Comments only (concerning rewrite rules)

diff --git a/compiler/coreSyn/CoreSyn.lhs b/compiler/coreSyn/CoreSyn.lhs
index 9b9d8fa..4ec954c 100644 (file)
--- a/compiler/coreSyn/CoreSyn.lhs
+++ b/compiler/coreSyn/CoreSyn.lhs
@@ -228,8 +228,13 @@ data CoreRule
        ru_name :: RuleName,    -- and suchlike.  It has no free variables.
        ru_fn :: Name,          -- Name of the Id at 
                                -- the head of this rule
        ru_name :: RuleName,    -- and suchlike.  It has no free variables.
        ru_fn :: Name,          -- Name of the Id at 
                                -- the head of this rule

-       ru_nargs :: Int,        -- Number of args that ru_try expects
+       ru_nargs :: Int,        -- Number of args that ru_try expects,
+                               -- including type args

        ru_try  :: [CoreExpr] -> Maybe CoreExpr }
        ru_try  :: [CoreExpr] -> Maybe CoreExpr }

+               -- This function does the rewrite.  It given too many
+               -- arguments, it simply discards them; the returned CoreExpr
+               -- is just the rewrite of ru_fn applied to the first ru_nargs args
+               -- See Note [Extra args in rule matching] in Rules.lhs

 
 isBuiltinRule (BuiltinRule {}) = True
 isBuiltinRule _                       = False
 
 isBuiltinRule (BuiltinRule {}) = True
 isBuiltinRule _                       = False