line $ "Duplicate export declaration for type class " ++ runProperName nm

514 renderSimpleErrorMessage (DuplicateValueExport nm) =

510 renderSimpleErrorMessage (DuplicateValueExport nm) =

515 line $ "Duplicate export declaration for value " ++ showIdent nm

511 line $ "Duplicate export declaration for value " ++ showIdent nm

516 renderSimpleErrorMessage (CycleInDeclaration nm) =

512 renderSimpleErrorMessage (CycleInDeclaration nm) =

517− line $ "Cycle in declaration of " ++ showIdent nm

513+ paras [ line $ "The declaration of " ++ showIdent nm ++ " contains a cycle."

514+ , line $ "The value of " ++ showIdent nm ++ " may not be defined here, so this reference is not allowed."

515+ , line "You might be able to evaluate this expression lazily, using something like Control.Lazy.fix"

516+ ]

518 renderSimpleErrorMessage (CycleInModules mns) =

517 renderSimpleErrorMessage (CycleInModules mns) =

519− line $ "Cycle in module dependencies: " ++ intercalate ", " (map runModuleName mns)

518+ line $ "There is a cycle in the module dependencies: " ++ intercalate ", " (map runModuleName mns)

520− renderSimpleErrorMessage (CycleInTypeSynonym pn) =

519+ renderSimpleErrorMessage (CycleInTypeSynonym name) =

521− line $ "Cycle in type synonym" ++ foldMap ((" " ++) . runProperName) pn

520+ paras [ line $ case name of

521+ Just pn -> "A cycle appears in the definition of the type synonym " ++ runProperName pn

522+ Nothing -> "A cycle appears in a set of type synonym definitions."

523+ , line "Cycles are disallowed because they can lead to loops in the type checker."

524+ , line "Consider using a 'newtype' instead."

525+ ]

522 renderSimpleErrorMessage (NameIsUndefined ident) =

526 renderSimpleErrorMessage (NameIsUndefined ident) =

523− line $ showIdent ident ++ " is undefined"

527+ line $ "The name " ++ showIdent ident ++ " is undefined."

524 renderSimpleErrorMessage (NameNotInScope ident) =

528 renderSimpleErrorMessage (NameNotInScope ident) =

525− line $ showIdent ident ++ " may not be defined in the current scope"

529+ line $ "The name " ++ showIdent ident ++ " may not be defined in the current scope."

526 renderSimpleErrorMessage (UndefinedTypeVariable name) =

530 renderSimpleErrorMessage (UndefinedTypeVariable name) =

527− line $ "Type variable " ++ runProperName name ++ " is undefined"

531+ line $ "The type variable " ++ runProperName name ++ " is undefined."

528 renderSimpleErrorMessage (PartiallyAppliedSynonym name) =

532 renderSimpleErrorMessage (PartiallyAppliedSynonym name) =

529− paras [ line $ "Partially applied type synonym " ++ showQualified runProperName name

533+ paras [ line $ "The type synonym " ++ showQualified runProperName name ++ " is partially applied."

530 , line "Type synonyms must be applied to all of their type arguments."

534 , line "Type synonyms must be applied to all of their type arguments."

531 ]

535 ]

532 renderSimpleErrorMessage (EscapedSkolem binding) =

536 renderSimpleErrorMessage (EscapedSkolem binding) =

@@ -535,25 +539,25 @@ prettyPrintSingleError full level e = prettyPrintErrorMessage . positionHintsFir

535 , indent $ prettyPrintValue expr

539 , indent $ prettyPrintValue expr

536 ]) binding

540 ]) binding

537 renderSimpleErrorMessage (TypesDoNotUnify t1 t2)

541 renderSimpleErrorMessage (TypesDoNotUnify t1 t2)

538− = paras [ line "Cannot unify type"

542+ = paras [ line "The type"

539 , indent $ typeAsBox t1

543 , indent $ typeAsBox t1

540− , line "with type"

544+ , line "cannot be made equal to the type"

541 , indent $ typeAsBox t2

545 , indent $ typeAsBox t2

542 ]

546 ]

543 renderSimpleErrorMessage (KindsDoNotUnify k1 k2) =

547 renderSimpleErrorMessage (KindsDoNotUnify k1 k2) =

544− paras [ line "Cannot unify kind"

