From 22c4a046e715f849bf52ad591df8bfda0332f892 Mon Sep 17 00:00:00 2001
From: aarne <aarne@cs.chalmers.se>
Date: Mon, 26 Mar 2007 21:13:37 +0000
Subject: [PATCH] started eval

---
 devel/compiler/Eval.hs | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)
 create mode 100644 devel/compiler/Eval.hs

diff --git a/devel/compiler/Eval.hs b/devel/compiler/Eval.hs
new file mode 100644
index 000000000..e62336ede
--- /dev/null
+++ b/devel/compiler/Eval.hs
@@ -0,0 +1,22 @@
+module Eval where
+
+import AbsSrc
+import AbsTgt
+
+import qualified Data.Map as M
+
+eval :: Env -> Exp -> Val
+eval env e = case e of
+  ECon c -> look c
+  EStr s -> VTok s
+  ECat x y -> VCat (ev x) (ev y)
+ where 
+   look = lookCons env
+   ev = eval env
+
+data Env = Env {
+  constants :: M.Map Ident Val
+  }
+
+lookCons :: Env -> Ident -> Val
+lookCons env c = maybe undefined id $ M.lookup c $ constants env