diff options
| -rw-r--r-- | compiler/typecheck/TcType.hs | 17 |
1 files changed, 6 insertions, 11 deletions
diff --git a/compiler/typecheck/TcType.hs b/compiler/typecheck/TcType.hs index f814a5ff9a..5013f470da 100644 --- a/compiler/typecheck/TcType.hs +++ b/compiler/typecheck/TcType.hs @@ -646,23 +646,18 @@ Note [TcLevel assignment] ~~~~~~~~~~~~~~~~~~~~~~~~~ We arrange the TcLevels like this + 0 Level for flatten meta-vars 1 Top level - 2 Flatten-meta-vars of level 3 - 3 First-level implication constraints - 4 Flatten-meta-vars of level 5 - 5 Second-level implication constraints + 2 First-level implication constraints + 3 Second-level implication constraints ...etc... -The even-numbered levels are for the flatten-meta-variables assigned -at the next level in. Eg for a second-level implication constraint -(level 5), the flatten meta-vars are level 4, which makes them untouchable. -The flatten meta-vars could equally well all have level 0, or just NotALevel -since they do not live across implications. +The flatten meta-vars are all at level 0, just to make them untouchable. -} fmvTcLevel :: TcLevel -> TcLevel -- See Note [TcLevel assignment] -fmvTcLevel (TcLevel n) = TcLevel (n-1) +fmvTcLevel _ = TcLevel 0 topTcLevel :: TcLevel -- See Note [TcLevel assignment] @@ -674,7 +669,7 @@ isTopTcLevel _ = False pushTcLevel :: TcLevel -> TcLevel -- See Note [TcLevel assignment] -pushTcLevel (TcLevel us) = TcLevel (us + 2) +pushTcLevel (TcLevel us) = TcLevel (us + 1) strictlyDeeperThan :: TcLevel -> TcLevel -> Bool strictlyDeeperThan (TcLevel tv_tclvl) (TcLevel ctxt_tclvl) |