Unescape code start

def unescape_code_start(source, ext, language='python'):
    """Unescape code start"""
    parser = StringParser(language)
    for pos, line in enumerate(source):
        if not parser.is_quoted() and is_escaped_code_start(line, ext):
            unescaped = unesc(line, language)
            # don't remove comment char if we break the code start...
            if is_escaped_code_start(unescaped, ext):
                source[pos] = unescaped
        parser.read_line(line)
    return source