src/tools/yapf/yapf/yapflib/yapf_api.py - cef - Git at Google

 # Copyright 2015-2017 Google Inc. All Rights Reserved.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #
 #     http://www.apache.org/licenses/LICENSE-2.0
 #
 # Unless required by applicable law or agreed to in writing, software
 # distributed under the License is distributed on an "AS IS" BASIS,
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
 """Entry points for YAPF.

 The main APIs that YAPF exposes to drive the reformatting.

   FormatFile(): reformat a file.
   FormatCode(): reformat a string of code.

 These APIs have some common arguments:

   style_config: (string) Either a style name or a path to a file that contains
     formatting style settings. If None is specified, use the default style
     as set in style.DEFAULT_STYLE_FACTORY
   lines: (list of tuples of integers) A list of tuples of lines, [start, end],
     that we want to format. The lines are 1-based indexed. It can be used by
     third-party code (e.g., IDEs) when reformatting a snippet of code rather
     than a whole file.
   print_diff: (bool) Instead of returning the reformatted source, return a
     diff that turns the formatted source into reformatter source.
   verify: (bool) True if reformatted code should be verified for syntax.
 """

 import difflib
 import re
 import sys

 from lib2to3.pgen2 import tokenize

 from yapf.yapflib import blank_line_calculator
 from yapf.yapflib import comment_splicer
 from yapf.yapflib import continuation_splicer
 from yapf.yapflib import file_resources
 from yapf.yapflib import py3compat
 from yapf.yapflib import pytree_unwrapper
 from yapf.yapflib import pytree_utils
 from yapf.yapflib import reformatter
 from yapf.yapflib import split_penalty
 from yapf.yapflib import style
 from yapf.yapflib import subtype_assigner


 def FormatFile(filename,
                style_config=None,
                lines=None,
                print_diff=False,
                verify=False,
                in_place=False,
                logger=None):
   """Format a single Python file and return the formatted code.

   Arguments:
     filename: (unicode) The file to reformat.
     in_place: (bool) If True, write the reformatted code back to the file.
     logger: (io streamer) A stream to output logging.
     remaining arguments: see comment at the top of this module.

   Returns:
     Tuple of (reformatted_code, encoding, changed). reformatted_code is None if
     the file is sucessfully written to (having used in_place). reformatted_code
     is a diff if print_diff is True.

   Raises:
     IOError: raised if there was an error reading the file.
     ValueError: raised if in_place and print_diff are both specified.
   """
   _CheckPythonVersion()

   if in_place and print_diff:
     raise ValueError('Cannot pass both in_place and print_diff.')

   original_source, newline, encoding = ReadFile(filename, logger)
   reformatted_source, changed = FormatCode(
       original_source,
       style_config=style_config,
       filename=filename,
       lines=lines,
       print_diff=print_diff,
       verify=verify)
   if reformatted_source.rstrip('\n'):
     lines = reformatted_source.rstrip('\n').split('\n')
     reformatted_source = newline.join(line for line in lines) + newline
   if in_place:
     if original_source and original_source != reformatted_source:
       file_resources.WriteReformattedCode(filename, reformatted_source,
                                           in_place, encoding)
     return None, encoding, changed

   return reformatted_source, encoding, changed


 def FormatCode(unformatted_source,
                filename='<unknown>',
                style_config=None,
                lines=None,
                print_diff=False,
                verify=False):
   """Format a string of Python code.

   This provides an alternative entry point to YAPF.

   Arguments:
     unformatted_source: (unicode) The code to format.
     filename: (unicode) The name of the file being reformatted.
     remaining arguments: see comment at the top of this module.

   Returns:
     Tuple of (reformatted_source, changed). reformatted_source conforms to the
     desired formatting style. changed is True if the source changed.
   """
   _CheckPythonVersion()
   style.SetGlobalStyle(style.CreateStyleFromConfig(style_config))
   if not unformatted_source.endswith('\n'):
     unformatted_source += '\n'
   tree = pytree_utils.ParseCodeToTree(unformatted_source)

   # Run passes on the tree, modifying it in place.
   comment_splicer.SpliceComments(tree)
   continuation_splicer.SpliceContinuations(tree)
   subtype_assigner.AssignSubtypes(tree)
   split_penalty.ComputeSplitPenalties(tree)
   blank_line_calculator.CalculateBlankLines(tree)

   uwlines = pytree_unwrapper.UnwrapPyTree(tree)
   for uwl in uwlines:
     uwl.CalculateFormattingInformation()

