X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2FcoreSyn%2FCoreSyn.lhs;h=05de8607bbd20c1e7278c767c7018ed56a2f834e;hb=5109078b26bdbf226acdf1b0fe7c2861a7114571;hp=09e41aaeb959131750a393e0054dea6072c23bda;hpb=479f4cac9815c88e91492913a1247d8c6f53b659;p=ghc-hetmet.git

diff --git a/compiler/coreSyn/CoreSyn.lhs b/compiler/coreSyn/CoreSyn.lhs
index 09e41aa..05de860 100644
--- a/compiler/coreSyn/CoreSyn.lhs
+++ b/compiler/coreSyn/CoreSyn.lhs
@@ -6,6 +6,13 @@
 CoreSyn: A data type for the Haskell compiler midsection
 
 \begin{code}
+{-# OPTIONS -w #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and fix
+-- any warnings in the module. See
+--     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
+-- for details
+
 module CoreSyn (
 	Expr(..), Alt, Bind(..), AltCon(..), Arg, Note(..),
 	CoreExpr, CoreAlt, CoreBind, CoreArg, CoreBndr,
@@ -218,14 +225,23 @@ data CoreRule
 	-- Locality
 	ru_local :: Bool	-- The fn at the head of the rule is
 				-- defined in the same module as the rule
+				-- and is not an implicit Id (like a record sel
+				-- class op, or data con)
+		-- NB: ru_local is *not* used to decide orphan-hood
+		--	c.g. MkIface.coreRuleToIfaceRule
     }
 
   | BuiltinRule {		-- Built-in rules are used for constant folding
 	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 }
+		-- 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