Towards an environment for variables

apauley · Aug 28, 2010 · 02f09d4 · 02f09d4
1 parent 476b902
commit 02f09d4
Showing 1 changed file with 7 additions and 0 deletions.
diff --git a/evalapply.hs b/evalapply.hs
@@ -165,3 +165,10 @@ defineVar envRef var value = do
       env <- readIORef envRef
       writeIORef envRef ((var, valueRef) : env)
       return value
+
+bindVars :: Env -> [(String, LispVal)] -> IO Env
+bindVars envRef bindings = readIORef envRef >>= extendEnv bindings >>= newIORef
+    where extendEnv bindings env = liftM (++ env) (mapM addBinding bindings)
+          addBinding (var, value) = do ref <- newIORef value
+                                       return (var, ref)
+