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
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
|
// A convenient and efficient way to index strings by `Unicode` code point (`rune`) rather than byte.
package utf8string
import "core:unicode/utf8"
import "base:runtime"
import "base:builtin"
String :: struct {
contents: string,
rune_count: int,
// cached information
non_ascii: int, // index to non-ascii code points
width: int, // 0 if ascii
byte_pos: int,
rune_pos: int,
}
@(private)
_len :: builtin.len // helper procedure
init :: proc(s: ^String, contents: string) -> ^String {
s.contents = contents
s.byte_pos = 0
s.rune_pos = 0
for i in 0..<_len(contents) {
if contents[i] >= utf8.RUNE_SELF {
s.rune_count = utf8.rune_count_in_string(contents)
_, s.width = utf8.decode_rune_in_string(contents)
s.non_ascii = i
return s
}
}
s.rune_count = _len(contents)
s.width = 0
s.non_ascii = _len(contents)
return s
}
to_string :: proc(s: ^String) -> string {
return s.contents
}
len :: proc(s: ^String) -> int {
return s.rune_count
}
is_ascii :: proc(s: ^String) -> bool {
return s.width == 0
}
at :: proc(s: ^String, i: int, loc := #caller_location) -> (r: rune) {
runtime.bounds_check_error_loc(loc, i, s.rune_count)
if i < s.non_ascii {
return rune(s.contents[i])
}
switch i {
case 0:
r, s.width = utf8.decode_rune_in_string(s.contents)
s.rune_pos = 0
s.byte_pos = 0
return
case s.rune_count-1:
r, s.width = utf8.decode_last_rune(s.contents)
s.rune_pos = i
s.byte_pos = _len(s.contents) - s.width
return
case s.rune_pos-1:
r, s.width = utf8.decode_rune_in_string(s.contents[0:s.byte_pos])
s.rune_pos = i
s.byte_pos -= s.width
return
case s.rune_pos+1:
s.rune_pos = i
s.byte_pos += s.width
fallthrough
case s.rune_pos:
r, s.width = utf8.decode_rune_in_string(s.contents[s.byte_pos:])
return
}
// Linear scan
scan_forward := true
if i < s.rune_pos {
if i < (s.rune_pos-s.non_ascii)/2 {
s.byte_pos, s.rune_pos = s.non_ascii, s.non_ascii
} else {
scan_forward = false
}
} else if i-s.rune_pos < (s.rune_count-s.rune_pos)/2 {
// scan_forward = true
} else {
s.byte_pos, s.rune_pos = _len(s.contents), s.rune_count
scan_forward = false
}
if scan_forward {
for {
r, s.width = utf8.decode_rune_in_string(s.contents[s.byte_pos:])
if s.rune_pos == i {
return
}
s.rune_pos += 1
s.byte_pos += s.width
}
} else {
for {
r, s.width = utf8.decode_last_rune_in_string(s.contents[:s.byte_pos])
s.rune_pos -= 1
s.byte_pos -= s.width
if s.rune_pos == i {
return
}
}
}
}
slice :: proc(s: ^String, i, j: int, loc := #caller_location) -> string {
runtime.slice_expr_error_lo_hi_loc(loc, i, j, s.rune_count)
if j < s.non_ascii {
return s.contents[i:j]
}
if i == j {
return ""
}
lo, hi: int
if i < s.non_ascii {
lo = i
} else if i == s.rune_count {
lo = _len(s.contents)
} else {
at(s, i, loc)
lo = s.byte_pos
}
if j == s.rune_count {
hi = _len(s.contents)
} else {
at(s, j, loc)
hi = s.byte_pos
}
return s.contents[lo:hi]
}
|
