-- Copyright (c) 2019 The DAML Authors. All rights reserved. -- SPDX-License-Identifier: Apache-2.0 {-# LANGUAGE DuplicateRecordFields #-} {-# LANGUAGE CPP #-} #include "ghc-api-version.h" -- | Go to the definition of a variable. module Development.IDE.Plugin.CodeAction ( plugin -- * For haskell-language-server , codeAction , codeLens , rulePackageExports , executeAddSignatureCommand ) where import Control.Monad (join, guard) import Development.IDE.Plugin import Development.IDE.GHC.Compat import Development.IDE.Core.Rules import Development.IDE.Core.RuleTypes import Development.IDE.Core.Service import Development.IDE.Core.Shake import Development.IDE.GHC.Error import Development.IDE.GHC.Util import Development.IDE.LSP.Server import Development.IDE.Plugin.CodeAction.PositionIndexed import Development.IDE.Plugin.CodeAction.RuleTypes import Development.IDE.Plugin.CodeAction.Rules import Development.IDE.Types.Location import Development.IDE.Types.Options import Development.Shake (Rules) import qualified Data.HashMap.Strict as Map import qualified Language.Haskell.LSP.Core as LSP import Language.Haskell.LSP.VFS import Language.Haskell.LSP.Messages import Language.Haskell.LSP.Types import qualified Data.Rope.UTF16 as Rope import Data.Aeson.Types (toJSON, fromJSON, Value(..), Result(..)) import Data.Char import Data.Maybe import Data.List.Extra import qualified Data.Text as T import Data.Tuple.Extra ((&&&)) import HscTypes import SrcLoc (sortLocated) import Parser import Text.Regex.TDFA ((=~), (=~~)) import Text.Regex.TDFA.Text() import Outputable (ppr, showSDocUnsafe) import DynFlags (xFlags, FlagSpec(..)) import GHC.LanguageExtensions.Type (Extension) import Data.Function import Control.Arrow ((>>>)) import Data.Functor import Control.Applicative ((<|>)) import Safe (atMay) plugin :: Plugin c plugin = codeActionPluginWithRules rules codeAction <> Plugin mempty setHandlersCodeLens rules :: Rules () rules = rulePackageExports -- | Generate code actions. codeAction :: LSP.LspFuncs c -> IdeState -> TextDocumentIdentifier -> Range -> CodeActionContext -> IO (Either ResponseError [CAResult]) codeAction lsp state (TextDocumentIdentifier uri) _range CodeActionContext{_diagnostics=List xs} = do contents <- LSP.getVirtualFileFunc lsp $ toNormalizedUri uri let text = Rope.toText . (_text :: VirtualFile -> Rope.Rope) <$> contents mbFile = toNormalizedFilePath' <$> uriToFilePath uri (ideOptions, parsedModule, join -> env) <- runAction "CodeAction" state $ (,,) <$> getIdeOptions <*> getParsedModule `traverse` mbFile <*> use GhcSession `traverse` mbFile -- This is quite expensive 0.6-0.7s on GHC pkgExports <- runAction "CodeAction:PackageExports" state $ (useNoFile_ . PackageExports) `traverse` env let dflags = hsc_dflags . hscEnv <$> env pure $ Right [ CACodeAction $ CodeAction title (Just CodeActionQuickFix) (Just $ List [x]) (Just edit) Nothing | x <- xs, (title, tedit) <- suggestAction dflags (fromMaybe mempty pkgExports) ideOptions ( join parsedModule ) text x , let edit = WorkspaceEdit (Just $ Map.singleton uri $ List tedit) Nothing ] -- | Generate code lenses. codeLens :: LSP.LspFuncs c -> IdeState -> CodeLensParams -> IO (Either ResponseError (List CodeLens)) codeLens _lsp ideState CodeLensParams{_textDocument=TextDocumentIdentifier uri} = do commandId <- makeLspCommandId "typesignature.add" fmap (Right . List) $ case uriToFilePath' uri of Just (toNormalizedFilePath' -> filePath) -> do _ <- runAction "codeLens" ideState (use TypeCheck filePath) diag <- getDiagnostics ideState hDiag <- getHiddenDiagnostics ideState pure [ CodeLens _range (Just (Command title commandId (Just $ List [toJSON edit]))) Nothing | (dFile, _, dDiag@Diagnostic{_range=_range}) <- diag ++ hDiag , dFile == filePath , (title, tedit) <- suggestSignature False dDiag , let edit = WorkspaceEdit (Just $ Map.singleton uri $ List tedit) Nothing ] Nothing -> pure [] -- | Execute the "typesignature.add" command. executeAddSignatureCommand :: LSP.LspFuncs c -> IdeState -> ExecuteCommandParams -> IO (Either ResponseError Value, Maybe (ServerMethod, ApplyWorkspaceEditParams)) executeAddSignatureCommand _lsp _ideState ExecuteCommandParams{..} -- _command is prefixed with a process ID, because certain clients -- have a global command registry, and all commands must be -- unique. And there can be more than one ghcide instance running -- at a time against the same client. | T.isSuffixOf "typesignature.add" _command , Just (List [edit]) <- _arguments , Success wedit <- fromJSON edit = return (Right Null, Just (WorkspaceApplyEdit, ApplyWorkspaceEditParams wedit)) | otherwise = return (Right Null, Nothing) suggestAction :: Maybe DynFlags -> PackageExportsMap -> IdeOptions -> Maybe ParsedModule -> Maybe T.Text -> Diagnostic -> [(T.Text, [TextEdit])] suggestAction dflags packageExports ideOptions parsedModule text diag = concat [ suggestAddExtension diag , suggestExtendImport