wordfreq/scripts/gen_regex.py
2015-07-07 14:46:42 -04:00

57 lines
1.8 KiB
Python

import argparse
import unicodedata
import chardata
def _emoji_char_class():
"""
Build a regex for emoji substitution. First we create a regex character set
(like "[a-cv-z]") matching characters we consider emoji The final regex
matches one such character followed by any number of spaces and identical
characters.
"""
ranges = []
for i, c in enumerate(chardata.CHAR_CLASS_STRING):
if c == '3' and i >= 0x2600 and i != 0xfffd:
if ranges and i == ranges[-1][1] + 1:
ranges[-1][1] = i
else:
ranges.append([i, i])
return '[%s]' % ''.join(chr(a) + '-' + chr(b) for a, b in ranges)
def func_to_regex(accept):
"""
Converts a function that accepts a single unicode character into a regex.
Unassigned unicode characters are treated like their neighbors.
"""
ranges = []
start = None
has_accepted = False
for x in range(0x110000):
c = chr(x)
if accept(c):
has_accepted = True
if start is None:
start = None
elif unicodedata.category(c) == 'Cn':
if start is None:
start = c
elif start is not None:
if has_accepted:
ranges.append('-'.join([start, chr(x-1)]))
has_accepted = False
start = None
else:
if has_accepted and start is not None:
ranges.append('-'.join([start, chr(x-1)]))
return '[%s]' % ''.join(ranges)
if __name__ == '__main__':
import argparse
parser = argparse.ArgumentParser(description='Generate a regex matching a function')
parser.add_argument('acceptor', help='an python function that accepts a single char')
args = parser.parse_args()
print(func_to_regex(eval(args.acceptor)))