# HG changeset patch
# User Adam Chlipala <adam@chlipala.net>
# Date 1417659697 18000
# Node ID 9f65e2188d3c17262cd61f66a826a057252bcbbc
# Parent  1b76ae703cbbc43884fffc7b9be7e1351a094801
MonoOpt: remove concatenation with empty string

diff -r 1b76ae703cbb -r 9f65e2188d3c src/mono_opt.sml
--- a/src/mono_opt.sml	Wed Dec 03 21:06:15 2014 -0500
+++ b/src/mono_opt.sml	Wed Dec 03 21:21:37 2014 -0500
@@ -166,6 +166,9 @@
             e
 
       | EFfiApp ("Basis", "strcat", [(e1, _), (e2, _)]) => exp (EStrcat (e1, e2))
+
+      | EStrcat (e1, (EPrim (Prim.String (_, "")), _)) => #1 e1
+      | EStrcat ((EPrim (Prim.String (_, "")), _), e2) => #1 e2
            
       | EStrcat ((EPrim (Prim.String (Prim.Html, s1)), loc), (EPrim (Prim.String (Prim.Html, s2)), _)) =>
         let