diff options
Diffstat (limited to 'vendor/github.com/rivo/uniseg/width.go')
-rw-r--r-- | vendor/github.com/rivo/uniseg/width.go | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/vendor/github.com/rivo/uniseg/width.go b/vendor/github.com/rivo/uniseg/width.go new file mode 100644 index 000000000..975a9f134 --- /dev/null +++ b/vendor/github.com/rivo/uniseg/width.go @@ -0,0 +1,61 @@ +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 +} |