dflags text diag , suggestFillHole diag , suggestFillTypeWildcard diag , suggestFixConstructorImport text diag , suggestModuleTypo diag , suggestReplaceIdentifier text diag , suggestSignature True diag , suggestConstraint text diag , removeRedundantConstraints text diag , suggestAddTypeAnnotationToSatisfyContraints text diag ] ++ concat [ suggestNewDefinition ideOptions pm text diag ++ suggestRemoveRedundantImport pm text diag ++ suggestNewImport packageExports pm diag ++ suggestDeleteTopBinding pm diag ++ suggestExportUnusedTopBinding text pm diag | Just pm <- [parsedModule]] suggestRemoveRedundantImport :: ParsedModule -> Maybe T.Text -> Diagnostic -> [(T.Text, [TextEdit])] suggestRemoveRedundantImport ParsedModule{pm_parsed_source = L _ HsModule{hsmodImports}} contents Diagnostic{_range=_range,..} -- The qualified import of ‘many’ from module ‘Control.Applicative’ is redundant | Just [_, bindings] <- matchRegex _message "The( qualified)? import of ‘([^’]*)’ from module [^ ]* is redundant" , Just (L _ impDecl) <- find (\(L l _) -> srcSpanToRange l == _range ) hsmodImports , Just c <- contents , ranges <- map (rangesForBinding impDecl . T.unpack) (T.splitOn ", " bindings) , ranges' <- extendAllToIncludeCommaIfPossible (indexedByPosition $ T.unpack c) (concat ranges) , not (null ranges') = [( "Remove " <> bindings <> " from import" , [ TextEdit r "" | r <- ranges' ] )] -- File.hs:16:1: warning: -- The import of `Data.List' is redundant -- except perhaps to import instances from `Data.List' -- To import instances alone, use: import Data.List() | _message =~ ("The( qualified)? import of [^ ]* is redundant" :: String) = [("Remove import", [TextEdit (extendToWholeLineIfPossible contents _range) ""])] | otherwise = [] suggestDeleteTopBinding :: ParsedModule -> Diagnostic -> [(T.Text, [TextEdit])] suggestDeleteTopBinding ParsedModule{pm_parsed_source = L _ HsModule{hsmodDecls}} Diagnostic{_range=_range,..} -- Foo.hs:4:1: warning: [-Wunused-top-binds] Defined but not used: ‘f’ | Just [name] <- matchRegex _message ".*Defined but not used: ‘([^ ]+)’" , let allTopLevel = filter (isTopLevel . fst) . map (\(L l b) -> (srcSpanToRange l, b)) . sortLocated $ hsmodDecls sameName = filter (matchesBindingName (T.unpack name) . snd) allTopLevel , not (null sameName) = [("Delete ‘" <> name <> "’", flip TextEdit "" . toNextBinding allTopLevel . fst <$> sameName )] | otherwise = [] where isTopLevel l = (_character . _start) l == 0 forwardLines lines r = r {_end = (_end r) {_line = (_line . _end $ r) + lines, _character = 0}} toNextBinding bindings r@Range { _end = Position {_line = l} } | Just (Range { _start = Position {_line = l'}}, _) <- find ((> l) . _line . _start . fst) bindings = forwardLines (l' - l) r toNextBinding _ r = r matchesBindingName :: String -> HsDecl GhcPs -> Bool matchesBindingName b (ValD FunBind {fun_id=L _ x}) = showSDocUnsafe (ppr x) == b matchesBindingName b (SigD (TypeSig (L _ x:_) _)) = showSDocUnsafe (ppr x) == b matchesBindingName _ _ = False data ExportsAs = ExportName | ExportPattern | ExportAll deriving (Eq) suggestExportUnusedTopBinding :: Maybe T.Text -> ParsedModule -> Diagnostic -> [(T.Text, [TextEdit])] suggestExportUnusedTopBinding srcOpt ParsedModule{pm_parsed_source = L _ HsModule{..}} Diagnostic{..} -- Foo.hs:4:1: warning: [-Wunused-top-binds] Defined but not used: ‘f’ -- Foo.hs:5:1: warning: [-Wunused-top-binds] Defined but not used: type constructor or class ‘F’ -- Foo.hs:6:1: warning: [-Wunused-top-binds] Defined but not used: data constructor ‘Bar’ | Just source <- srcOpt , Just [name] <- matchRegex _message ".*Defined but not used: ‘([^ ]+)’" <|> matchRegex _message ".*Defined but not used: type constructor or class ‘([^ ]+)’" <|> matchRegex _message ".*Defined but not used: data constructor ‘([^ ]+)’" , Just (exportType, _) <- find (matchWithDiagnostic _range . snd) . mapMaybe (\(L l b) -> if isTopLevel $ srcSpanToRange l then exportsAs b else Nothing) $ hsmodDecls , Just pos <- _end . getLocatedRange <$> hsmodExports , Just needComma <- needsComma source <$> hsmodExports , let exportName = (if needComma then "," else "") <> printExport exportType name insertPos = pos {_character = pred $ _character pos} = [("Export ‘" <> name <> "’", [TextEdit (Range insertPos insertPos) exportName])] | otherwise = [] where -- we get the last export and the closing bracket and check for comma in that range needsComma :: T.Text -> Located [LIE GhcPs] -> Bool needsComma _ (L _ []) = False needsComma source x@(L _ exports) = let closeParan = _end $ getLocatedRange x lastExport = _end . getLocatedRange $ last exports in not $ T.isInfixOf "," $ textInRange (Range lastExport closeParan) source getLocatedRange :: Located a -> Range getLocatedRange = srcSpanToRange . getLoc matchWithDiagnostic :: Range -> Located (IdP GhcPs) -> Bool matchWithDiagnostic Range{_start=l,_end=r} x = let loc = _start . getLocatedRange $ x