1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
|
# Copyright 2006 Google, Inc. All Rights Reserved.
# Licensed to PSF under a Contributor Agreement.
"""Base class for fixers (optional, but recommended)."""
# Python imports
import logging
import itertools
# Get a usable 'set' constructor
try:
set
except NameError:
from sets import Set as set
# Local imports
from ..patcomp import PatternCompiler
from .. import pygram
class BaseFix(object):
"""Optional base class for fixers.
The subclass name must be FixFooBar where FooBar is the result of
removing underscores and capitalizing the words of the fix name.
For example, the class name for a fixer named 'has_key' should be
FixHasKey.
"""
PATTERN = None # Most subclasses should override with a string literal
pattern = None # Compiled pattern, set by compile_pattern()
options = None # Options object passed to initializer
filename = None # The filename (set by set_filename)
logger = None # A logger (set by set_filename)
numbers = itertools.count(1) # For new_name()
used_names = set() # A set of all used NAMEs
order = "post" # Does the fixer prefer pre- or post-order traversal
explicit = False # Is this ignored by refactor.py -f all?
# Shortcut for access to Python grammar symbols
syms = pygram.python_symbols
def __init__(self, options, log):
"""Initializer. Subclass may override.
Args:
options: an optparse.Values instance which can be used
to inspect the command line options.
log: a list to append warnings and other messages to.
"""
self.options = options
self.log = log
self.compile_pattern()
def compile_pattern(self):
"""Compiles self.PATTERN into self.pattern.
Subclass may override if it doesn't want to use
self.{pattern,PATTERN} in .match().
"""
if self.PATTERN is not None:
self.pattern = PatternCompiler().compile_pattern(self.PATTERN)
def set_filename(self, filename):
"""Set the filename, and a logger derived from it.
The main refactoring tool should call this.
"""
self.filename = filename
self.logger = logging.getLogger(filename)
def match(self, node):
"""Returns match for a given parse tree node.
Should return a true or false object (not necessarily a bool).
It may return a non-empty dict of matching sub-nodes as
returned by a matching pattern.
Subclass may override.
"""
results = {"node": node}
return self.pattern.match(node, results) and results
def transform(self, node, results):
"""Returns the transformation for a given parse tree node.
Args:
node: the root of the parse tree that matched the fixer.
results: a dict mapping symbolic names to part of the match.
Returns:
None, or a node that is a modified copy of the
argument node. The node argument may also be modified in-place to
effect the same change.
Subclass *must* override.
"""
raise NotImplementedError()
def parenthesize(self, node):
"""Wrapper around pygram.parenthesize()."""
return pygram.parenthesize(node)
def new_name(self, template="xxx_todo_changeme"):
"""Return a string suitable for use as an identifier
The new name is guaranteed not to conflict with other identifiers.
"""
name = template
while name in self.used_names:
name = template + str(next(self.numbers))
self.used_names.add(name)
return name
def log_message(self, message):
if self.first_log:
self.first_log = False
self.log.append("### In file %s ###" % self.filename)
self.log.append(message)
def cannot_convert(self, node, reason=None):
"""Warn the user that a given chunk of code is not valid Python 3,
but that it cannot be converted automatically.
First argument is the top-level node for the code in question.
Optional second argument is why it can't be converted.
"""
lineno = node.get_lineno()
for_output = node.clone()
for_output.set_prefix("")
msg = "Line %d: could not convert: %s"
self.log_message(msg % (lineno, for_output))
if reason:
self.log_message(reason)
def warning(self, node, reason):
"""Used for warning the user about possible uncertainty in the
translation.
First argument is the top-level node for the code in question.
Optional second argument is why it can't be converted.
"""
lineno = node.get_lineno()
self.log_message("Line %d: %s" % (lineno, reason))
def start_tree(self, tree, filename):
"""Some fixers need to maintain tree-wide state.
This method is called once, at the start of tree fix-up.
tree - the root node of the tree to be processed.
filename - the name of the file the tree came from.
"""
self.used_names = tree.used_names
self.set_filename(filename)
self.numbers = itertools.count(1)
self.first_log = True
def finish_tree(self, tree, filename):
"""Some fixers need to maintain tree-wide state.
This method is called once, at the conclusion of tree fix-up.
tree - the root node of the tree to be processed.
filename - the name of the file the tree came from.
"""
pass
|