   _MarkLinesToFormat(uwlines, lines)
   reformatted_source = reformatter.Reformat(uwlines, verify)

   if unformatted_source == reformatted_source:
     return '' if print_diff else reformatted_source, False

   code_diff = _GetUnifiedDiff(
       unformatted_source, reformatted_source, filename=filename)

   if print_diff:
     return code_diff, code_diff != ''

   return reformatted_source, True


 def _CheckPythonVersion():  # pragma: no cover
   errmsg = 'yapf is only supported for Python 2.7 or 3.4+'
   if sys.version_info[0] == 2:
     if sys.version_info[1] < 7:
       raise RuntimeError(errmsg)
   elif sys.version_info[0] == 3:
     if sys.version_info[1] < 4:
       raise RuntimeError(errmsg)


 def ReadFile(filename, logger=None):
   """Read the contents of the file.

   An optional logger can be specified to emit messages to your favorite logging
   stream. If specified, then no exception is raised. This is external so that it
   can be used by third-party applications.

   Arguments:
     filename: (unicode) The name of the file.
     logger: (function) A function or lambda that takes a string and emits it.

   Returns:
     The contents of filename.

   Raises:
     IOError: raised if there was an error reading the file.
   """
   try:
     with open(filename, 'rb') as fd:
       encoding = tokenize.detect_encoding(fd.readline)[0]
   except IOError as err:
     if logger:
       logger(err)
     raise

   try:
     # Preserves line endings.
     with py3compat.open_with_encoding(
         filename, mode='r', encoding=encoding, newline='') as fd:
       lines = fd.readlines()

     line_ending = file_resources.LineEnding(lines)
     source = '\n'.join(line.rstrip('\r\n') for line in lines) + '\n'
     return source, line_ending, encoding
   except IOError as err:  # pragma: no cover
     if logger:
       logger(err)
     raise


 DISABLE_PATTERN = r'^#.*\byapf:\s*disable\b'
 ENABLE_PATTERN = r'^#.*\byapf:\s*enable\b'


 def _MarkLinesToFormat(uwlines, lines):
   """Skip sections of code that we shouldn't reformat."""
   if lines:
     for uwline in uwlines:
       uwline.disable = True

     # Sort and combine overlapping ranges.
     lines = sorted(lines)
     line_ranges = [lines[0]] if len(lines[0]) else []
     index = 1
     while index < len(lines):
       current = line_ranges[-1]
       if lines[index][0] <= current[1]:
         # The ranges overlap, so combine them.
         line_ranges[-1] = (current[0], max(lines[index][1], current[1]))
       else:
         line_ranges.append(lines[index])
       index += 1

     # Mark lines to format as not being disabled.
     index = 0
     for start, end in sorted(line_ranges):
       while index < len(uwlines) and uwlines[index].last.lineno < start:
         index += 1
       if index >= len(uwlines):
         break

       while index < len(uwlines):
         if uwlines[index].lineno > end:
           break
         if (uwlines[index].lineno >= start or
             uwlines[index].last.lineno >= start):
           uwlines[index].disable = False
         index += 1

   # Now go through the lines and disable any lines explicitly marked as
   # disabled.
   index = 0
   while index < len(uwlines):
     uwline = uwlines[index]
     if uwline.is_comment:
       if _DisableYAPF(uwline.first.value.strip()):
         index += 1
         while index < len(uwlines):
           uwline = uwlines[index]
           if uwline.is_comment and _EnableYAPF(uwline.first.value.strip()):
             break
           uwline.disable = True
           index += 1
     elif re.search(DISABLE_PATTERN, uwline.last.value.strip(), re.IGNORECASE):
       uwline.disable = True
     index += 1


 def _DisableYAPF(line):
   return (
       re.search(DISABLE_PATTERN, line.split('\n')[0].strip(), re.IGNORECASE) or
       re.search(DISABLE_PATTERN, line.split('\n')[-1].strip(), re.IGNORECASE))


 def _EnableYAPF(line):
   return (
       re.search(ENABLE_PATTERN, line.split('\n')[0].strip(), re.IGNORECASE) or
       re.search(ENABLE_PATTERN, line.split('\n')[-1].strip(), re.IGNORECASE))


 def _GetUnifiedDiff(before, after, filename='code'):
   """Get a unified diff of the changes.

   Arguments:
     before: (unicode) The original source code.
     after: (unicode) The reformatted source code.
     filename: (unicode) The code's filename.