in loc >= l && loc <= r printExport :: ExportsAs -> T.Text -> T.Text printExport ExportName x = x printExport ExportPattern x = "pattern " <> x printExport ExportAll x = x <> "(..)" isTopLevel :: Range -> Bool isTopLevel l = (_character . _start) l == 0 exportsAs :: HsDecl p -> Maybe (ExportsAs, Located (IdP p)) exportsAs (ValD FunBind {fun_id}) = Just (ExportName, fun_id) exportsAs (ValD (PatSynBind PSB {psb_id})) = Just (ExportPattern, psb_id) exportsAs (TyClD SynDecl{tcdLName}) = Just (ExportName, tcdLName) exportsAs (TyClD DataDecl{tcdLName}) = Just (ExportAll, tcdLName) exportsAs (TyClD ClassDecl{tcdLName}) = Just (ExportAll, tcdLName) exportsAs (TyClD FamDecl{tcdFam}) = Just (ExportAll, fdLName tcdFam) exportsAs _ = Nothing suggestAddTypeAnnotationToSatisfyContraints :: Maybe T.Text -> Diagnostic -> [(T.Text, [TextEdit])] suggestAddTypeAnnotationToSatisfyContraints sourceOpt Diagnostic{_range=_range,..} -- File.hs:52:41: warning: -- * Defaulting the following constraint to type ‘Integer’ -- Num p0 arising from the literal ‘1’ -- * In the expression: 1 -- In an equation for ‘f’: f = 1 -- File.hs:52:41: warning: -- * Defaulting the following constraints to type ‘[Char]’ -- (Show a0) -- arising from a use of ‘traceShow’ -- at A.hs:228:7-25 -- (IsString a0) -- arising from the literal ‘"debug"’ -- at A.hs:228:17-23 -- * In the expression: traceShow "debug" a -- In an equation for ‘f’: f a = traceShow "debug" a -- File.hs:52:41: warning: -- * Defaulting the following constraints to type ‘[Char]’ -- (Show a0) -- arising from a use of ‘traceShow’ -- at A.hs:255:28-43 -- (IsString a0) -- arising from the literal ‘"test"’ -- at /Users/serhiip/workspace/ghcide/src/Development/IDE/Plugin/CodeAction.hs:255:38-43 -- * In the fourth argument of ‘seq’, namely ‘(traceShow "test")’ -- In the expression: seq "test" seq "test" (traceShow "test") -- In an equation for ‘f’: -- f = seq "test" seq "test" (traceShow "test") | Just [ty, lit] <- matchRegex _message (pat False False True) <|> matchRegex _message (pat False False False) = codeEdit ty lit (makeAnnotatedLit ty lit) | Just source <- sourceOpt , Just [ty, lit] <- matchRegex _message (pat True True False) = let lit' = makeAnnotatedLit ty lit; tir = textInRange _range source in codeEdit ty lit (T.replace lit lit' tir) | otherwise = [] where makeAnnotatedLit ty lit = "(" <> lit <> " :: " <> ty <> ")" pat multiple at inThe = T.concat [ ".*Defaulting the following constraint" , if multiple then "s" else "" , " to type ‘([^ ]+)’ " , ".*arising from the literal ‘(.+)’" , if inThe then ".+In the.+argument" else "" , if at then ".+at" else "" , ".+In the expression" ] codeEdit ty lit replacement = let title = "Add type annotation ‘" <> ty <> "’ to ‘" <> lit <> "’" edits = [TextEdit _range replacement] in [( title, edits )] suggestReplaceIdentifier :: Maybe T.Text -> Diagnostic -> [(T.Text, [TextEdit])] suggestReplaceIdentifier contents Diagnostic{_range=_range,..} -- File.hs:52:41: error: -- * Variable not in scope: -- suggestAcion :: Maybe T.Text -> Range -> Range -- * Perhaps you meant ‘suggestAction’ (line 83) -- File.hs:94:37: error: -- Not in scope: ‘T.isPrfixOf’ -- Perhaps you meant one of these: -- ‘T.isPrefixOf’ (imported from Data.Text), -- ‘T.isInfixOf’ (imported from Data.Text), -- ‘T.isSuffixOf’ (imported from Data.Text) -- Module ‘Data.Text’ does not export ‘isPrfixOf’. | renameSuggestions@(_:_) <- extractRenamableTerms _message = [ ("Replace with ‘" <> name <> "’", [mkRenameEdit contents _range name]) | name <- renameSuggestions ] | otherwise = [] suggestNewDefinition :: IdeOptions -> ParsedModule -> Maybe T.Text -> Diagnostic -> [(T.Text, [TextEdit])] suggestNewDefinition ideOptions parsedModule contents Diagnostic{_message, _range} -- * Variable not in scope: -- suggestAcion :: Maybe T.Text -> Range -> Range | Just [name, typ] <- matchRegex message "Variable not in scope: ([^ ]+) :: ([^*•]+)" = newDefinitionAction ideOptions parsedModule _range name typ | Just [name, typ] <- matchRegex message "Found hole: _([^ ]+) :: ([^*•]+) Or perhaps" , [(label, newDefinitionEdits)] <- newDefinitionAction ideOptions parsedModule _range name typ = [(label, mkRenameEdit contents _range name : newDefinitionEdits)] | otherwise = [] where message = unifySpaces _message newDefinitionAction :: IdeOptions -> ParsedModule -> Range -> T.Text -> T.Text -> [(T.Text, [TextEdit])] newDefinitionAction IdeOptions{..} parsedModule Range{_start} name typ | Range _ lastLineP : _ <- [ srcSpanToRange l | (L l _) <- hsmodDecls , _start `isInsideSrcSpan` l] , nextLineP <- Position{ _line = _line lastLineP + 1, _character = 0} = [ ("Define " <> sig , [TextEdit (Range nextLineP nextLineP) (T.unlines ["", sig, name <> " = error \"not implemented\""])] )] | otherwise = [] where colon = if optNewColonConvention then " : " else " :: " sig = name <> colon <> T.dropWhileEnd isSpace typ ParsedModule{pm_parsed_source = L _ HsModule{hsmodDecls}} = parsedModule suggestFillTypeWildcard :: Diagnostic -> [(T.Text, [TextEdit])] suggestFillTypeWildcard Diagnostic{_range=_range,..