diff options
Diffstat (limited to 'compiler/Language/Haskell/Syntax')
| -rw-r--r-- | compiler/Language/Haskell/Syntax/Binds.hs | 3 | ||||
| -rw-r--r-- | compiler/Language/Haskell/Syntax/Expr.hs | 24 | ||||
| -rw-r--r-- | compiler/Language/Haskell/Syntax/Pat.hs | 2 | ||||
| -rw-r--r-- | compiler/Language/Haskell/Syntax/Type.hs | 49 |
4 files changed, 49 insertions, 29 deletions
diff --git a/compiler/Language/Haskell/Syntax/Binds.hs b/compiler/Language/Haskell/Syntax/Binds.hs index 8c69f10eb8..60ca3fad1b 100644 --- a/compiler/Language/Haskell/Syntax/Binds.hs +++ b/compiler/Language/Haskell/Syntax/Binds.hs @@ -33,6 +33,7 @@ import {-# SOURCE #-} Language.Haskell.Syntax.Pat import Language.Haskell.Syntax.Extension import Language.Haskell.Syntax.Type +import GHC.Types.Name.Reader(RdrName) import GHC.Tc.Types.Evidence import GHC.Core.Type import GHC.Types.Basic @@ -931,7 +932,7 @@ when we have a different name for the local and top-level binder, making the distinction between the two names clear. -} -instance Outputable (RecordPatSynField a) where +instance Outputable (XRec a RdrName) => Outputable (RecordPatSynField a) where ppr (RecordPatSynField { recordPatSynField = v }) = ppr v diff --git a/compiler/Language/Haskell/Syntax/Expr.hs b/compiler/Language/Haskell/Syntax/Expr.hs index e7756cc804..17a0929976 100644 --- a/compiler/Language/Haskell/Syntax/Expr.hs +++ b/compiler/Language/Haskell/Syntax/Expr.hs @@ -265,6 +265,24 @@ is Less Cool because typecheck do-notation with (>>=) :: m1 a -> (a -> m2 b) -> m2 b.) -} +{- +Note [Non-overloaded record field selectors] +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +Consider + data T = MkT { x,y :: Int } + f r x = x + y r + +This parses with HsVar for x, y, r on the RHS of f. Then, if +-XOverloadedRecordFields is /off/, the renamer recognises that y in +the RHS of f is really a record selector, and changes it to a +HsRecFld. In contrast x is locally bound, shadowing the record +selector, and stay as an HsVar. + +The renamer adds the Name of the record selector into the XRecFld +extension field, The typechecker keeps HsRecFld as HsRecFld, and +transforms the record-selector Name to an Id. +-} + -- | A Haskell expression. data HsExpr p = HsVar (XVar p) @@ -287,10 +305,8 @@ data HsExpr p -- HsVar for pretty printing | HsRecFld (XRecFld p) - (AmbiguousFieldOcc p) -- ^ Variable pointing to record selector - -- The parser produces HsVars - -- The renamer renames record-field selectors to HsRecFld - -- The typechecker preserves HsRecFld + (FieldOcc p) -- ^ Variable pointing to record selector + -- See Note [Non-overloaded record field selectors] | HsOverLabel (XOverLabel p) FastString -- ^ Overloaded label (Note [Overloaded labels] in GHC.OverloadedLabels) diff --git a/compiler/Language/Haskell/Syntax/Pat.hs b/compiler/Language/Haskell/Syntax/Pat.hs index 4417026478..a7fb5d8640 100644 --- a/compiler/Language/Haskell/Syntax/Pat.hs +++ b/compiler/Language/Haskell/Syntax/Pat.hs @@ -345,7 +345,7 @@ hsRecFieldsArgs :: forall p arg. UnXRec p => HsRecFields p arg -> [arg] hsRecFieldsArgs rbinds = map (hsRecFieldArg . unXRec @p) (rec_flds rbinds) hsRecFieldSel :: HsRecField pass arg -> Located (XCFieldOcc pass) -hsRecFieldSel = fmap extFieldOcc . hsRecFieldLbl +hsRecFieldSel = fmap foExt . hsRecFieldLbl {- diff --git