"""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
"""
from astpprint import printAst
from pprint import pprint
# 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 lib2to3.compiler.ast import *
from lib2to3.compiler import parser
from lib2to3 import symbol
from lib2to3.compiler 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, tuple) and not isinstance(ast, list):
# get a terminal node
return ast.context
for child in ast:
if isinstance(child, tuple) or isinstance(child, list):
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):
"""Return a modified parse tree for the given suite text."""
return self.transform(parser.suite(text))
def parseexpr(self, text):
"""Return a modified parse tree for the given expression text."""
return self.transform(parser.expr(text))
def parsefile(self, file):
"""Return a modified parse tree for the contents of the given file."""
if type(file) == type(''):
file = open(file)
return self.parsesuite(file.read())
# --------------------------------------------------------------
#
# PRIVATE METHODS
#
def compile_node(self, node):
### emit a line-number node?
n = node.type
if hasattr(symbol, "encoding_decl"):
if n == symbol.encoding_decl:
self.encoding = node.context
node = node[1]
n = node[0]
if n == symbol.single_input:
return self.single_input(node.children)
if n == symbol.file_input:
return self.file_input(node.children)
if n == symbol.eval_input:
return self.eval_input(node.children)
if n == symbol.lambdef:
return self.lambdef(node.children)
if n == symbol.funcdef:
return self.funcdef(node.children)
if n == symbol.classdef:
return self.classdef(node.children)
raise WalkerError, ('unexpected node type', n)
def single_input(self, node):
### do we want to do anything about being "interactive" ?
# NEWLINE | simple_stmt | compound_stmt NEWLINE
n = node[0].type
if n != token.NEWLINE:
return self.com_stmt(node[0])
return Pass()
def file_input(self, nodelist):
doc = self.get_docstring(nodelist, symbol.file_input)
if doc is not None:
i = 1
else:
i = 0
stmts = []
for node in nodelist[i:]:
if node.type != token.ENDMARKER and node.type != token.NEWLINE:
self.com_append_stmt(stmts, node)
return Module(doc, Stmt(stmts))
def eval_input(self, nodelist):
# from the built-in function input()
### is this sufficient?
return Expression(self.com_node(nodelist[0]))
def decorator_name(self, nodelist):
listlen = len(nodelist)
assert listlen >= 1 and listlen % 2 == 1
item = self.atom_name(nodelist)
i = 1
while i < listlen:
assert nodelist[i].type == token.DOT
assert nodelist[i + 1].type == token.NAME
item = Getattr(item, nodelist[i + 1].value)
i += 2
return item
def decorator(self, nodelist):
# '@' dotted_name [ '(' [arglist] ')' ]
assert len(nodelist) in (3, 5, 6)
assert nodelist[0].type == token.AT
assert nodelist[-1].type == token.NEWLINE
assert nodelist[1].type == symbol.dotted_name
funcname = self.decorator_name(nodelist[1].children)
if len(nodelist) > 3:
assert nodelist[2].type == token.LPAR
expr = self.com_call_function(funcname, nodelist[3])
else:
expr = funcname
return expr
def decorators(self, nodelist):
# decorators: decorator ([NEWLINE] decorator)* NEWLINE
items = []
for dec_nodelist in nodelist:
assert dec_nodelist.type == symbol.decorator
items.append(self.decorator(dec_nodelist.children))
return Decorators(items)
def decorated(self, nodelist):
assert nodelist[0].type == symbol.decorators
if nodelist[1].type == symbol.funcdef:
n = [nodelist[0]] + list(nodelist[1].children)
return self.funcdef(n)
elif nodelist[1].type == symbol.classdef:
decorators = self.decorators(nodelist[0].children)
cls = self.classdef(nodelist[1].children)
cls.decorators = decorators
return cls
raise WalkerError()
def funcdef(self, nodelist):
# -6 -5 -4 -3 -2 -1
# funcdef: [decorators] 'def' NAME parameters ':' suite
# parameters: '(' [varargslist] ')'
if len(nodelist) == 6:
assert nodelist[0].type == symbol.decorators
decorators = self.decorators(nodelist[0].children)
else:
assert len(nodelist) == 5
decorators = None
lineno = nodelist[-4].context
name = nodelist[-4].value
args = nodelist[-3].children[1]
if args.type == symbol.varargslist:
names, defaults, varargs, varkeywords = \
self.com_arglist(args.children)
else:
names = defaults = ()
varargs = False
varkeywords = False
doc = self.get_docstring(nodelist[-1])
# code for function
code = self.com_node(nodelist[-1])
if doc is not None:
assert isinstance(code, Stmt)
assert isinstance(code.nodes[0], Discard)
del code.nodes[0]
return Function(decorators, name, names, defaults,
varargs, varkeywords, doc, code,
lineno=lineno)
def lambdef(self, nodelist):
# lambdef: 'lambda' [varargslist] ':' test
#pprint(nodelist)