} -- Foo.hs:3:8: error: -- * Found type wildcard `_' standing for `p -> p1 -> p' | "Found type wildcard" `T.isInfixOf` _message , " standing for " `T.isInfixOf` _message , typeSignature <- extractWildCardTypeSignature _message = [("Use type signature: ‘" <> typeSignature <> "’", [TextEdit _range typeSignature])] | otherwise = [] suggestAddExtension :: Diagnostic -> [(T.Text, [TextEdit])] suggestAddExtension Diagnostic{_range=_range,..} -- File.hs:22:8: error: -- Illegal lambda-case (use -XLambdaCase) -- File.hs:22:6: error: -- Illegal view pattern: x -> foo -- Use ViewPatterns to enable view patterns -- File.hs:26:8: error: -- Illegal `..' in record pattern -- Use RecordWildCards to permit this -- File.hs:53:28: error: -- Illegal tuple section: use TupleSections -- File.hs:238:29: error: -- * Can't make a derived instance of `Data FSATrace': -- You need DeriveDataTypeable to derive an instance for this class -- * In the data declaration for `FSATrace' -- C:\Neil\shake\src\Development\Shake\Command.hs:515:31: error: -- * Illegal equational constraint a ~ () -- (Use GADTs or TypeFamilies to permit this) -- * In the context: a ~ () -- While checking an instance declaration -- In the instance declaration for `Unit (m a)' | exts@(_:_) <- filter (`Map.member` ghcExtensions) $ T.split (not . isAlpha) $ T.replace "-X" "" _message = [("Add " <> x <> " extension", [TextEdit (Range (Position 0 0) (Position 0 0)) $ "{-# LANGUAGE " <> x <> " #-}\n"]) | x <- exts] | otherwise = [] -- | All the GHC extensions ghcExtensions :: Map.HashMap T.Text Extension ghcExtensions = Map.fromList . filter notStrictFlag . map ( ( T.pack . flagSpecName ) &&& flagSpecFlag ) $ xFlags where -- Strict often causes false positives, as in Data.Map.Strict imports. -- See discussion at https://github.com/digital-asset/ghcide/pull/638 notStrictFlag (name, _) = name /= "Strict" suggestModuleTypo :: Diagnostic -> [(T.Text, [TextEdit])] suggestModuleTypo Diagnostic{_range=_range,..} -- src/Development/IDE/Core/Compile.hs:58:1: error: -- Could not find module ‘Data.Cha’ -- Perhaps you meant Data.Char (from base-4.12.0.0) | "Could not find module" `T.isInfixOf` _message , "Perhaps you meant" `T.isInfixOf` _message = let findSuggestedModules = map (head . T.words) . drop 2 . T.lines proposeModule mod = ("replace with " <> mod, [TextEdit _range mod]) in map proposeModule $ nubOrd $ findSuggestedModules _message | otherwise = [] suggestFillHole :: Diagnostic -> [(T.Text, [TextEdit])] suggestFillHole Diagnostic{_range=_range,..} -- ...Development/IDE/LSP/CodeAction.hs:103:9: warning: -- * Found hole: _ :: Int -> String -- * In the expression: _ -- In the expression: _ a -- In an equation for ‘foo’: foo a = _ a -- * Relevant bindings include -- a :: Int -- (bound at ...Development/IDE/LSP/CodeAction.hs:103:5) -- foo :: Int -> String -- (bound at ...Development/IDE/LSP/CodeAction.hs:103:1) -- Valid hole fits include -- foo :: Int -> String -- (bound at ...Development/IDE/LSP/CodeAction.hs:103:1) -- show :: forall a. Show a => a -> String -- with show @Int -- (imported from ‘Prelude’ at ...Development/IDE/LSP/CodeAction.hs:7:8-37 -- (and originally defined in ‘GHC.Show’)) -- mempty :: forall a. Monoid a => a -- with mempty @(Int -> String) -- (imported from ‘Prelude’ at ...Development/IDE/LSP/CodeAction.hs:7:8-37 -- (and originally defined in ‘GHC.Base’)) (lsp-ui) | topOfHoleFitsMarker `T.isInfixOf` _message = let findSuggestedHoleFits :: T.Text -> [T.Text] findSuggestedHoleFits = extractFitNames . selectLinesWithFits . dropPreceding . T.lines proposeHoleFit name = ("replace hole `" <> holeName <> "` with " <> name, [TextEdit _range name]) holeName = T.strip $ last $ T.splitOn ":" $ head . T.splitOn "::" $ head $ filter ("Found hole" `T.isInfixOf`) $ T.lines _message dropPreceding = dropWhile (not . (topOfHoleFitsMarker `T.isInfixOf`)) selectLinesWithFits = filter ("::" `T.isInfixOf`) extractFitNames = map (T.strip . head . T.splitOn " :: ") in map proposeHoleFit $ nubOrd $ findSuggestedHoleFits _message | otherwise = [] suggestExtendImport :: Maybe DynFlags -> Maybe T.Text -> Diagnostic -> [(T.Text, [TextEdit])] suggestExtendImport (Just dflags) contents Diagnostic{_range=_range,..} | Just [binding, mod, srcspan] <- matchRegex _message "Perhaps you want to add ‘([^’]*)’ to the import list in the import of ‘([^’]*)’ *\\((.*)\\).$" , Just c <- contents , POk _ (L _ name) <- runParser dflags (T.unpack binding) parseIdentifier = let range = case [ x | (x,"") <- readSrcSpan (T.unpack srcspan)] of [s] -> let x = srcSpanToRange s in x{_end = (_end x){_character = succ (_character (_end x))}} _ -> error "bug in srcspan parser" importLine = textInRange range c in [("Add " <> binding <> " to the import list of " <> mod , [TextEdit range (addBindingToImportList (T.pack $ printRdrName name) importLine)])] | otherwise = [] suggestExtendImport Nothing _ _ = [] suggestFixConstructorImport :: Maybe T.Text -> Diagnostic -> [(T.Text, [TextEdit])] suggestFixConstructorImport _ Diagnostic{_range=_range,..