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| author | Richard Eisenberg <rae@richarde.dev> | 2019-10-08 14:10:46 +0100 |
|---|---|---|
| committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2019-10-17 01:03:51 -0400 |
| commit | 4efdda9057366db3ecf6beb3b889f830c0d8d641 (patch) | |
| tree | 2eb06cee82aa5fcfe5b49cc14fb287e7290fe57d | |
| parent | b15a7fb8aa022bfdf3286d65227061c19a4acf28 (diff) | |
| download | haskell-4efdda9057366db3ecf6beb3b889f830c0d8d641.tar.gz | |
Tiny fixes to comments around flattening.
| -rw-r--r-- | compiler/typecheck/TcFlatten.hs | 4 | ||||
| -rw-r--r-- | compiler/typecheck/TcHsType.hs | 2 |
2 files changed, 3 insertions, 3 deletions
diff --git a/compiler/typecheck/TcFlatten.hs b/compiler/typecheck/TcFlatten.hs index 8f271ac444..69ced0b00e 100644 --- a/compiler/typecheck/TcFlatten.hs +++ b/compiler/typecheck/TcFlatten.hs @@ -815,7 +815,7 @@ Because flattening zonks and the returned coercion ("co" above) is also zonked, it's possible that (co :: xi ~ ty) isn't quite true. So, instead, we can rely on this fact: - (F1) tcTypeKind(xi) succeeds and returns a fully zonked kind + (F0) co :: xi ~ zonk(ty) Note that the left-hand type of co is *always* precisely xi. The right-hand type may or may not be ty, however: if ty has unzonked filled-in metavariables, @@ -1535,7 +1535,7 @@ flattenTyVar tv ; return (ty2, co2 `mkTransCo` co1) } FTRNotFollowed -- Done, but make sure the kind is zonked - -- Note [Flattening] invariant (F1) + -- Note [Flattening] invariant (F0) and (F1) -> do { tv' <- liftTcS $ updateTyVarKindM zonkTcType tv ; role <- getRole ; let ty' = mkTyVarTy tv' diff --git a/compiler/typecheck/TcHsType.hs b/compiler/typecheck/TcHsType.hs index c2776c7b1b..82cc6e2002 100644 --- a/compiler/typecheck/TcHsType.hs +++ b/compiler/typecheck/TcHsType.hs @@ -1293,7 +1293,7 @@ The calls to mkAppTyM is the other place we are very careful. Note [mkAppTyM] ~~~~~~~~~~~~~~~ -mkAppTyM is trying to guaranteed the Purely Kinded Type Invariant +mkAppTyM is trying to guarantee the Purely Kinded Type Invariant (PKTI) for its result type (fun arg). There are two ways it can go wrong: * Nasty case 1: forall types (polykinds/T14174a) |