a/compiler/Language/Haskell/Syntax/Type.hs b/compiler/Language/Haskell/Syntax/Type.hs index f23072c04a..f7ebe42da0 100644 --- a/compiler/Language/Haskell/Syntax/Type.hs +++ b/compiler/Language/Haskell/Syntax/Type.hs @@ -6,6 +6,7 @@ {-# LANGUAGE ScopedTypeVariables #-} {-# LANGUAGE StandaloneDeriving #-} {-# LANGUAGE TypeFamilies #-} +{-# LANGUAGE TypeApplications #-} {-# LANGUAGE UndecidableInstances #-} -- Wrinkle in Note [Trees That Grow] -- in module Language.Haskell.Syntax.Extension {- @@ -1248,31 +1249,34 @@ type LFieldOcc pass = XRec pass (FieldOcc pass) -- | Field Occurrence -- --- Represents an *occurrence* of an unambiguous field. This may or may not be a +-- Represents an *occurrence* of a field. This may or may not be a -- binding occurrence (e.g. this type is used in 'ConDeclField' and --- 'RecordPatSynField' which bind their fields, but also in 'HsRecField' for --- record construction and patterns, which do not). +-- 'RecordPatSynField' which bind their fields, but also in +-- 'HsRecField' for record construction and patterns, which do not). -- --- We store both the 'RdrName' the user originally wrote, and after the renamer, --- the selector function. -data FieldOcc pass = FieldOcc { extFieldOcc :: XCFieldOcc pass - , rdrNameFieldOcc :: LocatedN RdrName - -- ^ See Note [Located RdrNames] in "GHC.Hs.Expr" - } - - | XFieldOcc - !(XXFieldOcc pass) - -deriving instance (Eq (XCFieldOcc pass), Eq (XXFieldOcc pass)) => Eq (FieldOcc pass) +-- We store both the 'RdrName' the user originally wrote, and after +-- the renamer we use the extension field to store the selector +-- function. +data FieldOcc pass + = FieldOcc { + foExt :: XCFieldOcc pass + , foLabel :: XRec pass RdrName -- See Note [Located RdrNames] in Language.Haskell.Syntax.Expr + } + | XFieldOcc !(XXFieldOcc pass) +deriving instance ( + Eq (XRec pass RdrName) + , Eq (XCFieldOcc pass) + , Eq (XXFieldOcc pass) + ) => Eq (FieldOcc pass) -instance Outputable (FieldOcc pass) where - ppr = ppr . rdrNameFieldOcc +instance Outputable (XRec pass RdrName) => Outputable (FieldOcc pass) where + ppr = ppr . foLabel -instance OutputableBndr (FieldOcc pass) where - pprInfixOcc = pprInfixOcc . unLoc . rdrNameFieldOcc - pprPrefixOcc = pprPrefixOcc . unLoc . rdrNameFieldOcc +instance (UnXRec pass, OutputableBndr (XRec pass RdrName)) => OutputableBndr (FieldOcc pass) where + pprInfixOcc = pprInfixOcc . unXRec @pass . foLabel + pprPrefixOcc = pprPrefixOcc . unXRec @pass . foLabel -instance OutputableBndr (GenLocated SrcSpan (FieldOcc pass)) where +instance (UnXRec pass, OutputableBndr (XRec pass RdrName)) => OutputableBndr (GenLocated SrcSpan (FieldOcc pass)) where pprInfixOcc = pprInfixOcc . unLoc pprPrefixOcc = pprPrefixOcc . unLoc @@ -1285,9 +1289,8 @@ instance OutputableBndr (GenLocated SrcSpan (FieldOcc pass)) where -- (for unambiguous occurrences) or the typechecker (for ambiguous -- occurrences). -- --- See Note [HsRecField and HsRecUpdField] in "GHC.Hs.Pat" and --- Note [Disambiguating record fields] in "GHC.Tc.Gen.Head". --- See Note [Located RdrNames] in "GHC.Hs.Expr" +-- See Note [HsRecField and HsRecUpdField] in "GHC.Hs.Pat". +-- See Note [Located RdrNames] in "GHC.Hs.Expr". data AmbiguousFieldOcc pass = Unambiguous (XUnambiguous pass) (LocatedN RdrName) | Ambiguous (XAmbiguous pass) (LocatedN RdrName) |