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| author | Simon Peyton Jones <simonpj@microsoft.com> | 2020-07-14 16:41:03 +0100 |
|---|---|---|
| committer | Simon Peyton Jones <simonpj@microsoft.com> | 2020-07-15 09:42:46 +0100 |
| commit | 52bdb5bb05bd6c10b84c69e98587f4e1b65110e1 (patch) | |
| tree | 7d08e45fd3336ae0a1bee22f9404d1b826c036fb /compiler/GHC/Tc/Utils/Env.hs | |
| parent | 7e741433dc7c8e52121c85ad9e8e520da4d54bd8 (diff) | |
| download | haskell-wip/T18412.tar.gz | |
Improve typechecking of NPlusK patternswip/T18412
This patch (due to Richard Eisenberg) improves
documentation of the wrapper returned by tcSubMult
(see Note [Wrapper returned from tcSubMult] in
GHC.Tc.Utils.Unify).
And, more substantially, it cleans up the multiplicity
handling in the typechecking of NPlusKPat
Diffstat (limited to 'compiler/GHC/Tc/Utils/Env.hs')
| -rw-r--r-- | compiler/GHC/Tc/Utils/Env.hs | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/compiler/GHC/Tc/Utils/Env.hs b/compiler/GHC/Tc/Utils/Env.hs index e8640a08dc..76ebb79e1e 100644 --- a/compiler/GHC/Tc/Utils/Env.hs +++ b/compiler/GHC/Tc/Utils/Env.hs @@ -628,7 +628,8 @@ tcExtendLocalTypeEnv lcl_env@(TcLclEnv { tcl_env = lcl_type_env }) tc_ty_things -- | @tcCheckUsage name mult thing_inside@ runs @thing_inside@, checks that the -- usage of @name@ is a submultiplicity of @mult@, and removes @name@ from the --- usage environment. See also Note [tcSubMult's wrapper] in TcUnify. +-- usage environment. See also Note [Wrapper returned from tcSubMult] in +-- GHC.Tc.Utils.Unify, which applies to the wrapper returned from this function. tcCheckUsage :: Name -> Mult -> TcM a -> TcM (a, HsWrapper) tcCheckUsage name id_mult thing_inside = do { (local_usage, result) <- tcCollectingUsage thing_inside |