diff options
Diffstat (limited to 'compiler/GHC/Tc/Utils/TcMType.hs')
| -rw-r--r-- | compiler/GHC/Tc/Utils/TcMType.hs | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/compiler/GHC/Tc/Utils/TcMType.hs b/compiler/GHC/Tc/Utils/TcMType.hs index ccebfd6716..66a05aa30e 100644 --- a/compiler/GHC/Tc/Utils/TcMType.hs +++ b/compiler/GHC/Tc/Utils/TcMType.hs @@ -364,7 +364,7 @@ unpackCoercionHole_maybe :: CoercionHole -> TcM (Maybe Coercion) unpackCoercionHole_maybe (CoercionHole { ch_ref = ref }) = readTcRef ref -- | Check that a coercion is appropriate for filling a hole. (The hole --- itself is needed only for printing. +-- itself is needed only for printing.) -- Always returns the checked coercion, but this return value is necessary -- so that the input coercion is forced only when the output is forced. checkCoercionHole :: CoVar -> Coercion -> TcM Coercion @@ -880,7 +880,7 @@ cloneAnonMetaTyVar info tv kind ; traceTc "cloneAnonMetaTyVar" (ppr tyvar <+> dcolon <+> ppr (tyVarKind tyvar)) ; return tyvar } --- Make a new CycleBreakerTv. See Note [Type variable cycles in Givens] +-- Make a new CycleBreakerTv. See Note [Type variable cycles] -- in GHC.Tc.Solver.Canonical. newCycleBreakerTyVar :: TcKind -> TcM TcTyVar newCycleBreakerTyVar kind @@ -2324,7 +2324,7 @@ zonkHole hole@(Hole { hole_ty = ty }) ~~~~~~~~~~~~~~~~~~~~~~~~~~ zonkCt tries to maintain the canonical form of a Ct. For example, - a CDictCan should stay a CDictCan; - - a CIrredCan should stay a CIrredCan with its cc_status flag intact + - a CIrredCan should stay a CIrredCan with its cc_reason flag intact Why?, for example: - For CDictCan, the @GHC.Tc.Solver.expandSuperClasses@ step, which runs after the @@ -2357,7 +2357,7 @@ zonkCt ct@(CDictCan { cc_ev = ev, cc_tyargs = args }) zonkCt (CEqCan { cc_ev = ev }) = mkNonCanonical <$> zonkCtEvidence ev -zonkCt ct@(CIrredCan { cc_ev = ev }) -- Preserve the cc_status flag +zonkCt ct@(CIrredCan { cc_ev = ev }) -- Preserve the cc_reason flag = do { ev' <- zonkCtEvidence ev ; return (ct { cc_ev = ev' }) } |