Checkpoint. 218 tests are okay; 53 are failing. Done so far:

- all classes are new-style (but ripping out classobject.[ch] isn't done)
- int/int -> float
- all exceptions must derive from BaseException
- absolute import
- 'as' and 'with' are keywords

Grammar/Grammar

@@ -7,18 +7,6 @@
 #        with someone who can; ask around on python-dev for help.  Fred
 #        Drake <fdrake@acm.org> will probably be listening there.
 
-# Commands for Kees Blom's railroad program
-#diagram:token NAME
-#diagram:token NUMBER
-#diagram:token STRING
-#diagram:token NEWLINE
-#diagram:token ENDMARKER
-#diagram:token INDENT
-#diagram:output\input python.bla
-#diagram:token DEDENT
-#diagram:output\textwidth 20.04cm\oddsidemargin  0.0cm\evensidemargin 0.0cm
-#diagram:rules
-
 # Start symbols for the grammar:
 #	single_input is a single interactive statement;
 #	file_input is a module or sequence of commands read from an input file;
@@ -61,8 +49,8 @@ import_stmt: import_name | import_from
 import_name: 'import' dotted_as_names
 import_from: ('from' ('.'* dotted_name | '.')
               'import' ('*' | '(' import_as_names ')' | import_as_names))
-import_as_name: NAME [('as' | NAME) NAME]
-dotted_as_name: dotted_name [('as' | NAME) NAME]
+import_as_name: NAME ['as' NAME]
+dotted_as_name: dotted_name ['as' NAME]
 import_as_names: import_as_name (',' import_as_name)* [',']
 dotted_as_names: dotted_as_name (',' dotted_as_name)*
 dotted_name: NAME ('.' NAME)*
@@ -80,7 +68,7 @@ try_stmt: ('try' ':' suite
 	    ['finally' ':' suite] |
 	   'finally' ':' suite))
 with_stmt: 'with' test [ with_var ] ':' suite
-with_var: ('as' | NAME) expr
+with_var: 'as' expr
 # NB compile.c makes sure that the default except clause is last
 except_clause: 'except' [test [',' test]]
 suite: simple_stmt | NEWLINE INDENT stmt+ DEDENT