codekingpro/portable-devtools

1"""2    pygments.regexopt3    ~~~~~~~~~~~~~~~~~4 5    An algorithm that generates optimized regexes for matching long lists of6    literal strings.7 8    :copyright: Copyright 2006-2024 by the Pygments team, see AUTHORS.9    :license: BSD, see LICENSE for details.10"""11 12import re13from re import escape14from os.path import commonprefix15from itertools import groupby16from operator import itemgetter17 18CS_ESCAPE = re.compile(r'[\[\^\\\-\]]')19FIRST_ELEMENT = itemgetter(0)20 21 22def make_charset(letters):23    return '[' + CS_ESCAPE.sub(lambda m: '\\' + m.group(), ''.join(letters)) + ']'24 25 26def regex_opt_inner(strings, open_paren):27    """Return a regex that matches any string in the sorted list of strings."""28    close_paren = open_paren and ')' or ''29    # print strings, repr(open_paren)30    if not strings:31        # print '-> nothing left'32        return ''33    first = strings[0]34    if len(strings) == 1:35        # print '-> only 1 string'36        return open_paren + escape(first) + close_paren37    if not first:38        # print '-> first string empty'39        return open_paren + regex_opt_inner(strings[1:], '(?:') \40            + '?' + close_paren41    if len(first) == 1:42        # multiple one-char strings? make a charset43        oneletter = []44        rest = []45        for s in strings:46            if len(s) == 1:47                oneletter.append(s)48            else:49                rest.append(s)50        if len(oneletter) > 1:  # do we have more than one oneletter string?51            if rest:52                # print '-> 1-character + rest'53                return open_paren + regex_opt_inner(rest, '') + '|' \54                    + make_charset(oneletter) + close_paren55            # print '-> only 1-character'56            return open_paren + make_charset(oneletter) + close_paren57    prefix = commonprefix(strings)58    if prefix:59        plen = len(prefix)60        # we have a prefix for all strings61        # print '-> prefix:', prefix62        return open_paren + escape(prefix) \63            + regex_opt_inner([s[plen:] for s in strings], '(?:') \64            + close_paren65    # is there a suffix?66    strings_rev = [s[::-1] for s in strings]67    suffix = commonprefix(strings_rev)68    if suffix:69        slen = len(suffix)70        # print '-> suffix:', suffix[::-1]71        return open_paren \72            + regex_opt_inner(sorted(s[:-slen] for s in strings), '(?:') \73            + escape(suffix[::-1]) + close_paren74    # recurse on common 1-string prefixes75    # print '-> last resort'76    return open_paren + \77        '|'.join(regex_opt_inner(list(group[1]), '')78                 for group in groupby(strings, lambda s: s[0] == first[0])) \79        + close_paren80 81 82def regex_opt(strings, prefix='', suffix=''):83    """Return a compiled regex that matches any string in the given list.84 85    The strings to match must be literal strings, not regexes.  They will be86    regex-escaped.87 88    *prefix* and *suffix* are pre- and appended to the final regex.89    """90    strings = sorted(strings)91    return prefix + regex_opt_inner(strings, '(') + suffix92