Implement signature help #4626
+283
−2
There are no files selected for viewing
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,208 @@ | ||
| {-# LANGUAGE DataKinds #-} | ||
| {-# LANGUAGE GADTs #-} | ||
|
|
||
| module Ide.Plugin.SignatureHelp (descriptor) where | ||
|
|
||
| import Control.Arrow ((>>>)) | ||
| import Data.Bifunctor (bimap) | ||
| import qualified Data.Map.Strict as M | ||
| import Data.Maybe (mapMaybe) | ||
| import qualified Data.Set as S | ||
| import Data.Text (Text) | ||
| import qualified Data.Text as T | ||
| import Development.IDE (GetHieAst (GetHieAst), | ||
| HieAstResult (HAR, hieAst, hieKind), | ||
| HieKind (..), | ||
| IdeState (shakeExtras), | ||
| Pretty (pretty), | ||
| Recorder, WithPriority, | ||
| printOutputable) | ||
| import Development.IDE.Core.PluginUtils (runIdeActionE, | ||
| useWithStaleFastE) | ||
| import Development.IDE.Core.PositionMapping (fromCurrentPosition) | ||
| import Development.IDE.GHC.Compat (ContextInfo (Use), | ||
| FastStringCompat, HieAST, | ||
| HieASTs, | ||
| IdentifierDetails, Name, | ||
| RealSrcSpan, SDoc, | ||
| getAsts, | ||
| getSourceNodeIds, | ||
| hieTypeToIface, | ||
| hie_types, identInfo, | ||
| identType, | ||
| isAnnotationInNodeInfo, | ||
| mkRealSrcLoc, | ||
| mkRealSrcSpan, | ||
| nodeChildren, nodeSpan, | ||
| ppr, recoverFullType, | ||
| smallestContainingSatisfying, | ||
| sourceNodeInfo) | ||
| import Development.IDE.GHC.Compat.Util (LexicalFastString (LexicalFastString)) | ||
| import GHC.Data.Maybe (rightToMaybe) | ||
| import GHC.Types.SrcLoc (isRealSubspanOf) | ||
| import Ide.Plugin.Error (getNormalizedFilePathE) | ||
| import Ide.Types (PluginDescriptor (pluginHandlers), | ||
| PluginId, | ||
| PluginMethodHandler, | ||
| defaultPluginDescriptor, | ||
| mkPluginHandler) | ||
| import Language.LSP.Protocol.Message (Method (Method_TextDocumentSignatureHelp), | ||
| SMethod (SMethod_TextDocumentSignatureHelp)) | ||
| import Language.LSP.Protocol.Types (Null (Null), | ||
| ParameterInformation (ParameterInformation), | ||
| Position (Position), | ||
| SignatureHelp (SignatureHelp), | ||
| SignatureHelpParams (SignatureHelpParams), | ||
| SignatureInformation (SignatureInformation), | ||
| TextDocumentIdentifier (TextDocumentIdentifier), | ||
| UInt, | ||
| type (|?) (InL, InR)) | ||
|
|
||
| data Log = LogDummy | ||
|
|
||
| instance Pretty Log where | ||
| pretty = \case | ||
| LogDummy -> "TODO(@linj) remove this dummy log" | ||
|
|
||
| descriptor :: Recorder (WithPriority Log) -> PluginId -> PluginDescriptor IdeState | ||
| descriptor _recorder pluginId = | ||
| (defaultPluginDescriptor pluginId "Provides signature help of something callable") | ||
| { Ide.Types.pluginHandlers = mkPluginHandler SMethod_TextDocumentSignatureHelp signatureHelpProvider | ||
| } | ||
|
|
||
| -- TODO(@linj) get doc | ||
| signatureHelpProvider :: PluginMethodHandler IdeState Method_TextDocumentSignatureHelp | ||
| signatureHelpProvider ideState _pluginId (SignatureHelpParams (TextDocumentIdentifier uri) position _mProgreeToken _mContext) = do | ||
| nfp <- getNormalizedFilePathE uri | ||
| mResult <- runIdeActionE "signatureHelp" (shakeExtras ideState) $ do | ||
| -- TODO(@linj) why HAR {hieAst} may have more than one AST? | ||
| (HAR {hieAst, hieKind}, positionMapping) <- useWithStaleFastE GetHieAst nfp | ||
| case fromCurrentPosition positionMapping position of | ||
| Nothing -> pure Nothing | ||
| Just oldPosition -> do | ||
| let functionName = | ||
|
There was a problem hiding this comment. you probably want to do all these in one go, this looks like it will traverse the AST three times! I think you can just do one call to |
||
| extractInfoFromSmallestContainingFunctionApplicationAst | ||
| oldPosition | ||