   Returns:
     The unified diff text.
   """
   before = before.splitlines()
   after = after.splitlines()
   return '\n'.join(
       difflib.unified_diff(
           before,
           after,
           filename,
           filename,
           '(original)',
           '(reformatted)',
           lineterm='')) + '\n'
	# Copyright 2015-2017 Google Inc. All Rights Reserved.
	#
	# Licensed under the Apache License, Version 2.0 (the "License");
	# you may not use this file except in compliance with the License.
	# You may obtain a copy of the License at
	#
	# http://www.apache.org/licenses/LICENSE-2.0
	#
	# Unless required by applicable law or agreed to in writing, software
	# distributed under the License is distributed on an "AS IS" BASIS,
	# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	# See the License for the specific language governing permissions and
	# limitations under the License.
	"""Entry points for YAPF.

	The main APIs that YAPF exposes to drive the reformatting.

	FormatFile(): reformat a file.
	FormatCode(): reformat a string of code.

	These APIs have some common arguments:

	style_config: (string) Either a style name or a path to a file that contains
	formatting style settings. If None is specified, use the default style
	as set in style.DEFAULT_STYLE_FACTORY
	lines: (list of tuples of integers) A list of tuples of lines, [start, end],
	that we want to format. The lines are 1-based indexed. It can be used by
	third-party code (e.g., IDEs) when reformatting a snippet of code rather
	than a whole file.
	print_diff: (bool) Instead of returning the reformatted source, return a
	diff that turns the formatted source into reformatter source.
	verify: (bool) True if reformatted code should be verified for syntax.
	"""

	import difflib
	import re
	import sys

	from lib2to3.pgen2 import tokenize

	from yapf.yapflib import blank_line_calculator
	from yapf.yapflib import comment_splicer
	from yapf.yapflib import continuation_splicer
	from yapf.yapflib import file_resources
	from yapf.yapflib import py3compat
	from yapf.yapflib import pytree_unwrapper
	from yapf.yapflib import pytree_utils
	from yapf.yapflib import reformatter
	from yapf.yapflib import split_penalty
	from yapf.yapflib import style
	from yapf.yapflib import subtype_assigner


	def FormatFile(filename,
	style_config=None,
	lines=None,
	print_diff=False,
	verify=False,
	in_place=False,
	logger=None):
	"""Format a single Python file and return the formatted code.

	Arguments:
	filename: (unicode) The file to reformat.
	in_place: (bool) If True, write the reformatted code back to the file.
	logger: (io streamer) A stream to output logging.
	remaining arguments: see comment at the top of this module.

	Returns:
	Tuple of (reformatted_code, encoding, changed). reformatted_code is None if
	the file is sucessfully written to (having used in_place). reformatted_code
	is a diff if print_diff is True.

	Raises:
	IOError: raised if there was an error reading the file.
	ValueError: raised if in_place and print_diff are both specified.
	"""
	_CheckPythonVersion()

	if in_place and print_diff:
	raise ValueError('Cannot pass both in_place and print_diff.')

	original_source, newline, encoding = ReadFile(filename, logger)
	reformatted_source, changed = FormatCode(
	original_source,
	style_config=style_config,
	filename=filename,
	lines=lines,
	print_diff=print_diff,
	verify=verify)
	if reformatted_source.rstrip('\n'):
	lines = reformatted_source.rstrip('\n').split('\n')
	reformatted_source = newline.join(line for line in lines) + newline
	if in_place:
	if original_source and original_source != reformatted_source:
	file_resources.WriteReformattedCode(filename, reformatted_source,
	in_place, encoding)
	return None, encoding, changed

	return reformatted_source, encoding, changed


	def FormatCode(unformatted_source,
	filename='<unknown>',
	style_config=None,
	lines=None,
	print_diff=False,
	verify=False):
	"""Format a string of Python code.

	This provides an alternative entry point to YAPF.

	Arguments:
	unformatted_source: (unicode) The code to format.
	filename: (unicode) The name of the file being reformatted.
	remaining arguments: see comment at the top of this module.

	Returns:
	Tuple of (reformatted_source, changed). reformatted_source conforms to the
	desired formatting style. changed is True if the source changed.
	"""
	_CheckPythonVersion()
	style.SetGlobalStyle(style.CreateStyleFromConfig(style_config))
	if not unformatted_source.endswith('\n'):
	unformatted_source += '\n'
	tree = pytree_utils.ParseCodeToTree(unformatted_source)

	# Run passes on the tree, modifying it in place.
	comment_splicer.SpliceComments(tree)
	continuation_splicer.SpliceContinuations(tree)
	subtype_assigner.AssignSubtypes(tree)
	split_penalty.ComputeSplitPenalties(tree)
	blank_line_calculator.CalculateBlankLines(tree)

	uwlines = pytree_unwrapper.UnwrapPyTree(tree)
	for uwl in uwlines:
	uwl.CalculateFormattingInformation()

