diff options
Diffstat (limited to 'compiler/GHC/Tc/Solver/Monad.hs')
| -rw-r--r-- | compiler/GHC/Tc/Solver/Monad.hs | 17 |
1 files changed, 8 insertions, 9 deletions
diff --git a/compiler/GHC/Tc/Solver/Monad.hs b/compiler/GHC/Tc/Solver/Monad.hs index 99c35f826d..6621f54317 100644 --- a/compiler/GHC/Tc/Solver/Monad.hs +++ b/compiler/GHC/Tc/Solver/Monad.hs @@ -89,7 +89,7 @@ module GHC.Tc.Solver.Monad ( instDFunType, -- Instantiation -- MetaTyVars - newFlexiTcSTy, instFlexi, instFlexiX, + newFlexiTcSTy, instFlexiX, cloneMetaTyVar, tcInstSkolTyVarsX, @@ -1614,22 +1614,21 @@ newFlexiTcSTy knd = wrapTcS (TcM.newFlexiTyVarTy knd) cloneMetaTyVar :: TcTyVar -> TcS TcTyVar cloneMetaTyVar tv = wrapTcS (TcM.cloneMetaTyVar tv) -instFlexi :: [TKVar] -> TcS TCvSubst -instFlexi = instFlexiX emptyTCvSubst - instFlexiX :: TCvSubst -> [TKVar] -> TcS TCvSubst instFlexiX subst tvs = wrapTcS (foldlM instFlexiHelper subst tvs) instFlexiHelper :: TCvSubst -> TKVar -> TcM TCvSubst +-- Makes fresh tyvar, extends the substitution, and the in-scope set instFlexiHelper subst tv = do { uniq <- TcM.newUnique ; details <- TcM.newMetaDetails TauTv - ; let name = setNameUnique (tyVarName tv) uniq - kind = substTyUnchecked subst (tyVarKind tv) - ty' = mkTyVarTy (mkTcTyVar name kind details) - ; TcM.traceTc "instFlexi" (ppr ty') - ; return (extendTvSubst subst tv ty') } + ; let name = setNameUnique (tyVarName tv) uniq + kind = substTyUnchecked subst (tyVarKind tv) + tv' = mkTcTyVar name kind details + subst' = extendTvSubstWithClone subst tv tv' + ; TcM.traceTc "instFlexi" (ppr tv') + ; return (extendTvSubst subst' tv (mkTyVarTy tv')) } matchGlobalInst :: DynFlags -> Bool -- True <=> caller is the short-cut solver |