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     #ˆÈË„mï¿É ?÷     #"""Parse tree transformation module.

Transforms Python source code into an abstract syntax tree (AST)
defined in the ast module.

The simplest ways to invoke this module are via parse and parseFile.
parse(buf) -> AST
parseFile(path) -> AST
"""

# Original version written by Greg Stein (gstein@lyra.org)
#                         and Bill Tutt (rassilon@lima.mudlib.org)
# February 1997.
#
# Modifications and improvements for Python 2.0 by Jeremy Hylton and
# Mark Hammond
#
# Some fixes to try to have correct line number on almost all nodes
# (except Module, Discard and Stmt) added by Sylvain Thenault
#
# Portions of this file are:
# Copyright (C) 1997-1998 Greg Stein. All Rights Reserved.
#
# This module is provided under a BSD-ish license. See
#   http://www.opensource.org/licenses/bsd-license.html
# and replace OWNER, ORGANIZATION, and YEAR as appropriate.

from compiler.ast import *
import parser
import symbol
import token

class WalkerError(StandardError):
    pass

from compiler.consts import CO_VARARGS, CO_VARKEYWORDS
from compiler.consts import OP_ASSIGN, OP_DELETE, OP_APPLY

def parseFile(path):
    f = open(path, "U")
    # XXX The parser API tolerates files without a trailing newline,
    # but not strings without a trailing newline.  Always add an extra
    # newline to the file contents, since we're going through the string
    # version of the API.
    src = f.read() + "\n"
    f.close()
    return parse(src)

def parse(buf, mode="exec"):
    if mode == "exec" or mode == "single":
        return Transformer().parsesuite(buf)
    elif mode == "eval":
        return Transformer().parseexpr(buf)
    else:
        raise ValueError("compile() arg 3 must be"
                         " 'exec' or 'eval' or 'single'")

def asList(nodes):
    l = []
    for item in nodes:
        if hasattr(item, "asList"):
            l.append(item.asList())
        else:
            if type(item) is type( (None, None) ):
                l.append(tuple(asList(item)))
            elif type(item) is type( [] ):
                l.append(asList(item))
            else:
                l.append(item)
    return l

def extractLineNo(ast):
    if not isinstance(ast[1], tuple):
        # get a terminal node
        return ast[2]
    for child in ast[1:]:
        if isinstance(child, tuple):
            lineno = extractLineNo(child)
            if lineno is not None:
                return lineno

def Node(*args):
    kind = args[0]
    if kind in nodes:
        try:
            return nodes[kind](*args[1:])
        except TypeError:
            print nodes[kind], len(args), args
            raise
    else:
        raise WalkerError, "Can't find appropriate Node type: %s" % str(args)
        #return apply(ast.Node, args)

class Transformer:
    """Utility object for transforming Python parse trees.

    Exposes the following methods:
        tree = transform(ast_tree)
        tree = parsesuite(text)
        tree = parseexpr(text)
        tree = parsefile(fileob | filename)
    """

    def __init__(self):
        self._dispatch = {}
        for value, name in symbol.sym_name.items():
            if hasattr(self, name):
                self._dispatch[value] = getattr(self, name)
        self._dispatch[token.NEWLINE] = self.com_NEWLINE
        self._atom_dispatch = {token.LPAR: self.atom_lpar,
                               token.LSQB: self.atom_lsqb,
                               token.LBRACE: self.atom_lbrace,
                               token.BACKQUOTE: self.atom_backquote,
                               token.NUMBER: self.atom_number,
                               token.STRING: self.atom_string,
                               token.NAME: self.atom_name,
                               }
        self.encoding = None

    def transform(self, tree):
        """Transform an AST into a modified parse tree."""
        if not (isinstance(tree, tuple) or isinstance(tree, list)):
            tree = parser.st2tuple(tree, line_info=1)
        return self.compile_node(tree)

    def parsesuite(self, text):