548+ paras [ line "The kind"

545 , indent $ line $ prettyPrintKind k1

549 , indent $ line $ prettyPrintKind k1

546− , line "with kind"

550+ , line "cannot be made equal to the kind"

547 , indent $ line $ prettyPrintKind k2

551 , indent $ line $ prettyPrintKind k2

548 ]

552 ]

549 renderSimpleErrorMessage (ConstrainedTypeUnified t1 t2) =

553 renderSimpleErrorMessage (ConstrainedTypeUnified t1 t2) =

550− paras [ line "Cannot unify constrained type"

554+ paras [ line "The constrained type"

551 , indent $ typeAsBox t1

555 , indent $ typeAsBox t1

552− , line "with type"

556+ , line "cannot be made equal to the kind"

553 , indent $ typeAsBox t2

557 , indent $ typeAsBox t2

554 ]

558 ]

555 renderSimpleErrorMessage (OverlappingInstances nm ts (d : ds)) =

559 renderSimpleErrorMessage (OverlappingInstances nm ts (d : ds)) =

556− paras [ line "Overlapping instances found for"

560+ paras [ line "Overlapping type class instances found for"

557 , indent $ Box.hsep 1 Box.left [ line (showQualified runProperName nm)

561 , indent $ Box.hsep 1 Box.left [ line (showQualified runProperName nm)

558 , Box.vcat Box.left (map typeAtomAsBox ts)

562 , Box.vcat Box.left (map typeAtomAsBox ts)

559 ]

563 ]

@@ -562,43 +566,43 @@ prettyPrintSingleError full level e = prettyPrintErrorMessage . positionHintsFir

562 ]

566 ]

563 renderSimpleErrorMessage OverlappingInstances{} = error "OverlappingInstances: empty instance list"

567 renderSimpleErrorMessage OverlappingInstances{} = error "OverlappingInstances: empty instance list"

564 renderSimpleErrorMessage (NoInstanceFound nm ts) =

568 renderSimpleErrorMessage (NoInstanceFound nm ts) =

565− paras [ line "No instance found for"

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

566 , indent $ Box.hsep 1 Box.left [ line (showQualified runProperName nm)

570 , indent $ Box.hsep 1 Box.left [ line (showQualified runProperName nm)

567 , Box.vcat Box.left (map typeAtomAsBox ts)

571 , Box.vcat Box.left (map typeAtomAsBox ts)

568 ]

572 ]

569 ]

573 ]

570 renderSimpleErrorMessage (PossiblyInfiniteInstance nm ts) =

574 renderSimpleErrorMessage (PossiblyInfiniteInstance nm ts) =

571− paras [ line "Instance for"

575+ paras [ line "The type class instance for"

572 , indent $ Box.hsep 1 Box.left [ line (showQualified runProperName nm)

576 , indent $ Box.hsep 1 Box.left [ line (showQualified runProperName nm)

573 , Box.vcat Box.left (map typeAtomAsBox ts)

577 , Box.vcat Box.left (map typeAtomAsBox ts)

574 ]

578 ]

575 , line "is possibly infinite."

579 , line "is possibly infinite."

576 ]

580 ]

577 renderSimpleErrorMessage (CannotDerive nm ts) =

581 renderSimpleErrorMessage (CannotDerive nm ts) =

578− paras [ line "Cannot derive an instance for"

582+ paras [ line "Cannot derive a type class instance for"

579 , indent $ Box.hsep 1 Box.left [ line (showQualified runProperName nm)

583 , indent $ Box.hsep 1 Box.left [ line (showQualified runProperName nm)

580 , Box.vcat Box.left (map typeAtomAsBox ts)

584 , Box.vcat Box.left (map typeAtomAsBox ts)

581 ]

585 ]

582 ]

586 ]

583 renderSimpleErrorMessage (CannotFindDerivingType nm) =

587 renderSimpleErrorMessage (CannotFindDerivingType nm) =

584− line $ "Cannot derive instance, because the type declaration for " ++ runProperName nm ++ " could not be found."

588+ line $ "Cannot derive a type class instance, because the type declaration for " ++ runProperName nm ++ " could not be found."

