diff options
Diffstat (limited to 'compiler/hsSyn/HsDecls.hs')
| -rw-r--r-- | compiler/hsSyn/HsDecls.hs | 30 |
1 files changed, 20 insertions, 10 deletions
diff --git a/compiler/hsSyn/HsDecls.hs b/compiler/hsSyn/HsDecls.hs index c194c2e21a..e328bf43c7 100644 --- a/compiler/hsSyn/HsDecls.hs +++ b/compiler/hsSyn/HsDecls.hs @@ -679,11 +679,15 @@ countTyClDecls decls -- | Does this declaration have a complete, user-supplied kind signature? -- See Note [CUSKs: complete user-supplied kind signatures] -hsDeclHasCusk :: TyClDecl GhcRn -> Bool -hsDeclHasCusk (FamDecl { tcdFam = fam_decl }) - = famDeclHasCusk False fam_decl +hsDeclHasCusk + :: Bool -- True <=> the -XCUSKs extension is enabled + -> TyClDecl GhcRn + -> Bool +hsDeclHasCusk _cusks_enabled@False _ = False +hsDeclHasCusk cusks_enabled (FamDecl { tcdFam = fam_decl }) + = famDeclHasCusk cusks_enabled False fam_decl -- False: this is not: an associated type of a class with no cusk -hsDeclHasCusk (SynDecl { tcdTyVars = tyvars, tcdRhs = rhs }) +hsDeclHasCusk _cusks_enabled@True (SynDecl { tcdTyVars = tyvars, tcdRhs = rhs }) -- NB: Keep this synchronized with 'getInitialKind' = hsTvbAllKinded tyvars && rhs_annotated rhs where @@ -691,9 +695,9 @@ hsDeclHasCusk (SynDecl { tcdTyVars = tyvars, tcdRhs = rhs }) HsParTy _ lty -> rhs_annotated lty HsKindSig {} -> True _ -> False -hsDeclHasCusk (DataDecl { tcdDExt = DataDeclRn { tcdDataCusk = cusk }}) = cusk -hsDeclHasCusk (ClassDecl { tcdTyVars = tyvars }) = hsTvbAllKinded tyvars -hsDeclHasCusk (XTyClDecl _) = panic "hsDeclHasCusk" +hsDeclHasCusk _cusks_enabled@True (DataDecl { tcdDExt = DataDeclRn { tcdDataCusk = cusk }}) = cusk +hsDeclHasCusk _cusks_enabled@True (ClassDecl { tcdTyVars = tyvars }) = hsTvbAllKinded tyvars +hsDeclHasCusk _ (XTyClDecl _) = panic "hsDeclHasCusk" -- Pretty-printing TyClDecl -- ~~~~~~~~~~~~~~~~~~~~~~~~ @@ -787,6 +791,10 @@ declaration before checking all of the others, supporting polymorphic recursion. See https://gitlab.haskell.org/ghc/ghc/wikis/ghc-kinds/kind-inference#proposed-new-strategy and #9200 for lots of discussion of how we got here. +The detection of CUSKs is enabled by the -XCUSKs extension, switched on by default. +Under -XNoCUSKs, all declarations are treated as if they have no CUSK. +See https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0036-kind-signatures.rst + PRINCIPLE: a type declaration has a CUSK iff we could produce a separate kind signature for it, just like a type signature for a function, @@ -1080,11 +1088,13 @@ data FamilyInfo pass -- | Does this family declaration have a complete, user-supplied kind signature? -- See Note [CUSKs: complete user-supplied kind signatures] -famDeclHasCusk :: Bool -- ^ True <=> this is an associated type family, +famDeclHasCusk :: Bool -- ^ True <=> the -XCUSKs extension is enabled + -> Bool -- ^ True <=> this is an associated type family, -- and the parent class has /no/ CUSK -> FamilyDecl pass -> Bool -famDeclHasCusk assoc_with_no_cusk +famDeclHasCusk _cusks_enabled@False _ _ = False +famDeclHasCusk _cusks_enabled@True assoc_with_no_cusk (FamilyDecl { fdInfo = fam_info , fdTyVars = tyvars , fdResultSig = L _ resultSig }) @@ -1095,7 +1105,7 @@ famDeclHasCusk assoc_with_no_cusk -- Un-associated open type/data families have CUSKs -- Associated type families have CUSKs iff the parent class does -famDeclHasCusk _ (XFamilyDecl {}) = panic "famDeclHasCusk" +famDeclHasCusk _ _ (XFamilyDecl {}) = panic "famDeclHasCusk" -- | Does this family declaration have user-supplied return kind signature? hasReturnKindSignature :: FamilyResultSig a -> Bool |