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Diffstat (limited to 'compiler/GHC/Core/Rules.hs')
| -rw-r--r-- | compiler/GHC/Core/Rules.hs | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/compiler/GHC/Core/Rules.hs b/compiler/GHC/Core/Rules.hs index 1db2645f51..a8c9cbef5a 100644 --- a/compiler/GHC/Core/Rules.hs +++ b/compiler/GHC/Core/Rules.hs @@ -522,11 +522,14 @@ matchRule :: RuleOpts -> InScopeEnv -> (Activation -> Bool) -- [f,map g x] -- tpl_args -- map (f.g) x) -- rhs -- --- Then the call: matchRule the_rule [e1,map e2 e3] +-- Then the expression +-- map e1 (map e2 e3) e4 +-- results in a call to +-- matchRule the_rule [e1,map e2 e3,e4] -- = Just ("map/map", (\f,g,x -> rhs) e1 e2 e3) -- --- Any 'surplus' arguments in the input are simply put on the end --- of the output. +-- NB: The 'surplus' argument e4 in the input is simply dropped. +-- See Note [Extra args in the target] matchRule opts rule_env _is_active fn args _rough_args (BuiltinRule { ru_try = match_fn }) |