1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55r"""
Generate a regex character class representing the input.
cat a list of Unicode codepoints, one on each line in U+XXXX format. Unicode
literals will be in Python-style notation (\uXXXX, \UXXXXXXXX).
"""
import sys
is_javascript = 'js' in sys.argv
def _is_surrogate(codepoint):
return 0xd800 <= codepoint and codepoint <= 0xdfff
ranges = []
for line in sys.stdin:
_, hx = line.strip().split(maxsplit=1)[0].split('+')
n = int(hx, base=16)
if is_javascript and _is_surrogate(n):
# Including surrogates gives false matches with JavaScript. A minimal
# case is:
#
# /^[\udba1-\udbfe\udca1]$/u.test('\udc00') => true
#
# You would expect false, but \udbfe\udca1 is interpreted as \u{10f8a1}
# so a much greater range is mistakenly covered.
continue
start, end = ranges[-1] if ranges else (None, None)
if n - 1 == end:
ranges[-1] = (start, n)
else:
ranges.append((n, n))
regex_ranges = []
# astral?
templates = ({True: r'\u{%x}', False: r'\u%04x'} if is_javascript
else {True: r'\U%08x', False: r'\u%04x'})
for r in ranges:
is_astral = any(n > 0xffff for n in r)
tmpl = templates[is_astral]
is_range = r[0] != r[1]
if is_range:
regex = '-'.join([tmpl % part for part in r])
else:
regex = tmpl % r[0]
regex_ranges.append(regex)
print('[%s]' % ''.join(regex_ranges))