def _GetTextInside()

in cpplint.py [0:0]

• 25 lines of code
• 8 McCabe index (conditional complexity)

def _GetTextInside(text, start_pattern):
    r"""Retrieves all the text between matching open and close parentheses.

  Given a string of lines and a regular expression string, retrieve all the text
  following the expression and between opening punctuation symbols like
  (, [, or {, and the matching close-punctuation symbol. This properly nested
  occurrences of the punctuations, so for the text like
    printf(a(), b(c()));
  a call to _GetTextInside(text, r'printf\(') will return 'a(), b(c())'.
  start_pattern must match string having an open punctuation symbol at the end.

  Args:
    text: The lines to extract text. Its comments and strings must be elided.
           It can be single line and can span multiple lines.
    start_pattern: The regexp string indicating where to start extracting
                   the text.
  Returns:
    The extracted text.
    None if either the opening string or ending punctuation could not be found.
  """
    # TODO(unknown): Audit cpplint.py to see what places could be profitably
    # rewritten to use _GetTextInside (and use inferior regexp matching today).

    # Give opening punctuations to get the matching close-punctuations.
    matching_punctuation = {'(': ')', '{': '}', '[': ']'}
    closing_punctuation = set(matching_punctuation.itervalues())

    # Find the position to start extracting text.
    match = re.search(start_pattern, text, re.M)
    if not match:  # start_pattern not found in text.
        return None
    start_position = match.end(0)

    assert start_position > 0, (
        'start_pattern must ends with an opening punctuation.')
    assert text[start_position - 1] in matching_punctuation, (
        'start_pattern must ends with an opening punctuation.')
    # Stack of closing punctuations we expect to have in text after position.
    punctuation_stack = [matching_punctuation[text[start_position - 1]]]
    position = start_position
    while punctuation_stack and position < len(text):
        if text[position] == punctuation_stack[-1]:
            punctuation_stack.pop()
        elif text[position] in closing_punctuation:
            # A closing punctuation without matching opening punctuations.
            return None
        elif text[position] in matching_punctuation:
            punctuation_stack.append(matching_punctuation[text[position]])
        position += 1
    if punctuation_stack:
        # Opening punctuations left without matching close-punctuations.
        return None
    # punctuations match.
    return text[start_position:position - 1]