From: simonpj@microsoft.com <unknown>
Date: Wed, 6 Sep 2006 11:41:55 +0000 (+0000)
Subject: Add comment for the invariant that DataAlt is never a newtype
X-Git-Tag: After_FC_branch_merge~130
X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=commitdiff_plain;h=133d09024cdead191873088b7248f5d96aafe60f;hp=6f873493416ccb4d277377bf031639bc307c8369

Add comment for the invariant that DataAlt is never a newtype
---

diff --git a/compiler/coreSyn/CoreSyn.lhs b/compiler/coreSyn/CoreSyn.lhs
index f83845f..a108945 100644
--- a/compiler/coreSyn/CoreSyn.lhs
+++ b/compiler/coreSyn/CoreSyn.lhs
@@ -112,7 +112,8 @@ type Arg b = Expr b		-- Can be a Type
 
 type Alt b = (AltCon, [b], Expr b)	-- (DEFAULT, [], rhs) is the default alternative
 
-data AltCon = DataAlt DataCon
+data AltCon = DataAlt DataCon	-- Invariant: the DataCon is always from 
+				-- a *data* type, and never from a *newtype*
 	    | LitAlt  Literal
 	    | DEFAULT
 	 deriving (Eq, Ord)