} -- ‘Success’ is a data constructor of ‘Result’ -- To import it use -- import Data.Aeson.Types( Result( Success ) ) -- or -- import Data.Aeson.Types( Result(..) ) (lsp-ui) | Just [constructor, typ] <- matchRegex _message "‘([^’]*)’ is a data constructor of ‘([^’]*)’ To import it use" = let fixedImport = typ <> "(" <> constructor <> ")" in [("Fix import of " <> fixedImport, [TextEdit _range fixedImport])] | otherwise = [] suggestSignature :: Bool -> Diagnostic -> [(T.Text, [TextEdit])] suggestSignature isQuickFix Diagnostic{_range=_range@Range{..},..} | _message =~ ("(Top-level binding|Polymorphic local binding|Pattern synonym) with no type signature" :: T.Text) = let signature = removeInitialForAll $ T.takeWhile (\x -> x/='*' && x/='•') $ T.strip $ unifySpaces $ last $ T.splitOn "type signature: " $ filterNewlines _message startOfLine = Position (_line _start) startCharacter beforeLine = Range startOfLine startOfLine title = if isQuickFix then "add signature: " <> signature else signature action = TextEdit beforeLine $ signature <> "\n" <> T.replicate startCharacter " " in [(title, [action])] where removeInitialForAll :: T.Text -> T.Text removeInitialForAll (T.breakOnEnd " :: " -> (nm, ty)) | "forall" `T.isPrefixOf` ty = nm <> T.drop 2 (snd (T.breakOn "." ty)) | otherwise = nm <> ty startCharacter | "Polymorphic local binding" `T.isPrefixOf` _message = _character _start | otherwise = 0 suggestSignature _ _ = [] -- | Suggests a constraint for a declaration for which a constraint is missing. suggestConstraint :: Maybe T.Text -> Diagnostic -> [(T.Text, [TextEdit])] suggestConstraint mContents diag@Diagnostic {..} | Just contents <- mContents , Just missingConstraint <- findMissingConstraint _message = let codeAction = if _message =~ ("the type signature for:" :: String) then suggestFunctionConstraint else suggestInstanceConstraint in codeAction contents diag missingConstraint | otherwise = [] where findMissingConstraint :: T.Text -> Maybe T.Text findMissingConstraint t = let regex = "(No instance for|Could not deduce) \\((.+)\\) arising from a use of" in matchRegex t regex <&> last normalizeConstraints :: T.Text -> T.Text -> T.Text normalizeConstraints existingConstraints constraint = let constraintsInit = if "(" `T.isPrefixOf` existingConstraints then T.dropEnd 1 existingConstraints else "(" <> existingConstraints in constraintsInit <> ", " <> constraint <> ")" -- | Suggests a constraint for an instance declaration for which a constraint is missing. suggestInstanceConstraint :: T.Text -> Diagnostic -> T.Text -> [(T.Text, [TextEdit])] suggestInstanceConstraint contents Diagnostic {..} missingConstraint -- Suggests a constraint for an instance declaration with no existing constraints. -- • No instance for (Eq a) arising from a use of ‘==’ -- Possible fix: add (Eq a) to the context of the instance declaration -- • In the expression: x == y -- In an equation for ‘==’: (Wrap x) == (Wrap y) = x == y -- In the instance declaration for ‘Eq (Wrap a)’ | Just [instanceDeclaration] <- matchRegex _message "In the instance declaration for ‘([^`]*)’" = let instanceLine = contents & T.splitOn ("instance " <> instanceDeclaration) & head & T.lines & length startOfConstraint = Position instanceLine (length ("instance " :: String)) range = Range startOfConstraint startOfConstraint newConstraint = missingConstraint <> " => " in [(actionTitle missingConstraint, [TextEdit range newConstraint])] -- Suggests a constraint for an instance declaration with one or more existing constraints. -- • Could not deduce (Eq b) arising from a use of ‘==’ -- from the context: Eq a -- bound by the instance declaration at /path/to/Main.hs:7:10-32 -- Possible fix: add (Eq b) to the context of the instance declaration -- • In the second argument of ‘(&&)’, namely ‘x' == y'’ -- In the expression: x == y && x' == y' -- In an equation for ‘==’: -- (Pair x x') == (Pair y y') = x == y && x' == y' | Just [instanceLineStr, constraintFirstCharStr] <- matchRegex _message "bound by the instance declaration at .+:([0-9]+):([0-9]+)" = let existingConstraints = findExistingConstraints _message newConstraints = normalizeConstraints existingConstraints missingConstraint instanceLine = readPositionNumber instanceLineStr constraintFirstChar = readPositionNumber constraintFirstCharStr startOfConstraint = Position instanceLine constraintFirstChar endOfConstraint = Position instanceLine $ constraintFirstChar + T.length existingConstraints range = Range startOfConstraint endOfConstraint in [(actionTitle missingConstraint, [TextEdit range newConstraints])] | otherwise = [] where findExistingConstraints :: T.Text -> T.Text findExistingConstraints t = T.replace "from the context: " "" . T.strip $ T.lines t !! 