| hieAst | ||
| (\span -> getLeftMostNode >>> getNodeName span) | ||
| functionType = | ||
| extractInfoFromSmallestContainingFunctionApplicationAst | ||
| oldPosition | ||
| hieAst | ||
| (\span -> getLeftMostNode >>> getNodeType hieKind span) | ||
| argumentNumber = | ||
| extractInfoFromSmallestContainingFunctionApplicationAst | ||
| oldPosition | ||
| hieAst | ||
| getArgumentNumber | ||
| pure $ Just (functionName, functionType, argumentNumber) | ||
| case mResult of | ||
| -- TODO(@linj) what do non-singleton lists mean? | ||
| Just (functionName : _, functionType : _, argumentNumber : _) -> do | ||
| pure $ InL $ mkSignatureHelp functionName functionType (fromIntegral argumentNumber - 1) | ||
| _ -> pure $ InR Null | ||
|
|
||
| mkSignatureHelp :: Name -> Text -> UInt -> SignatureHelp | ||
| mkSignatureHelp functionName functionType argumentNumber = | ||
| let functionNameLabelPrefix = printOutputable (ppr functionName) <> " :: " | ||
| in SignatureHelp | ||
| [ SignatureInformation | ||
| (functionNameLabelPrefix <> functionType) | ||
| Nothing | ||
| (Just $ mkArguments (fromIntegral $ T.length functionNameLabelPrefix) functionType) | ||
| (Just $ InL argumentNumber) | ||
| ] | ||
| (Just 0) | ||
| (Just $ InL argumentNumber) | ||
|
There was a problem hiding this comment. do we know if this is 0 or 1-indexed? specification doesn't say (of course 🙄 ) so I guess we'll have to test it in vscode to see |
||
|
|
||
| -- TODO(@linj) can type string be a multi-line string? | ||
| mkArguments :: UInt -> Text -> [ParameterInformation] | ||
|
There was a problem hiding this comment. I think this would be a lot simpler if you were just looking at the type itself! There was a problem hiding this comment. Although hmm, the offsets are into the string 😱 So maybe you would need to incrementally build up the |
||
| mkArguments offset functionType = | ||
| let separator = " -> " | ||
| separatorLength = fromIntegral $ T.length separator | ||
| splits = T.breakOnAll separator functionType | ||
| prefixes = fst <$> splits | ||
| prefixLengths = fmap (T.length >>> fromIntegral) prefixes | ||
| ranges = | ||
| [ ( if previousPrefixLength == 0 then 0 else previousPrefixLength + separatorLength, | ||
| currentPrefixLength | ||
| ) | ||
| | (previousPrefixLength, currentPrefixLength) <- zip (0: prefixLengths) prefixLengths | ||
| ] | ||
| in [ ParameterInformation (InR range) Nothing | ||
| | range <- bimap (+offset) (+offset) <$> ranges | ||
| ] | ||
|
|
||
| extractInfoFromSmallestContainingFunctionApplicationAst :: | ||
| Position -> HieASTs a -> (RealSrcSpan -> HieAST a -> Maybe b) -> [b] | ||
| extractInfoFromSmallestContainingFunctionApplicationAst position hieAsts extractInfo = | ||
| M.elems $ flip M.mapMaybeWithKey (getAsts hieAsts) $ \hiePath hieAst -> | ||
| smallestContainingSatisfying (positionToSpan hiePath position) (nodeHasAnnotation ("HsApp", "HsExpr")) hieAst | ||
| >>= extractInfo (positionToSpan hiePath position) | ||
| where | ||
| positionToSpan hiePath position = | ||
| let loc = mkLoc hiePath position in mkRealSrcSpan loc loc | ||
| mkLoc (LexicalFastString hiePath) (Position line character) = | ||
| mkRealSrcLoc hiePath (fromIntegral line + 1) (fromIntegral character + 1) | ||
|
|
||
| type Annotation = (FastStringCompat, FastStringCompat) | ||
|
|
||
| nodeHasAnnotation :: Annotation -> HieAST a -> Bool | ||
| nodeHasAnnotation annotation = sourceNodeInfo >>> maybe False (isAnnotationInNodeInfo annotation) | ||
|
There was a problem hiding this comment. nit: I think it tends to be easier to read a simple case expression than one of the pattern-matching functions like You can still avoid naming the |
||
|
|
||
| -- TODO(@linj): the left most node may not be the function node. example: (if True then f else g) x | ||
