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| author | Adam Sandberg Eriksson <adam@sandbergericsson.se> | 2019-11-01 22:54:04 +0000 |
|---|---|---|
| committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2020-02-08 10:15:38 -0500 |
| commit | 588acb99bc3cb377ceb76447dd60656b4a11de5a (patch) | |
| tree | 598a83c392cca6ed977046685469038d661f831c /compiler/GHC | |
| parent | 7c1228511f2dd4d262c04edb8539174a7de810b2 (diff) | |
| download | haskell-588acb99bc3cb377ceb76447dd60656b4a11de5a.tar.gz | |
slightly better named cost-centres for simple pattern bindings #17006
```
main = do
print $ g [1..100] a
where g xs x = map (`mod` x) xs
a :: Int = 324
```
The above program previously attributed the cost of computing 324 to a cost
centre named `(...)`, with this change the cost is attributed to `a` instead.
This change only affects simple pattern bindings (decorated variables: type
signatures, parens, ~ annotations and ! annotations).
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 |