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| author | Simon Peyton Jones <simonpj@microsoft.com> | 2015-04-14 09:21:27 +0100 |
|---|---|---|
| committer | Simon Peyton Jones <simonpj@microsoft.com> | 2015-04-14 09:22:04 +0100 |
| commit | a2ce3afaeb5c32556760b9b5185778a4062ba998 (patch) | |
| tree | 818eb0d00678af46435b0a68a4bd4bf9233a2310 | |
| parent | 25f2d68849288a57ae4c6ce492f9e0bdd6df83bb (diff) | |
| download | haskell-a2ce3afaeb5c32556760b9b5185778a4062ba998.tar.gz | |
Comments and white space only
| -rw-r--r-- | compiler/typecheck/TcFlatten.hs | 4 | ||||
| -rw-r--r-- | compiler/typecheck/TcRules.hs | 10 |
2 files changed, 9 insertions, 5 deletions
diff --git a/compiler/typecheck/TcFlatten.hs b/compiler/typecheck/TcFlatten.hs index cd7c3d6c81..89431f80b7 100644 --- a/compiler/typecheck/TcFlatten.hs +++ b/compiler/typecheck/TcFlatten.hs @@ -553,7 +553,7 @@ instance Applicative FlatM where liftTcS :: TcS a -> FlatM a liftTcS thing_inside - = FlatM $ const thing_inside + = FlatM $ const thing_inside emitFlatWork :: Ct -> FlatM () -- See Note [The flattening work list] @@ -622,7 +622,7 @@ setEqRel new_eq_rel thing_inside if new_eq_rel == fe_eq_rel env then runFlatM thing_inside env else runFlatM thing_inside (env { fe_eq_rel = new_eq_rel }) - + -- | Change the 'FlattenMode' in a 'FlattenEnv'. setMode :: FlattenMode -> FlatM a -> FlatM a setMode new_mode thing_inside diff --git a/compiler/typecheck/TcRules.hs b/compiler/typecheck/TcRules.hs index 168411830e..084e5dea5a 100644 --- a/compiler/typecheck/TcRules.hs +++ b/compiler/typecheck/TcRules.hs @@ -227,11 +227,15 @@ revert to SimplCheck when going under an implication. ------------------------ So the plan is this ----------------------- +* Step 0: typecheck the LHS and RHS to get constraints from each + * Step 1: Simplify the LHS and RHS constraints all together in one bag We do this to discover all unification equalities -* Step 2: Zonk the ORIGINAL lhs constraints, and partition them into - the ones we will quantify over, and the others +* Step 2: Zonk the ORIGINAL (unsimplified) lhs constraints, to take + advantage of those unifications, and partition them into the + ones we will quantify over, and the others + See Note [RULE quantification over equalities] * Step 3: Decide on the type variables to quantify over @@ -251,7 +255,7 @@ From the RULE we get lhs-constraints: T Int ~ alpha rhs-constraints: Bool ~ alpha where 'alpha' is the type that connects the two. If we glom them -all together, and solve the RHS constraint first, we might solve +all together, and solve the RHS constraint first, we might solve with alpha := Bool. But then we'd end up with a RULE like RULE: f 3 |> (co :: T Int ~ Booo) = True |