1 readPositionNumber :: T.Text -> Int readPositionNumber = T.unpack >>> read >>> pred actionTitle :: T.Text -> T.Text actionTitle constraint = "Add `" <> constraint <> "` to the context of the instance declaration" findTypeSignatureName :: T.Text -> Maybe T.Text findTypeSignatureName t = matchRegex t "([^ ]+) :: " <&> head findTypeSignatureLine :: T.Text -> T.Text -> Int findTypeSignatureLine contents typeSignatureName = T.splitOn (typeSignatureName <> " :: ") contents & head & T.lines & length -- | Suggests a constraint for a type signature for which a constraint is missing. suggestFunctionConstraint :: T.Text -> Diagnostic -> T.Text -> [(T.Text, [TextEdit])] suggestFunctionConstraint contents Diagnostic{..} missingConstraint -- Suggests a constraint for a type signature with any number of existing constraints. -- • No instance for (Eq a) arising from a use of ‘==’ -- Possible fix: -- add (Eq a) to the context of -- the type signature for: -- eq :: forall a. a -> a -> Bool -- • In the expression: x == y -- In an equation for ‘eq’: eq x y = x == y -- • Could not deduce (Eq b) arising from a use of ‘==’ -- from the context: Eq a -- bound by the type signature for: -- eq :: forall a b. Eq a => Pair a b -> Pair a b -> Bool -- at Main.hs:5:1-42 -- Possible fix: -- add (Eq b) to the context of -- the type signature for: -- eq :: forall a b. Eq a => Pair a b -> Pair a b -> Bool -- • In the second argument of ‘(&&)’, namely ‘y == y'’ -- In the expression: x == x' && y == y' -- In an equation for ‘eq’: -- eq (Pair x y) (Pair x' y') = x == x' && y == y' | Just typeSignatureName <- findTypeSignatureName _message = let mExistingConstraints = findExistingConstraints _message newConstraint = buildNewConstraints missingConstraint mExistingConstraints typeSignatureLine = findTypeSignatureLine contents typeSignatureName typeSignatureFirstChar = T.length $ typeSignatureName <> " :: " startOfConstraint = Position typeSignatureLine typeSignatureFirstChar endOfConstraint = Position typeSignatureLine $ typeSignatureFirstChar + maybe 0 T.length mExistingConstraints range = Range startOfConstraint endOfConstraint in [(actionTitle missingConstraint typeSignatureName, [TextEdit range newConstraint])] | otherwise = [] where findExistingConstraints :: T.Text -> Maybe T.Text findExistingConstraints message = if message =~ ("from the context:" :: String) then fmap (T.strip . head) $ matchRegex message "\\. ([^=]+)" else Nothing buildNewConstraints :: T.Text -> Maybe T.Text -> T.Text buildNewConstraints constraint mExistingConstraints = case mExistingConstraints of Just existingConstraints -> normalizeConstraints existingConstraints constraint Nothing -> constraint <> " => " actionTitle :: T.Text -> T.Text -> T.Text actionTitle constraint typeSignatureName = "Add `" <> constraint <> "` to the context of the type signature for `" <> typeSignatureName <> "`" -- | Suggests the removal of a redundant constraint for a type signature. removeRedundantConstraints :: Maybe T.Text -> Diagnostic -> [(T.Text, [TextEdit])] removeRedundantConstraints mContents Diagnostic{..} -- • Redundant constraint: Eq a -- • In the type signature for: -- foo :: forall a. Eq a => a -> a -- • Redundant constraints: (Monoid a, Show a) -- • In the type signature for: -- foo :: forall a. (Num a, Monoid a, Eq a, Show a) => a -> Bool | Just contents <- mContents -- Account for both "Redundant constraint" and "Redundant constraints". , True <- "Redundant constraint" `T.isInfixOf` _message , Just typeSignatureName <- findTypeSignatureName _message , Just redundantConstraintList <- findRedundantConstraints _message , Just constraints <- findConstraints contents typeSignatureName = let constraintList = parseConstraints constraints newConstraints = buildNewConstraints constraintList redundantConstraintList typeSignatureLine = findTypeSignatureLine contents typeSignatureName typeSignatureFirstChar = T.length $ typeSignatureName <> " :: " startOfConstraint = Position typeSignatureLine typeSignatureFirstChar endOfConstraint = Position typeSignatureLine $ typeSignatureFirstChar + T.length (constraints <> " => ") range = Range startOfConstraint endOfConstraint in [(actionTitle redundantConstraintList typeSignatureName, [TextEdit range newConstraints])] | otherwise = [] where parseConstraints :: T.Text -> [T.Text] parseConstraints t = t & (T.strip >>> stripConstraintsParens >>> T.splitOn ",") <&> T.strip stripConstraintsParens :: T.Text -> T.Text stripConstraintsParens constraints = if "(" `T.isPrefixOf` constraints then constraints & T.drop 1 & T.dropEnd 1 & T.strip else constraints findRedundantConstraints :: T.Text -> Maybe [T.Text] findRedundantConstraints t = t & T.lines & head & T.strip & (`matchRegex` "Redundant constraints?: (.