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
|
package liner
import "unicode"
// These character classes are mostly zero width (when combined).
// A few might not be, depending on the user's font. Fixing this
// is non-trivial, given that some terminals don't support
// ANSI DSR/CPR
var zeroWidth = []*unicode.RangeTable{
unicode.Mn,
unicode.Me,
unicode.Cc,
unicode.Cf,
}
var doubleWidth = []*unicode.RangeTable{
unicode.Han,
unicode.Hangul,
unicode.Hiragana,
unicode.Katakana,
}
// countGlyphs considers zero-width characters to be zero glyphs wide,
// and members of Chinese, Japanese, and Korean scripts to be 2 glyphs wide.
func countGlyphs(s []rune) int {
n := 0
for _, r := range s {
switch {
case unicode.IsOneOf(zeroWidth, r):
case unicode.IsOneOf(doubleWidth, r):
n += 2
default:
n++
}
}
return n
}
func countMultiLineGlyphs(s []rune, columns int, start int) int {
n := start
for _, r := range s {
switch {
case unicode.IsOneOf(zeroWidth, r):
case unicode.IsOneOf(doubleWidth, r):
n += 2
// no room for a 2-glyphs-wide char in the ending
// so skip a column and display it at the beginning
if n%columns == 1 {
n++
}
default:
n++
}
}
return n
}
func getPrefixGlyphs(s []rune, num int) []rune {
p := 0
for n := 0; n < num && p < len(s); p++ {
if !unicode.IsOneOf(zeroWidth, s[p]) {
n++
}
}
for p < len(s) && unicode.IsOneOf(zeroWidth, s[p]) {
p++
}
return s[:p]
}
func getSuffixGlyphs(s []rune, num int) []rune {
p := len(s)
for n := 0; n < num && p > 0; p-- {
if !unicode.IsOneOf(zeroWidth, s[p-1]) {
n++
}
}
return s[p:]
}
|
