From 0dcc1707ee94e7ab366b8919b2602e0ad4479203 Mon Sep 17 00:00:00 2001
From: darkf <lw9k123@gmail.com>
Date: Wed, 23 Oct 2013 15:15:34 -0700
Subject: [PATCH] implement cons on strings

---
 interp.hs | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/interp.hs b/interp.hs
index 1a14602..cfff587 100644
--- a/interp.hs
+++ b/interp.hs
@@ -199,6 +199,15 @@ patternBindings (IntP n) _ = Nothing
 patternBindings UnitP UnitV = Just M.empty
 patternBindings UnitP _ = Nothing
 
+-- cons on strings
+patternBindings (ConsP x (ListP [])) (StrV (y:[])) = patternBindings x (StrV [y])
+patternBindings (ConsP xp xsp) (StrV (x:xs)) =
+	do
+		xe <- patternBindings xp (StrV [x])
+		xse <- patternBindings xsp $ StrV xs
+		Just $ M.union xe xse
+
+-- cons on lists
 patternBindings (ConsP x (ListP [])) (ListV (y:[])) = patternBindings x y
 patternBindings (ConsP xp xsp) (ListV (x:xs)) =
 	do