trasform a vim wildignore value into a list of python regexes

wildignore_parser.py

import os, sys
def OnWindows():
  return sys.platform == 'win32'
def Parser( wildignore ):
  regex_list = []
  skip_next = False
  saw_backslash = False
  for pattern in wildignore.split( ',' ):
    regex = ''
    for i, c in enumerate( pattern ):

      if skip_next:
        skip_next = False
        continue

      if saw_backslash:
        saw_backslash = False
        # If literal character is special we need to escape it
        if c == '*' or c == '?' or c == '[':
          regex += '\\'
        regex += c
        continue

      # wildignore doesn't treat \ as an escape character on Windows
      if c == '\\' and not OnWindows():
        saw_backslash = True
        continue

      if c == '*':
        if i + 1 < len( pattern ) and pattern[ i + 1 ] == '*':
          # ** found
          regex += '.*'
          skip_next = True
        else:
          # * found
          regex += '[^' + os.path.sep
          if os.path.altsep:
            regex += os.path.altsep
          regex += ']'
        continue

      if c == '?':
        regex += '.'
        continue

      regex += c

    regex_list.append( regex )
  return regex_list


if __name__ == '__main__':
  print( Parser( '\\asd\\*asd,a*s\\?*,\\[asd]*?**' ) )