if nodelist[1].type == symbol.varargslist:
names, defaults, varargs, varkeywords = \
self.com_arglist(nodelist[1].children)
else:
names = defaults = ()
varargs = False
varkeywords = False
# code for lambda
code = self.com_node(nodelist[-1])
return Lambda(names, defaults, varargs, varkeywords, code,
lineno=nodelist[0].context)
old_lambdef = lambdef
def classdef(self, nodelist):
# classdef: 'class' NAME ['(' [testlist] ')'] ':' suite
name = nodelist[1].value
doc = self.get_docstring(nodelist[-1])
if nodelist[2].type == token.COLON:
bases = []
elif nodelist[3].type == token.RPAR:
bases = []
else:
bases = self.com_bases(nodelist[3])
# code for class
code = self.com_node(nodelist[-1])
if doc is not None:
assert isinstance(code, Stmt)
assert isinstance(code.nodes[0], Discard)
del code.nodes[0]
return Class(name, bases, doc, code, None, lineno=nodelist[1].context)
def stmt(self, nodelist):
return self.com_stmt(nodelist[0])
small_stmt = stmt
flow_stmt = stmt
compound_stmt = stmt
def simple_stmt(self, nodelist):
# small_stmt (';' small_stmt)* [';'] NEWLINE
stmts = []
for i in range(0, len(nodelist), 2):
self.com_append_stmt(stmts, nodelist[i])
return Stmt(stmts)
def parameters(self, nodelist):
raise WalkerError
def varargslist(self, nodelist):
raise WalkerError
def fpdef(self, nodelist):
raise WalkerError
def fplist(self, nodelist):
raise WalkerError
def dotted_name(self, nodelist):
raise WalkerError
def comp_op(self, nodelist):
raise WalkerError
def trailer(self, nodelist):
raise WalkerError
def sliceop(self, nodelist):
raise WalkerError
def argument(self, nodelist):
raise WalkerError
# --------------------------------------------------------------
#
# STATEMENT NODES (invoked by com_node())
#
def expr_stmt(self, nodelist):
# augassign testlist | testlist ('=' testlist)*
en = nodelist[-1]
exprNode = self.lookup_node(en)(en.children)
if len(nodelist) == 1:
return Discard(exprNode, lineno=exprNode.lineno)
if nodelist[1].type == token.EQUAL:
nodesl = []
for i in range(0, len(nodelist) - 2, 2):
nodesl.append(self.com_assign(nodelist[i], OP_ASSIGN))
return Assign(nodesl, exprNode, lineno=nodelist[1].context)
else:
lval = self.com_augassign(nodelist[0])
op = self.com_augassign_op(nodelist[1])
return AugAssign(lval, op.value, exprNode, lineno=op.context)
raise WalkerError, "can't get here"
def print_stmt(self, nodelist):
# print ([ test (',' test)* [','] ] | '>>' test [ (',' test)+ [','] ])
items = []
if len(nodelist) == 1:
start = 1
dest = None
elif nodelist[1].type == token.RIGHTSHIFT:
assert len(nodelist) == 3 \
or nodelist[3].type == token.COMMA
dest = self.com_node(nodelist[2])
start = 4
else:
dest = None
start = 1
for i in range(start, len(nodelist), 2):
items.append(self.com_node(nodelist[i]))
if nodelist[-1].type == token.COMMA:
return Print(items, dest, lineno=nodelist[0].context)
return Printnl(items, dest, True, lineno=nodelist[0].context)
def del_stmt(self, nodelist):
return self.com_assign(nodelist[1], OP_DELETE)
def pass_stmt(self, nodelist):
return Pass(lineno=nodelist[0].context)
def break_stmt(self, nodelist):
return Break(lineno=nodelist[0].context)
def continue_stmt(self, nodelist):
return Continue(lineno=nodelist[0].context)
def return_stmt(self, nodelist):
# return: [testlist]
if len(nodelist) < 2:
return Return(Const(None), lineno=nodelist[0].context)
return Return(self.com_node(nodelist[1]), lineno=nodelist[0].context)
def yield_stmt(self, nodelist):
expr = self.com_node(nodelist[0])
return Discard(expr, lineno=expr.lineno)
def yield_expr(self, nodelist):
if len(nodelist) > 1:
value = self.com_node(nodelist[1])
else:
value = Const(None)
return Yield(value, lineno=nodelist[0].context)
def raise_stmt(self, nodelist):
# raise: [test [',' test [',' test]]]
if len(nodelist) > 5:
expr3 = self.com_node(nodelist[5])
else:
expr3 = None
if len(nodelist) > 3:
expr2 = self.com_node(nodelist[3])
else:
expr2 = None
if len(nodelist) > 1:
expr1 = self.com_node(nodelist[1])
else:
expr1 = None
return Raise(expr1, expr2, expr3, lineno=nodelist[0].context)
def import_stmt(self, nodelist):
# import_stmt: import_name | import_from
assert len(nodelist) == 1
return self.com_node(nodelist[0])
def import_name(self, nodelist):
# import_name: 'import' dotted_as_names
return Import(self.com_dotted_as_names(nodelist[1]),
lineno=nodelist[0].context)
def import_from(self, nodelist):
# import_from: 'from' ('.'* dotted_name | '.') 'import' ('*' |
# '(' import_as_names ')' | import_as_names)
assert nodelist[0].value == 'from'
idx = 1
while nodelist[idx].value == '.':
idx += 1
level = idx - 1
if nodelist[idx].type == symbol.dotted_name:
fromname = self.com_dotted_name(nodelist[idx].children)
