diff options
Diffstat (limited to 'compiler/GHC')
| -rw-r--r-- | compiler/GHC/Hs/Pat.hs | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/compiler/GHC/Hs/Pat.hs b/compiler/GHC/Hs/Pat.hs index 945c2c195f..9812fe2c44 100644 --- a/compiler/GHC/Hs/Pat.hs +++ b/compiler/GHC/Hs/Pat.hs @@ -31,6 +31,7 @@ module GHC.Hs.Pat ( mkPrefixConPat, mkCharLitPat, mkNilPat, + isSimplePat, looksLazyPatBind, isBangedLPat, patNeedsParens, parenthesizePat, @@ -274,6 +275,7 @@ data Pat p | XPat (XXPat p) + -- --------------------------------------------------------------------- data ListPatTc @@ -730,6 +732,23 @@ isIrrefutableHsPat go (XPat {}) = False +-- | Is the pattern any of combination of: +-- +-- - (pat) +-- - pat :: Type +-- - ~pat +-- - !pat +-- - x (variable) +isSimplePat :: LPat (GhcPass x) -> Maybe (IdP (GhcPass x)) +isSimplePat p = case unLoc p of + ParPat _ x -> isSimplePat x + SigPat _ x _ -> isSimplePat x + LazyPat _ x -> isSimplePat x + BangPat _ x -> isSimplePat x + VarPat _ x -> Just (unLoc x) + _ -> Nothing + + {- Note [Unboxed sum patterns aren't irrefutable] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Unlike unboxed tuples, unboxed sums are *not* irrefutable when used as |