diff options
Diffstat (limited to 'haddock-api/src/Haddock/GhcUtils.hs')
| -rw-r--r-- | haddock-api/src/Haddock/GhcUtils.hs | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/haddock-api/src/Haddock/GhcUtils.hs b/haddock-api/src/Haddock/GhcUtils.hs index b2c34bb4..e7d80969 100644 --- a/haddock-api/src/Haddock/GhcUtils.hs +++ b/haddock-api/src/Haddock/GhcUtils.hs @@ -31,6 +31,8 @@ import GHC import Class import DynFlags +import HsTypes (HsType(..)) + moduleString :: Module -> String moduleString = moduleNameString . moduleName @@ -226,6 +228,100 @@ getGADTConTypeG (ConDeclH98 {}) = panic "getGADTConTypeG" -- Should only be called on ConDeclGADT getGADTConTypeG (XConDecl {}) = panic "getGADTConTypeG" + +------------------------------------------------------------------------------- +-- * Parenthesization +------------------------------------------------------------------------------- + +-- | Precedence level (inside the 'HsType' AST). +data Precedence + = PREC_TOP -- ^ precedence of 'type' production in GHC's parser + + | PREC_CTX -- ^ Used for single contexts, eg. ctx => type + -- (as opposed to (ctx1, ctx2) => type) + + | PREC_FUN -- ^ precedence of 'btype' production in GHC's parser + -- (used for LH arg of (->)) + + | PREC_OP -- ^ arg of any infix operator + -- (we don't keep have fixity info) + + | PREC_CON -- ^ arg of type application: always parenthesize unless atomic + deriving (Eq, Ord) + +-- | Add in extra 'HsParTy' where needed to ensure that what would be printed +-- out using 'ppr' has enough parentheses to be re-parsed properly. +-- +-- We cannot add parens that may be required by fixities because we do not have +-- any fixity information to work with in the first place :(. +reparenTypePrec :: (XParTy a ~ NoExt) => Precedence -> HsType a -> HsType a +reparenTypePrec = go + where + + -- Shorter name for 'reparenType' + go :: (XParTy a ~ NoExt) => Precedence -> HsType a -> HsType a + go _ (HsBangTy x b ty) = HsBangTy x b (reparenLType ty) + go _ (HsTupleTy x con tys) = HsTupleTy x con (map reparenLType tys) + go _ (HsSumTy x tys) = HsSumTy x (map reparenLType tys) + go _ (HsKindSig x ty kind) = HsKindSig x (reparenLType ty) (reparenLType kind) + go _ (HsListTy x ty) = HsListTy x (reparenLType ty) + go _ (HsRecTy x flds) = HsRecTy x (map (fmap reparenConDeclField) flds) + go p (HsDocTy x ty d) = HsDocTy x (goL p ty) d + go _ (HsExplicitListTy x p tys) = HsExplicitListTy x p (map reparenLType tys) + go _ (HsExplicitTupleTy x tys) = HsExplicitTupleTy x (map reparenLType tys) + go p (HsIParamTy x n ty) + = paren p PREC_CTX $ HsIParamTy x n (reparenLType ty) + go p (HsForAllTy x tvs ty) + = paren p PREC_CTX $ HsForAllTy x (map (fmap reparenTyVar) tvs) (reparenLType ty) + go p (HsQualTy x ctxt ty) + = paren p PREC_FUN $ HsQualTy x (fmap (map reparenLType) ctxt) (reparenLType ty) + go p (HsFunTy x ty1 ty2) + = paren p PREC_FUN $ HsFunTy x (goL PREC_FUN ty1) (goL PREC_TOP ty2) + go p (HsAppTy x fun_ty arg_ty) + = paren p PREC_CON $ HsAppTy x (goL PREC_FUN fun_ty) (goL PREC_CON arg_ty) + go p (HsOpTy x ty1 op ty2) + = paren p PREC_FUN $ HsOpTy x (goL PREC_OP ty1) op (goL PREC_OP ty2) + go p (HsParTy _ t) = unLoc $ goL p t -- pretend the paren doesn't exist - it will be added back if needed + go _ t@HsTyVar{} = t + go _ t@HsStarTy{} = t + go _ t@HsSpliceTy{} = t + go _ t@HsTyLit{} = t + go _ t@HsWildCardTy{} = t + go _ t@XHsType{} = t + + -- Located variant of 'go' + goL :: (XParTy a ~ NoExt) => Precedence -> LHsType a -> LHsType a + goL ctxt_prec = fmap (go ctxt_prec) + + -- Optionally wrap a type in parens + paren :: (XParTy a ~ NoExt) + => Precedence -- Precedence of context + -> Precedence -- Precedence of top-level operator + -> HsType a -> HsType a -- Wrap in parens if (ctxt >= op) + paren ctxt_prec op_prec | ctxt_prec >= op_prec = HsParTy NoExt . noLoc + | otherwise = id + + +-- | Add parenthesis around the types in a 'HsType' (see 'reparenTypePrec') +reparenType :: (XParTy a ~ NoExt) => HsType a -> HsType a +reparenType = reparenTypePrec PREC_TOP + +-- | Add parenthesis around the types in a 'LHsType' (see 'reparenTypePrec') +reparenLType :: (XParTy a ~ NoExt) => LHsType a -> LHsType a +reparenLType = fmap reparenType + +-- | Add parenthesis around the types in a 'HsTyVarBndr' (see 'reparenTypePrec') +reparenTyVar :: (XParTy a ~ NoExt) => HsTyVarBndr a -> HsTyVarBndr a +reparenTyVar (UserTyVar x n) = UserTyVar x n +reparenTyVar (KindedTyVar x n kind) = KindedTyVar x n (reparenLType kind) +reparenTyVar v@XTyVarBndr{} = v + +-- | Add parenthesis around the types in a 'ConDeclField' (see 'reparenTypePrec') +reparenConDeclField :: (XParTy a ~ NoExt) => ConDeclField a -> ConDeclField a +reparenConDeclField (ConDeclField x n t d) = ConDeclField x n (reparenLType t) d +reparenConDeclField c@XConDeclField{} = c + + ------------------------------------------------------------------------------- -- * Located ------------------------------------------------------------------------------- |