idx += 1
else:
fromname = ""
assert nodelist[idx].value == 'import'
if nodelist[idx + 1].type == token.STAR:
return From(fromname, [('*', None)], level,
lineno=nodelist[0].context)
else:
node = nodelist[idx + 1 + (nodelist[idx + 1].type == token.LPAR)]
return From(fromname, self.com_import_as_names(node), level,
lineno=nodelist[0].context)
def global_stmt(self, nodelist):
# global: NAME (',' NAME)*
names = []
for i in range(1, len(nodelist), 2):
names.append(nodelist[i].value)
return Global(names, lineno=nodelist[0].context)
def exec_stmt(self, nodelist):
# exec_stmt: 'exec' expr ['in' expr [',' expr]]
expr1 = self.com_node(nodelist[1])
if len(nodelist) >= 4:
expr2 = self.com_node(nodelist[3])
if len(nodelist) >= 6:
expr3 = self.com_node(nodelist[5])
else:
expr3 = None
else:
expr2 = expr3 = None
return Exec(expr1, expr2, expr3, lineno=nodelist[0].context)
def assert_stmt(self, nodelist):
# 'assert': test, [',' test]
expr1 = self.com_node(nodelist[1])
if (len(nodelist) == 4):
expr2 = self.com_node(nodelist[3])
else:
expr2 = None
return Assert(expr1, expr2, lineno=nodelist[0].context)
def if_stmt(self, nodelist):
# if: test ':' suite ('elif' test ':' suite)* ['else' ':' suite]
tests = []
for i in range(0, len(nodelist) - 3, 4):
testNode = self.com_node(nodelist[i + 1])
suiteNode = self.com_node(nodelist[i + 3])
tests.append((testNode, suiteNode))
if len(nodelist) % 4 == 3:
elseNode = self.com_node(nodelist[-1])
## elseNode.lineno = nodelist[-1][1].context
else:
elseNode = None
return If(tests, elseNode, lineno=nodelist[0].context)
def while_stmt(self, nodelist):
# 'while' test ':' suite ['else' ':' suite]
testNode = self.com_node(nodelist[1])
bodyNode = self.com_node(nodelist[3])
if len(nodelist) > 4:
elseNode = self.com_node(nodelist[6])
else:
elseNode = None
return While(testNode, bodyNode, elseNode, lineno=nodelist[0].context)
def for_stmt(self, nodelist):
# 'for' exprlist 'in' exprlist ':' suite ['else' ':' suite]
assignNode = self.com_assign(nodelist[1], OP_ASSIGN)
listNode = self.com_node(nodelist[3])
bodyNode = self.com_node(nodelist[5])
if len(nodelist) > 8:
elseNode = self.com_node(nodelist[8])
else:
elseNode = None
return For(assignNode, listNode, bodyNode, elseNode,
lineno=nodelist[0].context)
def try_stmt(self, nodelist):
return self.com_try_except_finally(nodelist)
def with_stmt(self, nodelist):
return self.com_with(nodelist)
def with_var(self, nodelist):
return self.com_with_var(nodelist)
def suite(self, nodelist):
# simple_stmt | NEWLINE INDENT NEWLINE* (stmt NEWLINE*)+ DEDENT
if len(nodelist) == 1:
return self.com_stmt(nodelist[0])
stmts = []
for node in nodelist:
if node.type == symbol.stmt:
self.com_append_stmt(stmts, node)
return Stmt(stmts)
# --------------------------------------------------------------
#
# EXPRESSION NODES (invoked by com_node())
#
def testlist(self, nodelist):
# testlist: expr (',' expr)* [',']
# testlist_safe: test [(',' test)+ [',']]
# exprlist: expr (',' expr)* [',']
return self.com_binary(Tuple, nodelist)
testlist_safe = testlist # XXX
testlist1 = testlist
exprlist = testlist
def testlist_gexp(self, nodelist):
if len(nodelist) == 2 and nodelist[1].type == symbol.gen_for:
test = self.com_node(nodelist[0])
return self.com_generator_expression(test, nodelist[1])
return self.testlist(nodelist)
def test(self, nodelist):
# or_test ['if' or_test 'else' test] | lambdef
if len(nodelist) == 1 and nodelist[0].type == symbol.lambdef:
return self.lambdef(nodelist[0].children)
then = self.com_node(nodelist[0])
if len(nodelist) > 1:
assert len(nodelist) == 5
assert nodelist[1].value == 'if'
assert nodelist[3].value == 'else'
test = self.com_node(nodelist[2])
else_ = self.com_node(nodelist[4])
return IfExp(test, then, else_, lineno=nodelist[1].context)
return then
def or_test(self, nodelist):
# and_test ('or' and_test)* | lambdef
if len(nodelist) == 1 and nodelist[0].type == symbol.lambdef:
return self.lambdef(nodelist[0].children)
return self.com_binary(Or, nodelist)
old_test = or_test
def and_test(self, nodelist):
# not_test ('and' not_test)*
return self.com_binary(And, nodelist)
def not_test(self, nodelist):
# 'not' not_test | comparison
result = self.com_node(nodelist[-1])
if len(nodelist) == 2:
return Not(result, lineno=nodelist[0].context)
return result
def comparison(self, nodelist):
# comparison: expr (comp_op expr)*
node = self.com_node(nodelist[0])
if len(nodelist) == 1:
return node
results = []
for i in range(2, len(nodelist), 2):
nl = nodelist[i-1]
# comp_op: '<' | '>' | '=' | '>=' | '<=' | '<>' | '!=' | '=='
# | 'in' | 'not' 'in' | 'is' | 'is' 'not'
n = nl.children[0]
if n.type == token.NAME:
type = n.value
if len(nl.children) == 2:
if type == 'not':
type = 'not in'
else:
type = 'is not'
else:
type = _cmp_types[n.type]
lineno = nl.children[0].context
results.append((type, self.com_node(nodelist[i])))
# we need a special "compare" node so that we can distinguish
# 3 < x < 5 from (3 < x) < 5
# the two have very different semantics and results (note that the
# latter form is always true)
return Compare(node, results, lineno=lineno)
def expr(self, nodelist):
# xor_expr ('|' xor_expr)*
return self.com_binary(Bitor, nodelist)
def xor_expr(self, nodelist):
# xor_expr ('^' xor_expr)*
return self.com_binary(Bitxor, nodelist)
def and_expr(self, nodelist):
# xor_expr ('&' xor_expr)*
return self.com_binary(Bitand, nodelist)
def shift_expr(self, nodelist):
# shift_expr ('<<'|'>>' shift_expr)*
node = self.com_node(nodelist[0])
for i in range(2, len(nodelist), 2):
right = self.com_node(nodelist[i])
if nodelist[i-1].type == token.LEFTSHIFT:
node = LeftShift(node, right, lineno=nodelist[1].context)
elif nodelist[i-1].type == token.RIGHTSHIFT:
node = RightShift(node, right, lineno=nodelist[1].context)
else:
raise ValueError, "unexpected token: %s" % nodelist[i-1].type
return node
def arith_expr(self, nodelist):
node = self.com_node(nodelist[0])
for i in range(2, len(nodelist), 2):
right = self.com_node(nodelist[i])
if nodelist[i-1].type == token.PLUS:
node = Add(node, right, lineno=nodelist[1].context)
elif nodelist[i-1].type == token.MINUS:
node = Sub(node, right, lineno=nodelist[1].context)
else:
raise ValueError, "unexpected token: %s" % nodelist[i-1][0]
return node
def term(self, nodelist):
node = self.com_node(nodelist[0])
for i in range(2, len(nodelist), 2):
right = self.com_node(nodelist[i])
t = nodelist[i-1].type
if t == token.STAR:
node = Mul(node, right)
elif t == token.SLASH:
node = Div(node, right)
elif t == token.PERCENT:
node = Mod(node, right)
elif t == token.DOUBLESLASH:
node = FloorDiv(node, right)
else:
raise ValueError, "unexpected token: %s" % t
node.lineno = nodelist[1].context
return node
def factor(self, nodelist):
elt = nodelist[0]
t = elt.type
node = self.lookup_node(nodelist[-1])(nodelist[-1].children)
# need to handle (unary op)constant here...
if t == token.PLUS:
return UnaryAdd(node, lineno=elt.context)
elif t == token.MINUS:
return UnarySub(node, lineno=elt.context)
elif t == token.TILDE:
node = Invert(node, lineno=elt.context)
return node
def power(self, nodelist):
# power: atom trailer* ('**' factor)*
#pprint(nodelist[0])
node = self.com_node(nodelist[0])
for i in range(1, len(nodelist)):
elt = nodelist[i]
if elt.type == token.DOUBLESTAR:
return Power(node, self.com_node(nodelist[i+1]),
lineno=elt.context)
node = self.com_apply_trailer(node, elt)
return node
def atom(self, nodelist):
return self._atom_dispatch[nodelist[0].type](nodelist)
def atom_lpar(self, nodelist):
if nodelist[1].type == token.RPAR:
return Tuple((), lineno=nodelist[0].context)
return self.com_node(nodelist[1])
def atom_lsqb(self, nodelist):
if nodelist[1].type == token.RSQB:
return List((), lineno=nodelist[0].context)
return self.com_list_constructor(nodelist[1])
def atom_lbrace(self, nodelist):
if nodelist[1].type == token.RBRACE:
return Dict((), lineno=nodelist[0].context)
return self.com_dictmaker(nodelist[1])
def atom_backquote(self, nodelist):
return Backquote(self.com_node(nodelist[1]))
def atom_number(self, nodelist):
### need to verify this matches compile.c
k = eval(nodelist[0].value)
return Const(k, lineno=nodelist[0].context)
def decode_literal(self, lit):
if self.encoding:
# this is particularly fragile & a bit of a
# hack... changes in compile.c:parsestr and
# tokenizer.c must be reflected here.
if self.encoding not in ['utf-8', 'iso-8859-1']:
lit = unicode(lit, 'utf-8').encode(self.encoding)
return eval("# coding: %s\n%s" % (self.encoding, lit))
else:
return eval(lit)
def atom_string(self, nodelist):
k = ''
for node in nodelist:
k += self.decode_literal(node.value)
return Const(k, lineno=nodelist[0].context)
def atom_name(self, nodelist):
return Name(nodelist[0].value, lineno=nodelist[0].context)
# --------------------------------------------------------------
#
# INTERNAL PARSING UTILITIES
#
# The use of com_node() introduces a lot of extra stack frames,
# enough to cause a stack overflow compiling test.test_parser with
# the standard interpreter recursionlimit. The com_node() is a
# convenience function that hides the dispatch details, but comes
# at a very high cost. It is more efficient to dispatch directly
# in the callers. In these cases, use lookup_node() and call the
# dispatched node directly.
def lookup_node(self, node):
return self._dispatch[node.type]
def com_node(self, node):