+)") <&> (head >>> parseConstraints) -- If the type signature is not formatted as expected (arbitrary number of spaces, -- line feeds...), just fail. findConstraints :: T.Text -> T.Text -> Maybe T.Text findConstraints contents typeSignatureName = do constraints <- contents & T.splitOn (typeSignatureName <> " :: ") & (`atMay` 1) >>= (T.splitOn " => " >>> (`atMay` 0)) guard $ not $ "\n" `T.isInfixOf` constraints || T.strip constraints /= constraints return constraints formatConstraints :: [T.Text] -> T.Text formatConstraints [] = "" formatConstraints [constraint] = constraint formatConstraints constraintList = constraintList & T.intercalate ", " & \cs -> "(" <> cs <> ")" formatConstraintsWithArrow :: [T.Text] -> T.Text formatConstraintsWithArrow [] = "" formatConstraintsWithArrow cs = cs & formatConstraints & (<> " => ") buildNewConstraints :: [T.Text] -> [T.Text] -> T.Text buildNewConstraints constraintList redundantConstraintList = formatConstraintsWithArrow $ constraintList \\ redundantConstraintList actionTitle :: [T.Text] -> T.Text -> T.Text actionTitle constraintList typeSignatureName = "Remove redundant constraint" <> (if length constraintList == 1 then "" else "s") <> " `" <> formatConstraints constraintList <> "` from the context of the type signature for `" <> typeSignatureName <> "`" ------------------------------------------------------------------------------------------------- suggestNewImport :: PackageExportsMap -> ParsedModule -> Diagnostic -> [(T.Text, [TextEdit])] suggestNewImport packageExportsMap ParsedModule {pm_parsed_source = L _ HsModule {..}} Diagnostic{_message} | msg <- unifySpaces _message , Just name <- extractNotInScopeName msg , Just insertLine <- case hsmodImports of [] -> case srcSpanStart $ getLoc (head hsmodDecls) of RealSrcLoc s -> Just $ srcLocLine s - 1 _ -> Nothing _ -> case srcSpanEnd $ getLoc (last hsmodImports) of RealSrcLoc s -> Just $ srcLocLine s _ -> Nothing , insertPos <- Position insertLine 0 , extendImportSuggestions <- matchRegex msg "Perhaps you want to add ‘[^’]*’ to the import list in the import of ‘([^’]*)’" = [(imp, [TextEdit (Range insertPos insertPos) (imp <> "\n")]) | imp <- constructNewImportSuggestions packageExportsMap name extendImportSuggestions ] suggestNewImport _ _ _ = [] constructNewImportSuggestions :: PackageExportsMap -> NotInScope -> Maybe [T.Text] -> [T.Text] constructNewImportSuggestions exportsMap thingMissing notTheseModules = nubOrd [ renderNewImport identInfo m | (identInfo, m) <- fromMaybe [] $ Map.lookup name exportsMap , canUseIdent thingMissing identInfo , m `notElem` fromMaybe [] notTheseModules ] where renderNewImport identInfo m | Just q <- qual = "import qualified " <> m <> " as " <> q | otherwise = "import " <> m <> " (" <> importWhat identInfo <> ")" (qual, name) = case T.splitOn "." (notInScope thingMissing) of [n] -> (Nothing, n) segments -> (Just (T.concat $ init segments), last segments) importWhat IdentInfo {parent, rendered} | Just p <- parent = p <> "(" <> rendered <> ")" | otherwise = rendered canUseIdent :: NotInScope -> IdentInfo -> Bool canUseIdent NotInScopeDataConstructor{} = isDatacon canUseIdent _ = const True data NotInScope = NotInScopeDataConstructor T.Text | NotInScopeTypeConstructorOrClass T.Text | NotInScopeThing T.Text deriving Show notInScope :: NotInScope -> T.Text notInScope (NotInScopeDataConstructor t) = t notInScope (NotInScopeTypeConstructorOrClass t) = t notInScope (NotInScopeThing t) = t extractNotInScopeName :: T.Text -> Maybe NotInScope extractNotInScopeName x | Just [name] <- matchRegex x "Data constructor not in scope: ([^ ]+)" = Just $ NotInScopeDataConstructor name | Just [name] <- matchRegex x "Not in scope: data constructor [^‘]*‘([^’]*)’" = Just $ NotInScopeDataConstructor name | Just [name] <- matchRegex x "ot in scope: type constructor or class [^‘]*‘([^’]*)’" = Just $ NotInScopeTypeConstructorOrClass name | Just [name] <- matchRegex x "ot in scope: \\(([^‘ ]+)\\)" = Just $ NotInScopeThing name | Just [name] <- matchRegex x "ot in scope: ([^‘ ]+)" = Just $ NotInScopeThing name | Just [name] <- matchRegex x "ot in scope:[^‘]*‘([^’]*)’" = Just $ NotInScopeThing name | otherwise = Nothing ------------------------------------------------------------------------------------------------- topOfHoleFitsMarker :: T.Text topOfHoleFitsMarker = #if MIN_GHC_API_VERSION(8,6,0) "Valid hole fits include" #else "Valid substitutions include" #endif mkRenameEdit :: Maybe T.Text -> Range -> T.Text -> TextEdit mkRenameEdit contents range name = if maybeIsInfixFunction == Just True then TextEdit range ("`" <> name <> "`") else TextEdit range name where maybeIsInfixFunction = do curr <- textInRange range <$> contents pure $ "`" `T.isPrefixOf` curr && "`" `T.isSuffixOf` curr extractWildCardTypeSignature :: T.Text -> T.Text extractWildCardTypeSignature = -- inferring when parens are actually needed around the type signature would -- require understanding both the