585 renderSimpleErrorMessage (DuplicateLabel l expr) =

589 renderSimpleErrorMessage (DuplicateLabel l expr) =

586− paras $ [ line $ "Duplicate label " ++ show l ++ " in row." ]

590+ paras $ [ line $ "The duplicate label " ++ show l ++ " appears in a row type." ]

587 <> foldMap (\expr' -> [ line "Relevant expression: "

591 <> foldMap (\expr' -> [ line "Relevant expression: "

588 , indent $ prettyPrintValue expr'

592 , indent $ prettyPrintValue expr'

589 ]) expr

593 ]) expr

590 renderSimpleErrorMessage (DuplicateTypeArgument name) =

594 renderSimpleErrorMessage (DuplicateTypeArgument name) =

591− line $ "Duplicate type argument " ++ show name

595+ line $ "The type argument " ++ show name ++ " appears more than once."

592 renderSimpleErrorMessage (DuplicateValueDeclaration nm) =

596 renderSimpleErrorMessage (DuplicateValueDeclaration nm) =

593− line $ "Duplicate value declaration for " ++ showIdent nm

597+ line $ "Multiple value declarations exist for " ++ showIdent nm ++ "."

594 renderSimpleErrorMessage (ArgListLengthsDiffer ident) =

598 renderSimpleErrorMessage (ArgListLengthsDiffer ident) =

595 line $ "Argument list lengths differ in declaration " ++ showIdent ident

599 line $ "Argument list lengths differ in declaration " ++ showIdent ident

596 renderSimpleErrorMessage (OverlappingArgNames ident) =

600 renderSimpleErrorMessage (OverlappingArgNames ident) =

597 line $ "Overlapping names in function/binder" ++ foldMap ((" in declaration" ++) . showIdent) ident

601 line $ "Overlapping names in function/binder" ++ foldMap ((" in declaration" ++) . showIdent) ident

598 renderSimpleErrorMessage (MissingClassMember ident) =

602 renderSimpleErrorMessage (MissingClassMember ident) =

599− line $ "Member " ++ showIdent ident ++ " has not been implemented"

603+ line $ "The type class member " ++ showIdent ident ++ " has not been implemented."

600− renderSimpleErrorMessage (ExtraneousClassMember ident) =

604+ renderSimpleErrorMessage (ExtraneousClassMember ident className) =

601− line $ "Member " ++ showIdent ident ++ " is not a member of the class being instantiated"

605+ line $ showIdent ident ++ " is not a member of type class " ++ showQualified runProperName className

602 renderSimpleErrorMessage (ExpectedType ty kind) =

606 renderSimpleErrorMessage (ExpectedType ty kind) =

603 paras [ line "In a type-annotated expression x :: t, the type t must have kind *."

607 paras [ line "In a type-annotated expression x :: t, the type t must have kind *."

604 , line "The error arises from the type"

608 , line "The error arises from the type"

@@ -608,29 +612,28 @@ prettyPrintSingleError full level e = prettyPrintErrorMessage . positionHintsFir

608 , line "instead."

612 , line "instead."

609 ]

613 ]

610 renderSimpleErrorMessage (IncorrectConstructorArity nm) =

614 renderSimpleErrorMessage (IncorrectConstructorArity nm) =

611− line $ "Wrong number of arguments to constructor " ++ showQualified runProperName nm

615+ line $ "The data constructor " ++ showQualified runProperName nm ++ " was given the wrong number of arguments in a case expression."

612− renderSimpleErrorMessage SubsumptionCheckFailed = line "Unable to check type subsumption"

613 renderSimpleErrorMessage (ExprDoesNotHaveType expr ty) =

616 renderSimpleErrorMessage (ExprDoesNotHaveType expr ty) =

614− paras [ line "Expression"

617+ paras [ line "The expression"

615 , indent $ prettyPrintValue expr

618 , indent $ prettyPrintValue expr

616 , line "does not have type"

619 , line "does not have type"

617 , indent $ typeAsBox ty

620 , indent $ typeAsBox ty

618 ]

621 ]

619 renderSimpleErrorMessage (PropertyIsMissing prop row) =

622 renderSimpleErrorMessage (PropertyIsMissing prop row) =

620− paras [ line "Row"

