1"""
2Parse link destination
3"""
4
5from ..common.utils import charCodeAt, unescapeAll
6
7
8class _Result:
9 __slots__ = ("ok", "pos", "str")
10
11 def __init__(self) -> None:
12 self.ok = False
13 self.pos = 0
14 self.str = ""
15
16
17def parseLinkDestination(string: str, pos: int, maximum: int) -> _Result:
18 start = pos
19 result = _Result()
20
21 if charCodeAt(string, pos) == 0x3C: # /* < */
22 pos += 1
23 while pos < maximum:
24 code = charCodeAt(string, pos)
25 if code == 0x0A: # /* \n */)
26 return result
27 if code == 0x3C: # / * < * /
28 return result
29 if code == 0x3E: # /* > */) {
30 result.pos = pos + 1
31 result.str = unescapeAll(string[start + 1 : pos])
32 result.ok = True
33 return result
34
35 if code == 0x5C and pos + 1 < maximum: # \
36 pos += 2
37 continue
38
39 pos += 1
40
41 # no closing '>'
42 return result
43
44 # this should be ... } else { ... branch
45
46 level = 0
47 while pos < maximum:
48 code = charCodeAt(string, pos)
49
50 if code is None or code == 0x20:
51 break
52
53 # ascii control characters
54 if code < 0x20 or code == 0x7F:
55 break
56
57 if code == 0x5C and pos + 1 < maximum:
58 if charCodeAt(string, pos + 1) == 0x20:
59 break
60 pos += 2
61 continue
62
63 if code == 0x28: # /* ( */)
64 level += 1
65 if level > 32:
66 return result
67
68 if code == 0x29: # /* ) */)
69 if level == 0:
70 break
71 level -= 1
72
73 pos += 1
74
75 if start == pos:
76 return result
77 if level != 0:
78 return result
79
80 result.str = unescapeAll(string[start:pos])
81 result.pos = pos
82 result.ok = True
83 return result