# Note: compile.c has handling in com_node for del_stmt, pass_stmt,
# break_stmt, stmt, small_stmt, flow_stmt, simple_stmt,
# and compound_stmt.
# We'll just dispatch them.
return self._dispatch[node.type](node.children)
def com_NEWLINE(self, *args):
# A ';' at the end of a line can make a NEWLINE token appear
# here, Render it harmless. (genc discards ('discard',
# ('const', xxxx)) Nodes)
return Discard(Const(None))
def com_arglist(self, nodelist):
# varargslist:
# (fpdef ['=' test] ',')* ('*' NAME [',' '**' NAME] | '**' NAME)
# | fpdef ['=' test] (',' fpdef ['=' test])* [',']
# fpdef: NAME | '(' fplist ')'
# fplist: fpdef (',' fpdef)* [',']
names = []
defaults = []
varargs = False
varkeywords = False
i = 0
while i < len(nodelist):
node = nodelist[i]
if node.type == token.STAR or node.type == token.DOUBLESTAR:
if node.type == token.STAR:
node = nodelist[i+1]
if node.type == token.NAME:
names.append(node.value)
varargs = True
i = i + 3
if i < len(nodelist):
# should be DOUBLESTAR
t = nodelist[i].type
if t == token.DOUBLESTAR:
node = nodelist[i+1]
else:
raise ValueError, "unexpected token: %s" % t
names.append(node.value)
varkeywords = True
break
# fpdef: NAME | '(' fplist ')'
names.append(self.com_fpdef(node))
i = i + 1
if i < len(nodelist) and nodelist[i].type == token.EQUAL:
defaults.append(self.com_node(nodelist[i + 1]))
i = i + 2
elif len(defaults):
# we have already seen an argument with default, but here
# came one without
raise SyntaxError, "non-default argument follows default argument"
# skip the comma
i = i + 1
return names, defaults, varargs, varkeywords
def com_fpdef(self, node):
# fpdef: NAME | '(' fplist ')'
if node.children[0].type == token.LPAR:
return self.com_fplist(node.children[1])
return node.children[0].value
def com_fplist(self, node):
# fplist: fpdef (',' fpdef)* [',']
if len(node.children) == 1:
return self.com_fpdef(node.children[0])
list = []
for i in range(0, len(node.children), 2):
list.append(self.com_fpdef(node.children[i]))
return tuple(list)
def com_dotted_name(self, node):
# String together the dotted names and return the string
name = ""
for n in node:
if n.type == token.NAME:
name = name + n.value + '.'
return name[:-1]
def com_dotted_as_name(self, node):
assert node.type == symbol.dotted_as_name
node = node.children
dot = self.com_dotted_name(node[0].children)
if len(node) == 1:
return dot, None
assert node[1].value == 'as'
assert node[2].type == token.NAME
return dot, node[2].value
def com_dotted_as_names(self, node):
assert node.type == symbol.dotted_as_names
node = node.children
names = [self.com_dotted_as_name(node[0])]
for i in range(2, len(node), 2):
names.append(self.com_dotted_as_name(node[i]))
return names
def com_import_as_name(self, node):
assert node.type == symbol.import_as_name
node = node.children
assert node[0].type == token.NAME
if len(node) == 1:
return node[0].value, None
assert node[1].value == 'as', node
assert node[2].type == token.NAME
return node[0].value, node[2].value
def com_import_as_names(self, node):
assert node.type == symbol.import_as_names
node = node.children
names = [self.com_import_as_name(node[0])]
for i in range(2, len(node), 2):
names.append(self.com_import_as_name(node[i]))
return names
def com_bases(self, node):
bases = []
for i in range(0, len(node.children), 2):
bases.append(self.com_node(node.children[i]))
return bases
def com_try_except_finally(self, nodelist):
# ('try' ':' suite
# ((except_clause ':' suite)+ ['else' ':' suite] ['finally' ':' suite]
# | 'finally' ':' suite))
if nodelist[3].type == token.NAME:
# first clause is a finally clause: only try-finally
return TryFinally(self.com_node(nodelist[2]),
self.com_node(nodelist[5]),
lineno=nodelist[0].context)
#tryexcept: [TryNode, [except_clauses], elseNode)]
clauses = []
elseNode = None
finallyNode = None
for i in range(3, len(nodelist), 3):
node = nodelist[i]
if node.type == symbol.except_clause:
#pprint(node.children)
#print len(node.children)
# except_clause: 'except' [expr [(',' | 'as') expr]] */
if len(node.children) > 1:
expr1 = self.com_node(node.children[1])
if len(node.children) > 3:
expr2 = self.com_assign(node.children[3], OP_ASSIGN)
else:
expr2 = None
else:
expr1 = expr2 = None
clauses.append((expr1, expr2, self.com_node(nodelist[i+2])))
if node.type == token.NAME:
if node.value == 'else':
elseNode = self.com_node(nodelist[i+2])
elif node.value == 'finally':
finallyNode = self.com_node(nodelist[i+2])
try_except = TryExcept(self.com_node(nodelist[2]), clauses, elseNode,
lineno=nodelist[0].context)
if finallyNode:
return TryFinally(try_except, finallyNode, lineno=nodelist[0].context)
else:
return try_except
def com_with(self, nodelist):
# with_stmt: 'with' expr [with_var] ':' suite
expr = self.com_node(nodelist[1])
body = self.com_node(nodelist[-1])
if nodelist[2].type == token.COLON:
var = None
else:
var = self.com_assign(nodelist[2].children[1], OP_ASSIGN)
return With(expr, var, body, lineno=nodelist[0].context)
def com_with_var(self, nodelist):
# with_var: 'as' expr
return self.com_node(nodelist[1])
def com_augassign_op(self, node):
assert node.type == symbol.augassign
return node.children[0]
def com_augassign(self, node):
"""Return node suitable for lvalue of augmented assignment
Names, slices, and attributes are the only allowable nodes.
