diff options
Diffstat (limited to 'compiler/typecheck/TcRnTypes.hs')
| -rw-r--r-- | compiler/typecheck/TcRnTypes.hs | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/compiler/typecheck/TcRnTypes.hs b/compiler/typecheck/TcRnTypes.hs index 9cf338b9d0..bfedaf2ccc 100644 --- a/compiler/typecheck/TcRnTypes.hs +++ b/compiler/typecheck/TcRnTypes.hs @@ -2021,7 +2021,7 @@ dropDerivedCt ct When we discard Derived constraints, in dropDerivedSimples, we must set the cc_pend_sc flag to True, so that if we re-process this CDictCan we will re-generate its derived superclasses. Otherwise -we might miss some fundeps. Trac #13662 showed this up. +we might miss some fundeps. #13662 showed this up. See Note [The superclass story] in TcCanonical. -} @@ -2108,15 +2108,15 @@ But (tiresomely) we do keep *some* Derived constraints: Others not-definitely-insoluble ones like [D] a ~ Int do not reflect unreachable code; indeed if fundeps generated proofs, it'd - be a useful equality. See Trac #14763. So we discard them. + be a useful equality. See #14763. So we discard them. - Given/Wanted interacGiven or Wanted interacting with an instance declaration (FunDepOrigin2) - - Given/Wanted interactions (FunDepOrigin1); see Trac #9612 + - Given/Wanted interactions (FunDepOrigin1); see #9612 - But for Wanted/Wanted interactions we do /not/ want to report an - error (Trac #13506). Consider [W] C Int Int, [W] C Int Bool, with + error (#13506). Consider [W] C Int Int, [W] C Int Bool, with a fundep on class C. We don't want to report an insoluble Int~Bool; c.f. "wanteds do not rewrite wanteds". @@ -2302,7 +2302,7 @@ Note that * Superclasses help only for Wanted constraints. Derived constraints are not really "unsolved" and we certainly don't want them to trigger superclass expansion. This was a good part of the loop - in Trac #11523 + in #11523 * Even for Wanted constraints, we say "no" for implicit parameters. we have [W] ?x::ty, expanding superclasses won't help: @@ -2315,7 +2315,7 @@ Note that is low because the unsolved set is usually empty anyway (errors aside), and the first non-imlicit-parameter will terminate the search. - The special case is worth it (Trac #11480, comment:2) because it + The special case is worth it (#11480, comment:2) because it applies to CallStack constraints, which aren't type errors. If we have f :: (C a) => blah f x = ...undefined... @@ -2492,7 +2492,7 @@ ppr_bag doc bag {- Note [Given insolubles] ~~~~~~~~~~~~~~~~~~~~~~~~~~ -Consider (Trac #14325, comment:) +Consider (#14325, comment:) class (a~b) => C a b foo :: C a c => a -> c @@ -2516,7 +2516,7 @@ The same applies to Derived constraints that /arise from/ Givens. E.g. f :: (C Int [a]) => blah where a fundep means we get [D] Int ~ [a] -By the same reasoning we must not suppress other errors (Trac #15767) +By the same reasoning we must not suppress other errors (#15767) Bottom line: insolubleWC (called in TcSimplify.setImplicationStatus) should ignore givens even if they are insoluble. @@ -3015,7 +3015,7 @@ a representational equality to rewrite a nominal one. Note [Wanteds do not rewrite Wanteds] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ We don't allow Wanteds to rewrite Wanteds, because that can give rise -to very confusing type error messages. A good example is Trac #8450. +to very confusing type error messages. A good example is #8450. Here's another f :: a -> Bool f x = ( [x,'c'], [x,True] ) `seq` True |