# HG changeset patch
# User Jeff Hammel <jhammel@mozilla.com>
# Date 1307115089 25200
# Node ID 325dccc383086d8cbcde5aa8663cd5aa3b1af68d
# Parent  4b07bb71c2184e6c74c95810a813127aa6798664
begin using subclasses for tokens; the eventual goal is that a token class will know everything it can about what it is and the parser just knows about what tokens are

diff -r 4b07bb71c218 -r 325dccc38308 expr.py
--- a/expr.py	Fri Jun 03 08:24:48 2011 -0700
+++ b/expr.py	Fri Jun 03 08:31:29 2011 -0700
@@ -82,6 +82,11 @@
     # lowest left binding power, always ends parsing
     lbp = 0
 
+class bool_token(literal_token):
+    def __init__(self, value):
+        value = {'true':True, 'false':False}[value]
+        literal_token.__init__(self, value)
+
 precedence = [(end_token, rparen_token),
               (or_op_token,),
               (and_op_token,),
@@ -106,7 +111,7 @@
         Lex the input text into tokens and yield them in sequence.
         """
         # scanner callbacks
-        def bool_(scanner, t): return literal_token({'true':True, 'false':False}[t])
+        def bool_(scanner, t): return bool_token(t)
         def identifier(scanner, t): return ident_token(t)
         def integer(scanner, t): return literal_token(int(t))
         def eq(scanner, t): return eq_op_token()