"""
l = self.com_node(node)
if l.__class__ in (Name, Slice, Subscript, Getattr):
return l
raise SyntaxError, "can't assign to %s" % l.__class__.__name__
def com_assign(self, node, assigning):
# return a node suitable for use as an "lvalue"
# loop to avoid trivial recursion
while 1:
t = node.type
if t in (symbol.exprlist, symbol.testlist, symbol.testlist_safe, symbol.testlist_gexp):
if len(node.children) > 1:
return self.com_assign_tuple(node, assigning)
node = node.children[0]
elif t in _assign_types:
if len(node.children) > 1:
raise SyntaxError, "can't assign to operator"
node = node.children[0]
elif t == symbol.power:
if node.children[0].type != symbol.atom:
raise SyntaxError, "can't assign to operator"
if len(node.children) > 1:
primary = self.com_node(node.children[0])
for i in range(1, len(node.children)-1):
ch = node.children[i]
if ch.type == token.DOUBLESTAR:
raise SyntaxError, "can't assign to operator"
primary = self.com_apply_trailer(primary, ch)
return self.com_assign_trailer(primary, node.children[-1],
assigning)
node = node.children[0]
elif t == symbol.atom:
t = node.children[0].type
if t == token.LPAR:
node = node.children[1]
if node.type == token.RPAR:
raise SyntaxError, "can't assign to ()"
elif t == token.LSQB:
node = node.children[1]
if node.type == token.RSQB:
raise SyntaxError, "can't assign to []"
return self.com_assign_list(node, assigning)
elif t == token.NAME:
return self.com_assign_name(node, assigning)
else:
raise SyntaxError, "can't assign to literal"
else:
raise SyntaxError, "bad assignment (%s)" % t
def com_assign_tuple(self, node, assigning):
assigns = []
for i in range(0, len(node.children), 2):
assigns.append(self.com_assign(node.children[i], assigning))
return AssTuple(assigns, lineno=extractLineNo(node))
def com_assign_list(self, node, assigning):
assigns = []
for i in range(0, len(node.children), 2):
if i + 1 < len(node.children):
if node.children[i + 1].type == symbol.comp_for:
raise SyntaxError, "can't assign to list comprehension"
assert node.children[i + 1].type == token.COMMA, node.children[i + 1]
assigns.append(self.com_assign(node.children[i], assigning))
return AssList(assigns, lineno=extractLineNo(node))
def com_assign_name(self, node, assigning):
return AssName(node.children[0].value, assigning, lineno=node.context)
def com_assign_trailer(self, primary, node, assigning):
t = node.children[0].type
if t == token.DOT:
return self.com_assign_attr(primary, node.children[1], assigning)
if t == token.LSQB:
return self.com_subscriptlist(primary, node.children[1], assigning)
if t == token.LPAR:
raise SyntaxError, "can't assign to function call"
raise SyntaxError, "unknown trailer type: %s" % t
def com_assign_attr(self, primary, node, assigning):
return AssAttr(primary, node.value, assigning, lineno=node.context)
def com_binary(self, constructor, nodelist):
"Compile 'NODE (OP NODE)*' into (type, [ node1, ..., nodeN ])."
l = len(nodelist)
if l == 1:
n = nodelist[0]
return self.lookup_node(n)(n.children)
items = []
for i in range(0, l, 2):
n = nodelist[i]
items.append(self.lookup_node(n)(n.children))
return constructor(items, lineno=extractLineNo(nodelist))
def com_stmt(self, node):
result = self.lookup_node(node)(node.children)
assert result is not None
if isinstance(result, Stmt):
return result
return Stmt([result])
def com_append_stmt(self, stmts, node):
result = self.lookup_node(node)(node.children)
assert result is not None
if isinstance(result, Stmt):
stmts.extend(result.nodes)
else:
stmts.append(result)
def com_list_constructor(self, nodelist):
# listmaker: test ( list_for | (',' test)* [','] )
values = []
for i in range(len(nodelist.children)):
if nodelist.children[i].type == symbol.comp_for:
assert len(nodelist.children[i:]) == 1
return self.com_list_comprehension(values[0],
nodelist.children[i])
elif nodelist.children[i].type == token.COMMA:
continue
values.append(self.com_node(nodelist.children[i]))
return List(values, lineno=values[0].lineno)
def com_list_comprehension(self, expr, node):
# list_iter: list_for | list_if
# list_for: 'for' exprlist 'in' testlist [list_iter]
# list_if: 'if' test [list_iter]
# XXX should raise SyntaxError for assignment
lineno = node.children[0].context
fors = []
while node:
t = node.children[0].value
if t == 'for':
assignNode = self.com_assign(node.children[1], OP_ASSIGN)
listNode = self.com_node(node.children[3])
newfor = ListCompFor(assignNode, listNode, [])
newfor.lineno = node.children[0].context
fors.append(newfor)
if len(node.children) == 4:
node = None
else:
node = self.com_list_iter(node.children[4])
elif t == 'if':
test = self.com_node(node.children[1])
newif = ListCompIf(test, lineno=node.children[0].context)
newfor.ifs.append(newif)
if len(node.children) == 2:
node = None
else:
node = self.com_list_iter(node.children[2])
else:
raise SyntaxError, \
("unexpected list comprehension element: %s %d"
% (node, lineno))
return ListComp(expr, fors, lineno=lineno)
def com_list_iter(self, node):
assert node.type == symbol.comp_iter
return node.children[0]
def com_generator_expression(self, expr, node):
