From 0c72a3ada46ae38fef4d800423ba046f99c119c6 Mon Sep 17 00:00:00 2001
From: "simonpj@microsoft.com" <unknown>
Date: Fri, 9 Apr 2010 16:55:57 +0000
Subject: [PATCH] Fix Trac #3964: view patterns in DsArrows

Just a missing case; I've eliminated the catch-all so
that we get a warning next time we extend HsPat
---
 compiler/deSugar/DsArrows.lhs |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/compiler/deSugar/DsArrows.lhs b/compiler/deSugar/DsArrows.lhs
index b1a4c59..d50aa3e 100644
--- a/compiler/deSugar/DsArrows.lhs
+++ b/compiler/deSugar/DsArrows.lhs
@@ -1066,5 +1066,6 @@ collectl (L _ pat) bndrs
     go (SigPatOut pat _)          = collectl pat bndrs
     go (TypePat _)                = bndrs
     go (CoPat _ pat _)            = collectl (noLoc pat) bndrs
-    go p                          = pprPanic "collectl/go" (ppr p)
+    go (ViewPat _ pat _)          = collectl pat bndrs
+    go p@(QuasiQuotePat {})       = pprPanic "collectl/go" (ppr p)
 \end{code}
-- 
1.7.10.4