change Node to nodes module; use a class hierarchy for node types

parser/Node.py

@@ -1,7 +0,0 @@
-
-class Node(object):
-    def __init__(self, type, children=None, node=None, data=None):
-        self.type = type
-        self.children = children
-        self.node = node
-        self.data = data

parser/nodes.py

@@ -0,0 +1,17 @@
+
+class Node(object):
+    def __init__(self, children=None):
+        self.children = children
+
+class StatementNode(Node):
+    def __init__(self, children=None):
+        Node.__init__(self, children)
+
+class ExprNode(Node):
+    def __init__(self, children=None):
+        Node.__init__(self, children)
+
+class CExprNode(ExprNode):
+    def __init__(self, cstring):
+        ExprNode.__init__(self)
+        self.cstring = cstring

parser/parserules.py

@@ -1,10 +1,10 @@
 
 from lexrules import tokens
-from Node import Node
+from nodes import *
 
 def p_statement(p):
     'statement : expr SEMICOLON'
-    p[0] = Node('statement', [p[1]])
+    p[0] = StatementNode([p[1]])
 
 def p_expr(p):
     'expr : c_expr'
@@ -12,4 +12,4 @@ def p_expr(p):
 
 def p_c_expr(p):
     'c_expr : C LPAREN STRING RPAREN'
-    p[0] = Node('c_expr', data=p[3])
+    p[0] = CExprNode(p[3])