From: simonpj@microsoft.com <unknown>
Date: Sun, 22 Apr 2007 21:06:14 +0000 (+0000)
Subject: Comments only (concerning rewrite rules)
X-Git-Tag: 2007-05-06~135
X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=commitdiff_plain;h=618380a7fa2ca7b75b2b6a5bfa7eac4a86941510

Comments only (concerning rewrite rules)
---

diff --git a/compiler/coreSyn/CoreSyn.lhs b/compiler/coreSyn/CoreSyn.lhs
index 9b9d8fae..4ec954c 100644
--- 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_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