better repl reader

repl.py

@@ -1,10 +1,27 @@
 import wasp.parser as parser
 
-line = raw_input(">> ")
-while line != "":
-    ptree = parser.parse(line)
-    print " ^ %s" % ptree
-    ast = ptree.ast()
-    print " ‡ %r" % ast
-    #tree.eval()
-    line = raw_input(">> ")
+
+class Reader(object):
+    def __init__(self):
+        pass
+
+    def __iter__(self):
+        return self
+
+    def __next__(self):
+        return self.next()
+
+    def next(self):
+        try:
+            return raw_input(">> ")
+        except EOFError:
+            raise StopIteration()
+
+
+if __name__ == "__main__":
+    for line in Reader():
+        ptree = parser.parse(line)
+        print " ^ %s" % ptree
+        ast = ptree.ast()
+        print " ‡ %r" % ast
+        #ast.eval()