precedence of the context of the _ and of -- the signature itself. Inserting them unconditionally is ugly but safe. ("(" `T.append`) . (`T.append` ")") . T.takeWhile (/='’') . T.dropWhile (=='‘') . T.dropWhile (/='‘') . snd . T.breakOnEnd "standing for " extractRenamableTerms :: T.Text -> [T.Text] extractRenamableTerms msg -- Account for both "Variable not in scope" and "Not in scope" | "ot in scope:" `T.isInfixOf` msg = extractSuggestions msg | otherwise = [] where extractSuggestions = map getEnclosed . concatMap singleSuggestions . filter isKnownSymbol . T.lines singleSuggestions = T.splitOn "), " -- Each suggestion is comma delimited isKnownSymbol t = " (imported from" `T.isInfixOf` t || " (line " `T.isInfixOf` t getEnclosed = T.dropWhile (== '‘') . T.dropWhileEnd (== '’') . T.dropAround (\c -> c /= '‘' && c /= '’') -- | If a range takes up a whole line (it begins at the start of the line and there's only whitespace -- between the end of the range and the next newline), extend the range to take up the whole line. extendToWholeLineIfPossible :: Maybe T.Text -> Range -> Range extendToWholeLineIfPossible contents range@Range{..} = let newlineAfter = maybe False (T.isPrefixOf "\n" . T.dropWhile (\x -> isSpace x && x /= '\n') . snd . splitTextAtPosition _end) contents extend = newlineAfter && _character _start == 0 -- takes up an entire line, so remove the whole line in if extend then Range _start (Position (_line _end + 1) 0) else range splitTextAtPosition :: Position -> T.Text -> (T.Text, T.Text) splitTextAtPosition (Position row col) x | (preRow, mid:postRow) <- splitAt row $ T.splitOn "\n" x , (preCol, postCol) <- T.splitAt col mid = (T.intercalate "\n" $ preRow ++ [preCol], T.intercalate "\n" $ postCol : postRow) | otherwise = (x, T.empty) -- | Returns [start .. end[ textInRange :: Range -> T.Text -> T.Text textInRange (Range (Position startRow startCol) (Position endRow endCol)) text = case compare startRow endRow of LT -> let (linesInRangeBeforeEndLine, endLineAndFurtherLines) = splitAt (endRow - startRow) linesBeginningWithStartLine (textInRangeInFirstLine, linesBetween) = case linesInRangeBeforeEndLine of [] -> ("", []) firstLine:linesInBetween -> (T.drop startCol firstLine, linesInBetween) maybeTextInRangeInEndLine = T.take endCol <$> listToMaybe endLineAndFurtherLines in T.intercalate "\n" (textInRangeInFirstLine : linesBetween ++ maybeToList maybeTextInRangeInEndLine) EQ -> let line = fromMaybe "" (listToMaybe linesBeginningWithStartLine) in T.take (endCol - startCol) (T.drop startCol line) GT -> "" where linesBeginningWithStartLine = drop startRow (T.splitOn "\n" text) -- | Returns the ranges for a binding in an import declaration rangesForBinding :: ImportDecl GhcPs -> String -> [Range] rangesForBinding ImportDecl{ideclHiding = Just (False, L _ lies)} b = concatMap (map srcSpanToRange . rangesForBinding' b') lies where b' = wrapOperatorInParens (unqualify b) wrapOperatorInParens x = if isAlpha (head x) then x else "(" <> x <> ")" unqualify x = snd $ breakOnEnd "." x rangesForBinding _ _ = [] rangesForBinding' :: String -> LIE GhcPs -> [SrcSpan] rangesForBinding' b (L l x@IEVar{}) | showSDocUnsafe (ppr x) == b = [l] rangesForBinding' b (L l x@IEThingAbs{}) | showSDocUnsafe (ppr x) == b = [l] rangesForBinding' b (L l (IEThingAll x)) | showSDocUnsafe (ppr x) == b = [l] rangesForBinding' b (L l (IEThingWith thing _ inners labels)) | showSDocUnsafe (ppr thing) == b = [l] | otherwise = [ l' | L l' x <- inners, showSDocUnsafe (ppr x) == b] ++ [ l' | L l' x <- labels, showSDocUnsafe (ppr x) == b] rangesForBinding' _ _ = [] -- | Extends an import list with a new binding. -- Assumes an import statement of the form: -- import (qualified) A (..) .. -- Places the new binding first, preserving whitespace. -- Copes with multi-line import lists addBindingToImportList :: T.Text -> T.Text -> T.Text addBindingToImportList binding importLine = case T.breakOn "(" importLine of (pre, T.uncons -> Just (_, rest)) -> case T.uncons (T.dropWhile isSpace rest) of Just (')', _) -> T.concat [pre, "(", binding, rest] _ -> T.concat [pre, "(", binding, ", ", rest] _ -> error $ "importLine does not have the expected structure: " <> T.unpack importLine -- | Returns Just (the submatches) for the first capture, or Nothing. matchRegex :: T.Text -> T.Text -> Maybe [T.Text] matchRegex message regex = case unifySpaces message =~~ regex of Just (_ :: T.Text, _ :: T.Text, _ :: T.Text, bindings) -> Just bindings Nothing -> Nothing setHandlersCodeLens :: PartialHandlers c setHandlersCodeLens = PartialHandlers $ \WithMessage{..} x -> return x{ LSP.codeLensHandler = withResponse RspCodeLens codeLens, LSP.executeCommandHandler = withResponseAndRequest RspExecuteCommand ReqApplyWorkspaceEdit executeAddSignatureCommand } filterNewlines :: T.Text -> T.Text filterNewlines = T.concat . T.lines unifySpaces :: T.Text -> T.Text unifySpaces = T.unwords . T.words