# gen_iter: gen_for | gen_if
# gen_for: 'for' exprlist 'in' test [gen_iter]
# gen_if: 'if' test [gen_iter]
lineno = node.children[0].context
fors = []
while node:
t = node.children[0].value
if t == 'for':
assignNode = self.com_assign(node.children[1], OP_ASSIGN)
genNode = self.com_node(node.children[3])
newfor = GenExprFor(assignNode, genNode, [],
lineno=node.children[0].context)
fors.append(newfor)
if (len(node.children)) == 4:
node = None
else:
node = self.com_gen_iter(node.children[4])
elif t == 'if':
test = self.com_node(node.children[1])
newif = GenExprIf(test, lineno=node.children[0].context)
newfor.ifs.append(newif)
if len(node.children) == 2:
node = None
else:
node = self.com_gen_iter(node.children[2])
else:
raise SyntaxError, \
("unexpected generator expression element: %s %d"
% (node, lineno))
fors[0].is_outmost = True
return GenExpr(GenExprInner(expr, fors), lineno=lineno)
def com_gen_iter(self, node):
assert node.type == symbol.gen_iter
return node.children[0]
def com_dictmaker(self, nodelist):
# dictmaker: test ':' test (',' test ':' value)* [',']
items = []
for i in range(0, len(nodelist.children), 4):
items.append((self.com_node(nodelist.children[i]),
self.com_node(nodelist.children[i+2])))
return Dict(items, lineno=items[0][0].lineno)
def com_apply_trailer(self, primaryNode, nodelist):
t = nodelist.children[0].type
if t == token.LPAR:
return self.com_call_function(primaryNode, nodelist.children[1])
if t == token.DOT:
return self.com_select_member(primaryNode, nodelist.children[1])
if t == token.LSQB:
return self.com_subscriptlist(primaryNode, nodelist.children[1], OP_APPLY)
raise SyntaxError, 'unknown node type: %s' % t
def com_select_member(self, primaryNode, nodelist):
if nodelist.type != token.NAME:
raise SyntaxError, "member must be a name"
return Getattr(primaryNode, nodelist.value, lineno=nodelist.context)
def com_call_function(self, primaryNode, nodelist):
if nodelist.type == token.RPAR:
return CallFunc(primaryNode, [], None, None,
lineno=extractLineNo(nodelist))
args = []
kw = 0
star_node = dstar_node = None
len_nodelist = len(nodelist.children)
i = 0
while i < len_nodelist:
node = nodelist.children[i]
if node.type==token.STAR:
if star_node is not None:
raise SyntaxError, 'already have the varargs indentifier'
star_node = self.com_node(nodelist.children[i+1])
i = i + 3
continue
elif node.type==token.DOUBLESTAR:
if dstar_node is not None:
raise SyntaxError, 'already have the kwargs indentifier'
dstar_node = self.com_node(nodelist.children[i+1])
i = i + 3
continue
# positional or named parameters
kw, result = self.com_argument(node, kw, star_node)
if len_nodelist != 2 and isinstance(result, GenExpr) \
and len(node.children) == 3 and node.children[2].type == symbol.gen_for:
printAst(result)
# allow f(x for x in y), but reject f(x for x in y, 1)
# should use f((x for x in y), 1) instead of f(x for x in y, 1)
raise SyntaxError, 'generator expression needs parenthesis'
args.append(result)
i = i + 2
return CallFunc(primaryNode, args, star_node, dstar_node,
lineno=extractLineNo(nodelist))
def com_argument(self, nodelist, kw, star_node):
if len(nodelist.children) == 2 and nodelist.children[1].type == symbol.gen_for:
test = self.com_node(nodelist.children[0])
return 0, self.com_generator_expression(test, nodelist.children[1])
if len(nodelist.children) == 1:
if kw:
raise SyntaxError, "non-keyword arg after keyword arg"
if star_node:
raise SyntaxError, "only named arguments may follow *expression"
return 0, self.com_node(nodelist.children[0])
result = self.com_node(nodelist.children[2])
#print "nodelist"
#pprint(nodelist)
n = nodelist.children[0]
#print len(n.children)
while n.children and len(n.children) == 1 and n.type != token.NAME:
n = n.children[0]
#print n.children
#print "n"
#pprint(n)
if n.type != token.NAME:
raise SyntaxError, "keyword can't be an expression (%s)"%n[0]
node = Keyword(n.value, result, lineno=n.context)
return 1, node
def com_subscriptlist(self, primary, nodelist, assigning):
# slicing: simple_slicing | extended_slicing
# simple_slicing: primary "[" short_slice "]"
# extended_slicing: primary "[" slice_list "]"
# slice_list: slice_item ("," slice_item)* [","]
# backwards compat slice for '[i:j]'
if len(nodelist.children) == 1:
sub = nodelist.children[0]
if (sub.children[0].type == token.COLON or \
(len(sub.children) > 1 and sub.children[1].type == token.COLON)) and \
sub.children[-1].type != symbol.sliceop:
return self.com_slice(primary, sub, assigning)
subscripts = []
for i in range(0, len(nodelist.children), 2):
subscripts.append(self.com_subscript(nodelist.children[i]))
if len(nodelist.children) > 2:
tulplesub = [sub for sub in subscripts \
if not (isinstance(sub, Ellipsis) or \
isinstance(sub, Sliceobj))]
if len(tulplesub) == len(subscripts):
subscripts = [Tuple(subscripts)]
return Subscript(primary, assigning, subscripts,
lineno=extractLineNo(nodelist))
def com_subscript(self, node):
# slice_item: expression | proper_slice | ellipsis
ch = node.children[0]
t = ch.type
if t == token.DOT and node.children[1].type == token.DOT:
return Ellipsis()
if t == token.COLON or len(node.children) > 1:
return self.com_sliceobj(node)
return self.com_node(ch)
def com_sliceobj(self, node):