623+ paras [ line "The row type"

621 , indent $ prettyPrintRowWith '(' ')' row

624 , indent $ prettyPrintRowWith '(' ')' row

622− , line $ "lacks required property " ++ show prop

625+ , line $ "lacks the required property " ++ show prop

623 ]

626 ]

624 renderSimpleErrorMessage (CannotApplyFunction fn arg) =

627 renderSimpleErrorMessage (CannotApplyFunction fn arg) =

625− paras [ line "Cannot apply function of type"

628+ paras [ line "A function of type"

626 , indent $ typeAsBox fn

629 , indent $ typeAsBox fn

627− , line "to argument"

630+ , line "can not be applied to the argument"

628 , indent $ prettyPrintValue arg

631 , indent $ prettyPrintValue arg

629 ]

632 ]

630 renderSimpleErrorMessage TypeSynonymInstance =

633 renderSimpleErrorMessage TypeSynonymInstance =

631− line "Type synonym instances are disallowed"

634+ line "Type class instances for type synonyms are disallowed."

632 renderSimpleErrorMessage (OrphanInstance nm cnm ts) =

635 renderSimpleErrorMessage (OrphanInstance nm cnm ts) =

633− paras [ line $ "Instance " ++ showIdent nm ++ " for "

636+ paras [ line $ "The type class instance " ++ showIdent nm ++ " for "

634 , indent $ Box.hsep 1 Box.left [ line (showQualified runProperName cnm)

637 , indent $ Box.hsep 1 Box.left [ line (showQualified runProperName cnm)

635 , Box.vcat Box.left (map typeAtomAsBox ts)

638 , Box.vcat Box.left (map typeAtomAsBox ts)

636 ]

639 ]

@@ -639,29 +642,31 @@ prettyPrintSingleError full level e = prettyPrintErrorMessage . positionHintsFir

639 , line "Consider moving the instance, if possible, or using a newtype wrapper."

642 , line "Consider moving the instance, if possible, or using a newtype wrapper."

640 ]

643 ]

641 renderSimpleErrorMessage InvalidNewtype =

644 renderSimpleErrorMessage InvalidNewtype =

642− line "Newtypes must define a single constructor with a single argument"

645+ line "Newtypes must define a single constructor with a single argument."

643 renderSimpleErrorMessage (InvalidInstanceHead ty) =

646 renderSimpleErrorMessage (InvalidInstanceHead ty) =

644− paras [ line "Invalid type in class instance head:"

647+ paras [ line "An invalid type appears in a type class instance head:"

645 , indent $ typeAsBox ty

648 , indent $ typeAsBox ty

646 ]

649 ]

647 renderSimpleErrorMessage (TransitiveExportError x ys) =

650 renderSimpleErrorMessage (TransitiveExportError x ys) =

648 paras $ line ("An export for " ++ prettyPrintExport x ++ " requires the following to also be exported: ")

651 paras $ line ("An export for " ++ prettyPrintExport x ++ " requires the following to also be exported: ")

649 : map (line . prettyPrintExport) ys

652 : map (line . prettyPrintExport) ys

650 renderSimpleErrorMessage (ShadowedName nm) =

653 renderSimpleErrorMessage (ShadowedName nm) =

651− line $ "Name '" ++ showIdent nm ++ "' was shadowed"

654+ line $ "The name '" ++ showIdent nm ++ "' was shadowed."

652 renderSimpleErrorMessage (ShadowedTypeVar tv) =

655 renderSimpleErrorMessage (ShadowedTypeVar tv) =

653− line $ "Type variable '" ++ tv ++ "' was shadowed"

656+ line $ "The type variable '" ++ tv ++ "' was shadowed."

654 renderSimpleErrorMessage (UnusedTypeVar tv) =

657 renderSimpleErrorMessage (UnusedTypeVar tv) =

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

658+ line $ "The type variable '" ++ tv ++ "' was declared but not used."

656 renderSimpleErrorMessage (ClassOperator className opName) =

659 renderSimpleErrorMessage (ClassOperator className opName) =

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

660+ paras [ line $ "The type class '" ++ runProperName className ++ "' declares operator " ++ showIdent opName ++ "."

