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| author | Simon Peyton Jones <simonpj@microsoft.com> | 2016-06-23 08:47:31 +0100 |
|---|---|---|
| committer | Simon Peyton Jones <simonpj@microsoft.com> | 2016-06-23 09:22:53 +0100 |
| commit | 3e0af469c97d34bea92032d54d155afc65bd4b20 (patch) | |
| tree | 63548506546b50bf1af78d82ba92340d77d42510 /compiler/typecheck/FamInst.hs | |
| parent | 210a2e122ce3b7c56c780e4541b9f222abe7d2f7 (diff) | |
| download | haskell-3e0af469c97d34bea92032d54d155afc65bd4b20.tar.gz | |
Give lookupGRE_Name a better API
lookupGRE_Name should return either zero or one GREs, never
several. This is a consequence of INVARIANT 1 on GlobalRdrEnv.
So it's better if it returns a Maybe; the panic on multiple results
is put in one place, instead of being scattered or ignored.
Just refactoring, no change in behaviour
Diffstat (limited to 'compiler/typecheck/FamInst.hs')
| -rw-r--r-- | compiler/typecheck/FamInst.hs | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/compiler/typecheck/FamInst.hs b/compiler/typecheck/FamInst.hs index 39cd1a5c84..434f1f3e60 100644 --- a/compiler/typecheck/FamInst.hs +++ b/compiler/typecheck/FamInst.hs @@ -322,7 +322,7 @@ tcTopNormaliseNewTypeTF_maybe faminsts rdr_env ty (not (isAbstractTyCon tc) && all in_scope data_con_names) where data_con_names = map dataConName (tyConDataCons tc) - in_scope dc = not $ null $ lookupGRE_Name rdr_env dc + in_scope dc = isJust (lookupGRE_Name rdr_env dc) {- ************************************************************************ |