diff options
Diffstat (limited to 'compiler/specialise/Rules.hs')
| -rw-r--r-- | compiler/specialise/Rules.hs | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/compiler/specialise/Rules.hs b/compiler/specialise/Rules.hs index ad6a0757cb..df6196a655 100644 --- a/compiler/specialise/Rules.hs +++ b/compiler/specialise/Rules.hs @@ -440,7 +440,7 @@ isMoreSpecific :: CoreRule -> CoreRule -> Bool -- anything else, because we want user-define rules to "win" -- In particular, class ops have a built-in rule, but we -- any user-specific rules to win --- eg (Trac #4397) +-- eg (#4397) -- truncate :: (RealFrac a, Integral b) => a -> b -- {-# RULES "truncate/Double->Int" truncate = double2Int #-} -- double2Int :: Double -> Int @@ -619,7 +619,7 @@ It can be the case that the binder in a rule is not actually bound on the LHS: * Type variables. Type synonyms with phantom args can give rise to - unbound template type variables. Consider this (Trac #10689, + unbound template type variables. Consider this (#10689, simplCore/should_compile/T10689): type Foo a b = b @@ -653,7 +653,7 @@ bound on the LHS: fires we can substitute <t> for c. This actually happened (in a RULE for a local function) - in Trac #13410, and also in test T10602. + in #13410, and also in test T10602. Note [Cloning the template binders] @@ -674,11 +674,11 @@ binders if they are already in scope. ------ Historical note ------- At one point I tried simply adding the template binders to the in-scope set /without/ cloning them, but that failed in a horribly -obscure way in Trac #14777. Problem was that during matching we look +obscure way in #14777. Problem was that during matching we look up target-term variables in the in-scope set (see Note [Lookup in-scope]). If a target-term variable happens to name-clash with a template variable, that lookup will find the template variable, which -is /utterly/ bogus. In Trac #14777, this transformed a term variable +is /utterly/ bogus. In #14777, this transformed a term variable into a type variable, and then crashed when we wanted its idInfo. ------ End of historical note ------- |