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Diffstat (limited to 'compiler/GHC/Hs/Decls.hs')
| -rw-r--r-- | compiler/GHC/Hs/Decls.hs | 54 |
1 files changed, 53 insertions, 1 deletions
diff --git a/compiler/GHC/Hs/Decls.hs b/compiler/GHC/Hs/Decls.hs index c4d457d808..9759225109 100644 --- a/compiler/GHC/Hs/Decls.hs +++ b/compiler/GHC/Hs/Decls.hs @@ -92,6 +92,7 @@ module GHC.Hs.Decls ( HsGroup(..), emptyRdrGroup, emptyRnGroup, appendGroups, hsGroupInstDecls, hsGroupTopLevelFixitySigs, + partitionBindsAndSigs, ) where -- friends: @@ -219,6 +220,38 @@ Template Haskell `Dec`. If there are any duplicate signatures between the two fields, this will result in an error (#17608). -} +-- | Partition a list of HsDecls into function/pattern bindings, signatures, +-- type family declarations, type family instances, and documentation comments. +-- +-- Panics when given a declaration that cannot be put into any of the output +-- groups. +-- +-- The primary use of this function is to implement +-- 'GHC.Parser.PostProcess.cvBindsAndSigs'. +partitionBindsAndSigs + :: [LHsDecl GhcPs] + -> (LHsBinds GhcPs, [LSig GhcPs], [LFamilyDecl GhcPs], + [LTyFamInstDecl GhcPs], [LDataFamInstDecl GhcPs], [LDocDecl]) +partitionBindsAndSigs = go + where + go [] = (emptyBag, [], [], [], [], []) + go ((L l decl) : ds) = + let (bs, ss, ts, tfis, dfis, docs) = go ds in + case decl of + ValD _ b + -> (L l b `consBag` bs, ss, ts, tfis, dfis, docs) + SigD _ s + -> (bs, L l s : ss, ts, tfis, dfis, docs) + TyClD _ (FamDecl _ t) + -> (bs, ss, L l t : ts, tfis, dfis, docs) + InstD _ (TyFamInstD { tfid_inst = tfi }) + -> (bs, ss, ts, L l tfi : tfis, dfis, docs) + InstD _ (DataFamInstD { dfid_inst = dfi }) + -> (bs, ss, ts, tfis, L l dfi : dfis, docs) + DocD _ d + -> (bs, ss, ts, tfis, dfis, L l d : docs) + _ -> pprPanic "partitionBindsAndSigs" (ppr decl) + -- | Haskell Group -- -- A 'HsDecl' is categorised into a 'HsGroup' before being @@ -643,10 +676,29 @@ type instance XDataDecl GhcPs = NoExtField type instance XDataDecl GhcRn = DataDeclRn type instance XDataDecl GhcTc = DataDeclRn -type instance XClassDecl GhcPs = NoExtField +type instance XClassDecl GhcPs = LayoutInfo -- See Note [Class LayoutInfo] type instance XClassDecl GhcRn = NameSet -- FVs type instance XClassDecl GhcTc = NameSet -- FVs +{- Note [Class LayoutInfo] +~~~~~~~~~~~~~~~~~~~~~~~~~~ +The LayoutInfo is used to associate Haddock comments with parts of the declaration. +Compare the following examples: + + class C a where + f :: a -> Int + -- ^ comment on f + + class C a where + f :: a -> Int + -- ^ comment on C + +Notice how "comment on f" and "comment on C" differ only by indentation level. +Thus we have to record the indentation level of the class declarations. + +See also Note [Adding Haddock comments to the syntax tree] in GHC.Parser.PostProcess.Haddock +-} + type instance XXTyClDecl (GhcPass _) = NoExtCon -- Simple classifiers for TyClDecl |