|
There was a problem hiding this comment. this is a great example btw. In this case I think we would have to give no signature help, I think, since it's only dynamically known which function we're getting. |
||
| getLeftMostNode :: HieAST a -> HieAST a | ||
| getLeftMostNode thisNode = | ||
| case nodeChildren thisNode of | ||
| [] -> thisNode | ||
| leftChild: _ -> getLeftMostNode leftChild | ||
|
|
||
| getNodeName :: RealSrcSpan -> HieAST a -> Maybe Name | ||
| getNodeName _span hieAst = | ||
| if nodeHasAnnotation ("HsVar", "HsExpr") hieAst | ||
| then | ||
| case mapMaybe extractName $ M.keys $ M.filter isUse $ getSourceNodeIds hieAst of | ||
| [name] -> Just name -- TODO(@linj) will there be more than one name? | ||
|
There was a problem hiding this comment. I'm not 100% sure when/if this can happen. I think it might happen if we're looking at a typeclass method, in which case we could get the generic typeclass method and the specific one perhaps? That would be a good use-case for multilple signatures, e.g. if we have then we might want to see both the generic There was a problem hiding this comment. I think my general suggestion would be: let's treat possibly-multiple node annotations as producing possibly-multiple signatures. |
||
| _ -> Nothing | ||
| else Nothing -- TODO(@linj) must function node be HsVar? | ||
| where | ||
| extractName = rightToMaybe | ||
|
|
||
| -- TODO(@linj) share code with getNodeName | ||
| getNodeType :: HieKind a -> RealSrcSpan -> HieAST a -> Maybe Text | ||
| getNodeType (hieKind :: HieKind a) _span hieAst = | ||
| if nodeHasAnnotation ("HsVar", "HsExpr") hieAst | ||
| then | ||
| case M.elems $ M.filter isUse $ getSourceNodeIds hieAst of | ||
| [identifierDetails] -> identType identifierDetails >>= (prettyType >>> Just) | ||
|
There was a problem hiding this comment. I suggest not printing the type here and instead returning the type itself. That would mean that when you're doing |
||
| _ -> Nothing -- TODO(@linj) will there be more than one identifierDetails? | ||
| else Nothing | ||
| where | ||
| -- modified from Development.IDE.Spans.AtPoint.atPoint | ||
| prettyType :: a -> Text | ||
| prettyType = expandType >>> printOutputable | ||
|
|
||
| expandType :: a -> SDoc | ||
| expandType t = case hieKind of | ||
| HieFresh -> ppr t | ||
| HieFromDisk hieFile -> ppr $ hieTypeToIface $ recoverFullType t (hie_types hieFile) | ||
|
|
||
| isUse :: IdentifierDetails a -> Bool | ||
| isUse = identInfo >>> S.member Use | ||
|
|
||
| -- Just 1 means the first argument | ||
| getArgumentNumber :: RealSrcSpan -> HieAST a -> Maybe Integer | ||
| getArgumentNumber span hieAst = | ||
| if nodeHasAnnotation ("HsApp", "HsExpr") hieAst | ||
| then | ||
| case nodeChildren hieAst of | ||
| [leftChild, _] -> | ||
| if span `isRealSubspanOf` nodeSpan leftChild | ||
| then Nothing | ||
| else getArgumentNumber span leftChild >>= \argumentNumber -> Just (argumentNumber + 1) | ||
| _ -> Nothing -- impossible | ||
| else | ||
| case nodeChildren hieAst of | ||
| [] -> Just 0 -- the function is found | ||
| [child] -> getArgumentNumber span child -- ignore irrelevant nodes | ||
| _ -> Nothing -- TODO(@linj) handle more cases such as `if` | ||
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Oops, something went wrong.
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
I think this is reasonable. Really
combineResponsesshould have a way to return an error. There are a bunch of methods where it really only makes sense if we have one handler.We could try to combine responses: we would combine the signatures, and so long as only one of them indicated an active signature it would be okay. But that's a bit sketchy and I doubt we'll have several anyway!