dcce951 · elk · git.iko.soy

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Improve error messages for bad return types (annotation /= def)

dcce951Evan Czaplicki10 years ago

src/Reporting/Error/Helpers.hs+7−1

compare with master

unifiedsplit

@@ -1,7 +1,8 @@

1{-# OPTIONS_GHC -Wall #-}

2module Reporting.Error.Helpers

3 ( (|>)

4+ , functionName, args

4− , functionName, hintLink, stack, reflowParagraph

5+ , hintLink, stack, reflowParagraph

5 , commaSep, capitalize, ordinalize, drawCycle

6 , commaSep, capitalize, ordinalize, drawCycle

6 , findPotentialTypos, findTypoPairs, vetTypos

7 , findPotentialTypos, findTypoPairs, vetTypos

7 , nearbyNames, distance, maybeYouWant

8 , nearbyNames, distance, maybeYouWant

@@ -47,6 +48,11 @@ functionName opName =

47 "`" ++ opName ++ "`"

48 "`" ++ opName ++ "`"

51+args :: Int -> String

52+args n =

53+ show n ++ if n == 1 then " argument" else " arguments"

54+

55+

50hintLink :: String -> String

56hintLink :: String -> String

51hintLink fileName =

57hintLink fileName =

52 "<https://github.com/elm-lang/elm-compiler/blob/"

58 "<https://github.com/elm-lang/elm-compiler/blob/"

src/Reporting/Error/Type.hs+53−26

@@ -69,7 +69,7 @@ data Hint

69 | Function (Maybe Var.Canonical)

70 | UnexpectedArg (Maybe Var.Canonical) Int Int Region.Region

71 | FunctionArity (Maybe Var.Canonical) Int Int Region.Region

72− | ReturnType String Int

72+ | ReturnType String Int Int Region.Region

73 | Instance String

74 | Literal String

75 | Pattern Pattern

@@ -306,7 +306,7 @@ mismatchToReport localizer (MismatchInfo hint leftType rightType maybeReason) =

306 UnexpectedArg maybeName 1 1 region ->

307 report

308 (Just region)

309− ("The argument to " ++ funcName maybeName ++ " is causing a mismatch.")

309+ ("The argument to " ++ funcName maybeName ++ " is causing a mismatch.")

310 ( cmpHint

311 (Help.capitalize (funcName maybeName) ++ " is expecting the argument to be:")

312 "But it is:"

@@ -356,37 +356,34 @@ mismatchToReport localizer (MismatchInfo hint leftType rightType maybeReason) =

356 (text "Maybe you forgot some parentheses? Or a comma?")

357

358 FunctionArity maybeName expected actual region ->

359− let

360− s = if expected == 1 then "" else "s"

361− in

362− report

363− (Just region)

364− ( Help.capitalize (funcName maybeName) ++ " is expecting " ++ show expected

365− ++ " argument" ++ s ++ ", but was given " ++ show actual ++ "."

366− )

367− (text "Maybe you forgot some parentheses? Or a comma?")

368−

369− ReturnType name 0 ->

370 report

359 report

371− Nothing

360+ (Just region)

361+ ( Help.capitalize (funcName maybeName) ++ " is expecting "

362+ ++ Help.args expected ++ ", but was given " ++ show actual ++ "."

363+ )

364+ (text "Maybe you forgot some parentheses? Or a comma?")

365+

366+ ReturnType name typeArity argArity region ->

367+ if typeArity == 0 || argArity == 0 then

368+ report

369+ (Just region)

372− ("The type annotation for " ++ Help.functionName name ++ " does not match its definition.")

370+ ("The definition of " ++ Help.functionName name ++ " does not match its type annotation.")

373 ( cmpHint

371 ( cmpHint

374− ( "The type annotation says " ++ Help.functionName name

372+ ( "The type annotation for " ++ Help.functionName name ++ " says it is a:"

375− ++ " should be a:"

376 )

373 )

377− "But the value you defined has this type:"

374+ "But the definition (shown above) is a:"

378− []

375+ (arityHint typeArity argArity)

379 )

376 )

380

377

381− ReturnType name arity ->

378+ else

382− report

379+ report

383− Nothing

380+ (Just region)

384− ("The " ++ Help.functionName name ++ " function does not match the type annotation.")

381+ ("The definition of " ++ Help.functionName name ++ " does not match its type annotation.")

385 ( cmpHint

382 ( cmpHint

386− "The definition produces values of this type:"

387− ( "But type annotation says " ++ Help.functionName name ++ " should return:"

383+ ( "The type annotation for " ++ Help.functionName name ++ " says it always returns:"

388 )

384 )

389− []

385+ "But the returned value (shown above) is a:"

386+ (arityHint typeArity argArity)

390 )

387 )

391

388

392 Instance name ->

389 Instance name ->

@@ -571,6 +568,36 @@ functionHint maybeName =

571

568

572

569

573

570

571+-- ARITY HINTS

572+

573+

574+arityHint :: Int -> Int -> [String]

575+arityHint typeArity argArity =

576+ if typeArity == argArity then

577+ []

578+

579+ else

580+ [ "The type annotation says there " ++ sayArgs typeArity

581+ ++ ", but there " ++ sayArgs argArity ++ " named in the definition."

582+ ++ " It is best practice for each argument in the type to correspond"

583+ ++ " to a named argument in the definition, so try that first!"

584+ ]

585+

586+

587+sayArgs :: Int -> String

588+sayArgs n =

589+ case n of

590+ 0 ->

591+ "are NO arguments"

592+

593+ 1 ->

594+ "is 1 argument"

595+

596+ _ ->

597+ "are " ++ show n ++ " arguments"

598+

599+

600+

574-- MISMATCH HELPERS

601-- MISMATCH HELPERS

575

602

576

603