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

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

659 , indent . line $ showIdent opName ++ " = someMember"

662 , indent . line $ showIdent opName ++ " = someMember"

660 ]

663 ]

661 renderSimpleErrorMessage (MisleadingEmptyTypeImport mn name) =

664 renderSimpleErrorMessage (MisleadingEmptyTypeImport mn name) =

662− line $ "Importing type " ++ runProperName name ++ "(..) from " ++ runModuleName mn ++ " is misleading as it has no exported data constructors"

665+ line $ "Importing type " ++ runProperName name ++ "(..) from " ++ runModuleName mn ++ " is misleading as it has no exported data constructors."

663 renderSimpleErrorMessage (ImportHidingModule name) =

666 renderSimpleErrorMessage (ImportHidingModule name) =

667+ paras [ line $ "'hiding' imports cannot be used to hide modules."

664− line $ "Attempted to hide module " ++ runModuleName name ++ " in import expression, this is not permitted"

668+ , line $ "An attempt was made to hide the import of " ++ runModuleName name

669+ ]

665 renderSimpleErrorMessage (WildcardInferredType ty) =

670 renderSimpleErrorMessage (WildcardInferredType ty) =

666 paras [ line "The wildcard type definition has the inferred type "

671 paras [ line "The wildcard type definition has the inferred type "

667 , indent $ typeAsBox ty

672 , indent $ typeAsBox ty

@@ -692,9 +697,9 @@ prettyPrintSingleError full level e = prettyPrintErrorMessage . positionHintsFir

692 renderHint (NotYetDefined names) =

697 renderHint (NotYetDefined names) =

693 line $ "The following are not yet defined here: " ++ intercalate ", " (map showIdent names) ++ ":"

698 line $ "The following are not yet defined here: " ++ intercalate ", " (map showIdent names) ++ ":"

694 renderHint (ErrorUnifyingTypes t1 t2) =

699 renderHint (ErrorUnifyingTypes t1 t2) =

695− paras [ lineWithLevel "unifying type "

700+ paras [ lineWithLevel "while trying to make the type "

696 , indent $ typeAsBox t1

701 , indent $ typeAsBox t1

697− , line "with type"

702+ , line "equal to the type"

698 , indent $ typeAsBox t2

703 , indent $ typeAsBox t2

699 ]

704 ]

700 renderHint (ErrorInExpression expr) =

705 renderHint (ErrorInExpression expr) =

@@ -705,9 +710,9 @@ prettyPrintSingleError full level e = prettyPrintErrorMessage . positionHintsFir

705 paras [ lineWithLevel $ "in module " ++ runModuleName mn ++ ":"

710 paras [ lineWithLevel $ "in module " ++ runModuleName mn ++ ":"

706 ]

711 ]

707 renderHint (ErrorInSubsumption t1 t2) =

712 renderHint (ErrorInSubsumption t1 t2) =

708− paras [ lineWithLevel "checking that type "

713+ paras [ lineWithLevel "checking that the type"

709 , indent $ typeAsBox t1

714 , indent $ typeAsBox t1

710− , line "subsumes type"

715+ , line "is more general than the type"

711 , indent $ typeAsBox t2

716 , indent $ typeAsBox t2

712 ]

717 ]

713 renderHint (ErrorInInstance nm ts) =

718 renderHint (ErrorInInstance nm ts) =

@@ -717,25 +722,25 @@ prettyPrintSingleError full level e = prettyPrintErrorMessage . positionHintsFir

717 ]

722 ]

718 ]

723 ]

719 renderHint (ErrorCheckingKind ty) =

724 renderHint (ErrorCheckingKind ty) =

720− paras [ lineWithLevel "checking kind of type "

725+ paras [ lineWithLevel "checking the kind of the type"

721 , indent $ typeAsBox ty

726 , indent $ typeAsBox ty

722 ]

727 ]

723 renderHint (ErrorInferringType expr) =

728 renderHint (ErrorInferringType expr) =

724− paras [ lineWithLevel "inferring type of value "

729+ paras [ lineWithLevel "inferring the type of the expression"

725 , indent $ prettyPrintValue expr

730 , indent $ prettyPrintValue expr

726 ]