	_MarkLinesToFormat(uwlines, lines)
	reformatted_source = reformatter.Reformat(uwlines, verify)

	if unformatted_source == reformatted_source:
	return '' if print_diff else reformatted_source, False

	code_diff = _GetUnifiedDiff(
	unformatted_source, reformatted_source, filename=filename)

	if print_diff:
	return code_diff, code_diff != ''

	return reformatted_source, True


	def _CheckPythonVersion(): # pragma: no cover
	errmsg = 'yapf is only supported for Python 2.7 or 3.4+'
	if sys.version_info[0] == 2:
	if sys.version_info[1] < 7:
	raise RuntimeError(errmsg)
	elif sys.version_info[0] == 3:
	if sys.version_info[1] < 4:
	raise RuntimeError(errmsg)


	def ReadFile(filename, logger=None):
	"""Read the contents of the file.

	An optional logger can be specified to emit messages to your favorite logging
	stream. If specified, then no exception is raised. This is external so that it
	can be used by third-party applications.

	Arguments:
	filename: (unicode) The name of the file.
	logger: (function) A function or lambda that takes a string and emits it.

	Returns:
	The contents of filename.

	Raises:
	IOError: raised if there was an error reading the file.
	"""
	try:
	with open(filename, 'rb') as fd:
	encoding = tokenize.detect_encoding(fd.readline)[0]
	except IOError as err:
	if logger:
	logger(err)
	raise

	try:
	# Preserves line endings.
	with py3compat.open_with_encoding(
	filename, mode='r', encoding=encoding, newline='') as fd:
	lines = fd.readlines()

	line_ending = file_resources.LineEnding(lines)
	source = '\n'.join(line.rstrip('\r\n') for line in lines) + '\n'
	return source, line_ending, encoding
	except IOError as err: # pragma: no cover
	if logger:
	logger(err)
	raise


	DISABLE_PATTERN = r'^#.\byapf:\sdisable\b'
	ENABLE_PATTERN = r'^#.\byapf:\senable\b'


	def _MarkLinesToFormat(uwlines, lines):
	"""Skip sections of code that we shouldn't reformat."""
	if lines:
	for uwline in uwlines:
	uwline.disable = True

	# Sort and combine overlapping ranges.
	lines = sorted(lines)
	line_ranges = [lines[0]] if len(lines[0]) else []
	index = 1
	while index < len(lines):
	current = line_ranges[-1]
	if lines[index][0] <= current[1]:
	# The ranges overlap, so combine them.
	line_ranges[-1] = (current[0], max(lines[index][1], current[1]))
	else:
	line_ranges.append(lines[index])
	index += 1

	# Mark lines to format as not being disabled.
	index = 0
	for start, end in sorted(line_ranges):
	while index < len(uwlines) and uwlines[index].last.lineno < start:
	index += 1
	if index >= len(uwlines):
	break

	while index < len(uwlines):
	if uwlines[index].lineno > end:
	break
	if (uwlines[index].lineno >= start or
	uwlines[index].last.lineno >= start):
	uwlines[index].disable = False
	index += 1

	# Now go through the lines and disable any lines explicitly marked as
	# disabled.
	index = 0
	while index < len(uwlines):
	uwline = uwlines[index]
	if uwline.is_comment:
	if _DisableYAPF(uwline.first.value.strip()):
	index += 1
	while index < len(uwlines):
	uwline = uwlines[index]
	if uwline.is_comment and _EnableYAPF(uwline.first.value.strip()):
	break
	uwline.disable = True
	index += 1
	elif re.search(DISABLE_PATTERN, uwline.last.value.strip(), re.IGNORECASE):
	uwline.disable = True
	index += 1


	def _DisableYAPF(line):
	return (
	re.search(DISABLE_PATTERN, line.split('\n')[0].strip(), re.IGNORECASE) or
	re.search(DISABLE_PATTERN, line.split('\n')[-1].strip(), re.IGNORECASE))


	def _EnableYAPF(line):
	return (
	re.search(ENABLE_PATTERN, line.split('\n')[0].strip(), re.IGNORECASE) or
	re.search(ENABLE_PATTERN, line.split('\n')[-1].strip(), re.IGNORECASE))


	def _GetUnifiedDiff(before, after, filename='code'):
	"""Get a unified diff of the changes.

	Arguments:
	before: (unicode) The original source code.
	after: (unicode) The reformatted source code.
	filename: (unicode) The code's filename.

	Returns:
	The unified diff text.
	"""
	before = before.splitlines()
	after = after.splitlines()
	return '\n'.join(
	difflib.unified_diff(
	before,
	after,
	filename,
	filename,
	'(original)',
	'(reformatted)',
	lineterm='')) + '\n'