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| author | Manuel M T Chakravarty <chak@cse.unsw.edu.au> | 2006-12-29 20:17:51 +0000 |
|---|---|---|
| committer | Manuel M T Chakravarty <chak@cse.unsw.edu.au> | 2006-12-29 20:17:51 +0000 |
| commit | c8732b3c99e93c36ad28e23d2b901b794e89542a (patch) | |
| tree | 2a7aa06227c0b170d0551f304d048c1c4aa0d29c /compiler/parser/Parser.y.pp | |
| parent | 0aa1d46a1e5c19553c410dc6ff65b29594a2499f (diff) | |
| download | haskell-c8732b3c99e93c36ad28e23d2b901b794e89542a.tar.gz | |
EqPred pretty prints as ~ and equalities without brackets
Diffstat (limited to 'compiler/parser/Parser.y.pp')
| -rw-r--r-- | compiler/parser/Parser.y.pp | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/compiler/parser/Parser.y.pp b/compiler/parser/Parser.y.pp index 009eddca62..f72c8b9d83 100644 --- a/compiler/parser/Parser.y.pp +++ b/compiler/parser/Parser.y.pp @@ -971,8 +971,13 @@ ctype :: { LHsType RdrName } -- errors in ctype. The basic problem is that -- (Eq a, Ord a) -- looks so much like a tuple type. We can't tell until we find the => +-- +-- We have the t1 ~ t2 form here and in gentype, to permit an individual +-- equational constraint without parenthesis. context :: { LHsContext RdrName } - : btype {% checkContext $1 } + : btype '~' btype {% checkContext + (LL $ HsPredTy (HsEqualP $1 $3)) } + | btype {% checkContext $1 } type :: { LHsType RdrName } : ipvar '::' gentype { LL (HsPredTy (HsIParam (unLoc $1) $3)) } @@ -983,7 +988,7 @@ gentype :: { LHsType RdrName } | btype qtyconop gentype { LL $ HsOpTy $1 $2 $3 } | btype tyvarop gentype { LL $ HsOpTy $1 $2 $3 } | btype '->' ctype { LL $ HsFunTy $1 $3 } - | btype '~' gentype { LL $ HsPredTy (HsEqualP $1 $3) } + | btype '~' btype { LL $ HsPredTy (HsEqualP $1 $3) } btype :: { LHsType RdrName } : btype atype { LL $ HsAppTy $1 $2 } |