diff options
Diffstat (limited to 'vendor/github.com/mattn/go-runewidth/runewidth.go')
| -rw-r--r-- | vendor/github.com/mattn/go-runewidth/runewidth.go | 257 |
1 files changed, 257 insertions, 0 deletions
diff --git a/vendor/github.com/mattn/go-runewidth/runewidth.go b/vendor/github.com/mattn/go-runewidth/runewidth.go new file mode 100644 index 000000000..19f8e0449 --- /dev/null +++ b/vendor/github.com/mattn/go-runewidth/runewidth.go @@ -0,0 +1,257 @@ +package runewidth + +import ( + "os" +) + +//go:generate go run script/generate.go + +var ( + // EastAsianWidth will be set true if the current locale is CJK + EastAsianWidth bool + + // ZeroWidthJoiner is flag to set to use UTR#51 ZWJ + ZeroWidthJoiner bool + + // DefaultCondition is a condition in current locale + DefaultCondition = &Condition{} +) + +func init() { + handleEnv() +} + +func handleEnv() { + env := os.Getenv("RUNEWIDTH_EASTASIAN") + if env == "" { + EastAsianWidth = IsEastAsian() + } else { + EastAsianWidth = env == "1" + } + // update DefaultCondition + DefaultCondition.EastAsianWidth = EastAsianWidth + DefaultCondition.ZeroWidthJoiner = ZeroWidthJoiner +} + +type interval struct { + first rune + last rune +} + +type table []interval + +func inTables(r rune, ts ...table) bool { + for _, t := range ts { + if inTable(r, t) { + return true + } + } + return false +} + +func inTable(r rune, t table) bool { + if r < t[0].first { + return false + } + + bot := 0 + top := len(t) - 1 + for top >= bot { + mid := (bot + top) >> 1 + + switch { + case t[mid].last < r: + bot = mid + 1 + case t[mid].first > r: + top = mid - 1 + default: + return true + } + } + + return false +} + +var private = table{ + {0x00E000, 0x00F8FF}, {0x0F0000, 0x0FFFFD}, {0x100000, 0x10FFFD}, +} + +var nonprint = table{ + {0x0000, 0x001F}, {0x007F, 0x009F}, {0x00AD, 0x00AD}, + {0x070F, 0x070F}, {0x180B, 0x180E}, {0x200B, 0x200F}, + {0x2028, 0x202E}, {0x206A, 0x206F}, {0xD800, 0xDFFF}, + {0xFEFF, 0xFEFF}, {0xFFF9, 0xFFFB}, {0xFFFE, 0xFFFF}, +} + +// Condition have flag EastAsianWidth whether the current locale is CJK or not. +type Condition struct { + EastAsianWidth bool + ZeroWidthJoiner bool +} + +// NewCondition return new instance of Condition which is current locale. +func NewCondition() *Condition { + return &Condition{ + EastAsianWidth: EastAsianWidth, + ZeroWidthJoiner: ZeroWidthJoiner, + } +} + +// RuneWidth returns the number of cells in r. +// See http://www.unicode.org/reports/tr11/ +func (c *Condition) RuneWidth(r rune) int { + switch { + case r < 0 || r > 0x10FFFF || inTables(r, nonprint, combining, notassigned): + return 0 + case (c.EastAsianWidth && IsAmbiguousWidth(r)) || inTables(r, doublewidth): + return 2 + default: + return 1 + } +} + +func (c *Condition) stringWidth(s string) (width int) { + for _, r := range []rune(s) { + width += c.RuneWidth(r) + } + return width +} + +func (c *Condition) stringWidthZeroJoiner(s string) (width int) { + r1, r2 := rune(0), rune(0) + for _, r := range []rune(s) { + if r == 0xFE0E || r == 0xFE0F { + continue + } + w := c.RuneWidth(r) + if r2 == 0x200D && inTables(r, emoji) && inTables(r1, emoji) { + if width < w { + width = w + } + } else { + width += w + } + r1, r2 = r2, r + } + return width +} + +// StringWidth return width as you can see +func (c *Condition) StringWidth(s string) (width int) { + if c.ZeroWidthJoiner { + return c.stringWidthZeroJoiner(s) + } + return c.stringWidth(s) +} + +// Truncate return string truncated with w cells +func (c *Condition) Truncate(s string, w int, tail string) string { + if c.StringWidth(s) <= w { + return s + } + r := []rune(s) + tw := c.StringWidth(tail) + w -= tw + width := 0 + i := 0 + for ; i < len(r); i++ { + cw := c.RuneWidth(r[i]) + if width+cw > w { + break + } + width += cw + } + return string(r[0:i]) + tail +} + +// Wrap return string wrapped with w cells +func (c *Condition) Wrap(s string, w int) string { + width := 0 + out := "" + for _, r := range []rune(s) { + cw := RuneWidth(r) + if r == '\n' { + out += string(r) + width = 0 + continue + } else if width+cw > w { + out += "\n" + width = 0 + out += string(r) + width += cw + continue + } + out += string(r) + width += cw + } + return out +} + +// FillLeft return string filled in left by spaces in w cells +func (c *Condition) FillLeft(s string, w int) string { + width := c.StringWidth(s) + count := w - width + if count > 0 { + b := make([]byte, count) + for i := range b { + b[i] = ' ' + } + return string(b) + s + } + return s +} + +// FillRight return string filled in left by spaces in w cells +func (c *Condition) FillRight(s string, w int) string { + width := c.StringWidth(s) + count := w - width + if count > 0 { + b := make([]byte, count) + for i := range b { + b[i] = ' ' + } + return s + string(b) + } + return s +} + +// RuneWidth returns the number of cells in r. +// See http://www.unicode.org/reports/tr11/ +func RuneWidth(r rune) int { + return DefaultCondition.RuneWidth(r) +} + +// IsAmbiguousWidth returns whether is ambiguous width or not. +func IsAmbiguousWidth(r rune) bool { + return inTables(r, private, ambiguous) +} + +// IsNeutralWidth returns whether is neutral width or not. +func IsNeutralWidth(r rune) bool { + return inTable(r, neutral) +} + +// StringWidth return width as you can see +func StringWidth(s string) (width int) { + return DefaultCondition.StringWidth(s) +} + +// Truncate return string truncated with w cells +func Truncate(s string, w int, tail string) string { + return DefaultCondition.Truncate(s, w, tail) +} + +// Wrap return string wrapped with w cells +func Wrap(s string, w int) string { + return DefaultCondition.Wrap(s, w) +} + +// FillLeft return string filled in left by spaces in w cells +func FillLeft(s string, w int) string { + return DefaultCondition.FillLeft(s, w) +} + +// FillRight return string filled in left by spaces in w cells +func FillRight(s string, w int) string { + return DefaultCondition.FillRight(s, w) +} |