subsonic-tui/vendor/github.com/rivo/uniseg/width.go

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package uniseg
// EastAsianAmbiguousWidth specifies the monospace width for East Asian
// characters classified as Ambiguous. The default is 1 but some rare fonts
// render them with a width of 2.
var EastAsianAmbiguousWidth = 1
// runeWidth returns the monospace width for the given rune. The provided
// grapheme property is a value mapped by the [graphemeCodePoints] table.
//
// Every rune has a width of 1, except for runes with the following properties
// (evaluated in this order):
//
// - Control, CR, LF, Extend, ZWJ: Width of 0
// - \u2e3a, TWO-EM DASH: Width of 3
// - \u2e3b, THREE-EM DASH: Width of 4
// - East-Asian width Fullwidth and Wide: Width of 2 (Ambiguous and Neutral
// have a width of 1)
// - Regional Indicator: Width of 2
// - Extended Pictographic: Width of 2, unless Emoji Presentation is "No".
func runeWidth(r rune, graphemeProperty int) int {
switch graphemeProperty {
case prControl, prCR, prLF, prExtend, prZWJ:
return 0
case prRegionalIndicator:
return 2
case prExtendedPictographic:
if property(emojiPresentation, r) == prEmojiPresentation {
return 2
}
return 1
}
switch r {
case 0x2e3a:
return 3
case 0x2e3b:
return 4
}
switch propertyEastAsianWidth(r) {
case prW, prF:
return 2
case prA:
return EastAsianAmbiguousWidth
}
return 1
}
// StringWidth returns the monospace width for the given string, that is, the
// number of same-size cells to be occupied by the string.
func StringWidth(s string) (width int) {
state := -1
for len(s) > 0 {
var w int
_, s, w, state = FirstGraphemeClusterInString(s, state)
width += w
}
return
}