731 ]

727 renderHint (ErrorCheckingType expr ty) =

732 renderHint (ErrorCheckingType expr ty) =

728− paras [ lineWithLevel "checking that value "

733+ paras [ lineWithLevel "checking that the expression"

729 , indent $ prettyPrintValue expr

734 , indent $ prettyPrintValue expr

730− , line "has type"

735+ , line "has the type"

731 , indent $ typeAsBox ty

736 , indent $ typeAsBox ty

732 ]

737 ]

733 renderHint (ErrorInApplication f t a) =

738 renderHint (ErrorInApplication f t a) =

734− paras [ lineWithLevel "applying function"

739+ paras [ lineWithLevel "applying a function"

735 , indent $ prettyPrintValue f

740 , indent $ prettyPrintValue f

736 , line "of type"

741 , line "of type"

737 , indent $ typeAsBox t

742 , indent $ typeAsBox t

738− , line "to argument"

743+ , line "to the argument"

739 , indent $ prettyPrintValue a

744 , indent $ prettyPrintValue a

740 ]

745 ]

741 renderHint (ErrorInDataConstructor nm) =

746 renderHint (ErrorInDataConstructor nm) =

@@ -765,15 +770,6 @@ prettyPrintSingleError full level e = prettyPrintErrorMessage . positionHintsFir

765 Error -> "error"

770 Error -> "error"

766 Warning -> "warning"

771 Warning -> "warning"

767

772

768− suggestions :: SimpleErrorMessage -> [Box.Box]

769− suggestions (ConflictingImport nm im) = [ line $ "Possible fix: hide " ++ show nm ++ " when importing " ++ runModuleName im ++ ":"

770− , indent . line $ "import " ++ runModuleName im ++ " hiding (" ++ nm ++ ")"

771− ]

772− suggestions (TypesDoNotUnify t1 t2)

773− | isObject t1 && isFunction t2 = [line "Note that function composition in PureScript is defined using (<<<)"]

774− | otherwise = []

775− suggestions _ = []

776−

777 paras :: [Box.Box] -> Box.Box

773 paras :: [Box.Box] -> Box.Box

778 paras = Box.vcat Box.left

774 paras = Box.vcat Box.left

779

775

src/Language/PureScript/Sugar/Operators.hs+1−1

@@ -129,7 +129,7 @@ matchOperators ops = parseChains

129 extendChain (BinaryNoParens op l r) = Left l : Right op : extendChain r

130 extendChain other = [Left other]

131 bracketChain :: Chain -> m Expr

132− bracketChain = either (const . throwError . errorMessage $ CannotReorderOperators) return . P.parse (P.buildExpressionParser opTable parseValue <* P.eof) "operator expression"

132+ bracketChain = either (\_ -> error "matchOperators: cannot reorder operators") return . P.parse (P.buildExpressionParser opTable parseValue <* P.eof) "operator expression"

133 opTable = [P.Infix (P.try (parseTicks >>= \op -> return (\t1 t2 -> App (App op t1) t2))) P.AssocLeft]

134 : map (map (\(name, f, a) -> P.Infix (P.try (matchOp name) >> return f) (toAssoc a))) ops

135 ++ [[ P.Infix (P.try (parseOp >>= \ident -> return (\t1 t2 -> App (App (Var ident) t1) t2))) P.AssocLeft ]]

src/Language/PureScript/Sugar/TypeClasses.hs+1−1

@@ -289,7 +289,7 @@ typeInstanceDictionaryDeclaration name mn deps className tys decls =

289

290 memberToValue :: (Functor m, Applicative m, MonadSupply m, MonadError MultipleErrors m) => [(Ident, Type)] -> Declaration -> Desugar m Expr

291 memberToValue tys' (ValueDeclaration ident _ [] (Right val)) = do

292− _ <- maybe (throwError . errorMessage $ ExtraneousClassMember ident) return $ lookup ident tys'

292+ _ <- maybe (throwError . errorMessage $ ExtraneousClassMember ident className) return $ lookup ident tys'

293 return val

294 memberToValue tys' (PositionedDeclaration pos com d) = rethrowWithPosition pos $ do