# proper_slice: short_slice | long_slice
# short_slice: [lower_bound] ":" [upper_bound]
# long_slice: short_slice ":" [stride]
# lower_bound: expression
# upper_bound: expression
# stride: expression
#
# Note: a stride may be further slicing...
items = []
if node.children[0].type == token.COLON:
items.append(Const(None))
i = 1
else:
items.append(self.com_node(node.children[0]))
# i == 2 is a COLON
i = 2
if i < len(node.children) and node.children[i].type == symbol.test:
items.append(self.com_node(node.children[i]))
i = i + 1
else:
items.append(Const(None))
# a short_slice has been built. look for long_slice now by looking
# for strides...
for j in range(i, len(node.children)):
ch = node.children[j]
if ch.children is None or len(ch.children) == 1:
items.append(Const(None))
else:
items.append(self.com_node(ch.children[1]))
return Sliceobj(items, lineno=extractLineNo(node))
def com_slice(self, primary, node, assigning):
# short_slice: [lower_bound] ":" [upper_bound]
lower = upper = None
if len(node.children) == 2:
if node.children[0].type == token.COLON:
upper = self.com_node(node.children[1])
else:
lower = self.com_node(node.children[0])
elif len(node.children) == 3:
lower = self.com_node(node.children[0])
upper = self.com_node(node.children[2])
return Slice(primary, assigning, lower, upper,
lineno=extractLineNo(node))
def get_docstring(self, node, n=None):
if n is None:
n = node.type
node = node.children
if n == symbol.suite:
if len(node) == 1:
return self.get_docstring(node[0])
for sub in node:
if sub.type == symbol.stmt:
return self.get_docstring(sub)
return None
if n == symbol.file_input:
for sub in node:
if sub.type == symbol.stmt:
return self.get_docstring(sub)
return None
if n == symbol.atom:
if node[0].type == token.STRING:
s = ''
for t in node:
s = s + eval(t.value)
return s
return None
if n == symbol.stmt or n == symbol.simple_stmt \
or n == symbol.small_stmt:
return self.get_docstring(node[0])
if n in _doc_nodes and len(node) == 1:
return self.get_docstring(node[0])
return None
_doc_nodes = [
symbol.expr_stmt,
symbol.testlist,
symbol.testlist_safe,
symbol.test,
symbol.or_test,
symbol.and_test,
symbol.not_test,
symbol.comparison,
symbol.expr,
symbol.xor_expr,
symbol.and_expr,
symbol.shift_expr,
symbol.arith_expr,
symbol.term,
symbol.factor,
symbol.power,
]
# comp_op: '<' | '>' | '=' | '>=' | '<=' | '<>' | '!=' | '=='
# | 'in' | 'not' 'in' | 'is' | 'is' 'not'
_cmp_types = {
token.LESS : '<',
token.GREATER : '>',
token.EQEQUAL : '==',
token.EQUAL : '==',
token.LESSEQUAL : '<=',
token.GREATEREQUAL : '>=',
token.NOTEQUAL : '!=',
}
_legal_node_types = [
symbol.funcdef,
symbol.classdef,
symbol.stmt,
symbol.small_stmt,
symbol.flow_stmt,
symbol.simple_stmt,
symbol.compound_stmt,
symbol.expr_stmt,
symbol.print_stmt,
symbol.del_stmt,
symbol.pass_stmt,
symbol.break_stmt,
symbol.continue_stmt,
symbol.return_stmt,
symbol.raise_stmt,
symbol.import_stmt,
symbol.global_stmt,
symbol.exec_stmt,
symbol.assert_stmt,
symbol.if_stmt,
symbol.while_stmt,
symbol.for_stmt,
symbol.try_stmt,
symbol.with_stmt,
symbol.suite,
symbol.testlist,
symbol.testlist_safe,
symbol.test,
symbol.and_test,
symbol.not_test,
symbol.comparison,
symbol.exprlist,
symbol.expr,
symbol.xor_expr,
symbol.and_expr,
symbol.shift_expr,
symbol.arith_expr,
symbol.term,
symbol.factor,
symbol.power,
symbol.atom,
]
if hasattr(symbol, 'yield_stmt'):
_legal_node_types.append(symbol.yield_stmt)
if hasattr(symbol, 'yield_expr'):
_legal_node_types.append(symbol.yield_expr)
_assign_types = [
symbol.test,
symbol.or_test,
symbol.and_test,
symbol.not_test,
symbol.comparison,
symbol.expr,
symbol.xor_expr,
symbol.and_expr,
symbol.shift_expr,
symbol.arith_expr,
symbol.term,
symbol.factor,
]
_names = {}
for k, v in symbol.sym_name.items():
_names[k] = v
for k, v in token.tok_name.items():
_names[k] = v
def debug_tree(tree):
l = []
for elt in tree:
if isinstance(elt, int):
l.append(_names.get(elt, elt))
elif isinstance(elt, str):
l.append(elt)
else:
l.append(debug_tree(elt))
return l
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