295 val <- memberToValue tys' d

src/Language/PureScript/TypeChecker/Subsumption.hs+1−1

@@ -50,7 +50,7 @@ subsumes' val ty1 (ForAll ident ty2 sco) =

50 sko <- newSkolemConstant

51 let sk = skolemize ident sko sco' ty2

52 subsumes val ty1 sk

53− Nothing -> throwError . errorMessage $ UnspecifiedSkolemScope

53+ Nothing -> error "subsumes: unspecified skolem scope"

54subsumes' val (TypeApp (TypeApp f1 arg1) ret1) (TypeApp (TypeApp f2 arg2) ret2) | f1 == tyFunction && f2 == tyFunction = do

55 _ <- subsumes Nothing arg2 arg1

56 _ <- subsumes Nothing ret1 ret2

src/Language/PureScript/TypeChecker/Types.hs+4−4

@@ -496,7 +496,7 @@ check' v@(Var var) ty = do

496 ty' <- introduceSkolemScope <=< replaceAllTypeSynonyms <=< replaceTypeWildcards $ ty

497 v' <- subsumes (Just v) repl ty'

498 case v' of

499− Nothing -> throwError . errorMessage $ SubsumptionCheckFailed

499+ Nothing -> error "check: unable to check the subsumes relation."

500 Just v'' -> return $ TypedValue True v'' ty'

501check' (SuperClassDictionary className tys) _ = do

502 {-

@@ -515,7 +515,7 @@ check' (TypedValue checkType val ty1) ty2 = do

515 ty2' <- introduceSkolemScope <=< replaceAllTypeSynonyms <=< replaceTypeWildcards $ ty2

516 val' <- subsumes (Just val) ty1' ty2'

517 case val' of

518− Nothing -> throwError . errorMessage $ SubsumptionCheckFailed

518+ Nothing -> error "check: unable to check the subsumes relation."

519 Just _ -> do

520 val''' <- if checkType then withScopedTypeVars moduleName args (check val ty2') else return val

521 return $ TypedValue checkType val''' ty2'

@@ -557,7 +557,7 @@ check' v@(Constructor c) ty = do

557 repl <- introduceSkolemScope <=< replaceAllTypeSynonyms $ ty1

558 mv <- subsumes (Just v) repl ty

559 case mv of

560− Nothing -> throwError . errorMessage $ SubsumptionCheckFailed

560+ Nothing -> error "check: unable to check the subsumes relation."

561 Just v' -> return $ TypedValue True v' ty

562check' (Let ds val) ty = do

563 (ds', val') <- inferLetBinding [] ds val (`check` ty)

@@ -572,7 +572,7 @@ check' val ty = do

572 TypedValue _ val' ty' <- infer val

573 mt <- subsumes (Just val') ty' ty

574 case mt of

575− Nothing -> throwError . errorMessage $ SubsumptionCheckFailed

575+ Nothing -> error "check: unable to check the subsumes relation."

576 Just v' -> return $ TypedValue True v' ty

577

578-- |

src/Language/PureScript/TypeChecker/Unify.hs+2−2

@@ -74,12 +74,12 @@ unifyTypes t1 t2 = rethrow (addHint (ErrorUnifyingTypes t1 t2)) $

74 let sk1 = skolemize ident1 sko sc1' ty1

75 let sk2 = skolemize ident2 sko sc2' ty2

76 sk1 `unifyTypes` sk2

77− _ -> error "Skolemized type variable was not given a scope"

77+ _ -> error "unifyTypes: unspecified skolem scope"

78 unifyTypes' (ForAll ident ty1 (Just sc)) ty2 = do

79 sko <- newSkolemConstant

80 let sk = skolemize ident sko sc ty1

81 sk `unifyTypes` ty2

82− unifyTypes' ForAll{} _ = throwError . errorMessage $ UnspecifiedSkolemScope

82+ unifyTypes' ForAll{} _ = error "unifyTypes: unspecified skolem scope"

83 unifyTypes' ty f@ForAll{} = f `unifyTypes` ty

84 unifyTypes' (TypeVar v1) (TypeVar v2) | v1 == v2 = return ()

85 unifyTypes' ty1@(TypeConstructor c1) ty2@(TypeConstructor c2) =