added

vendor/github.com/mattn/go-runewidth/runewidth.go

@@ -0,0 +1,241 @@
+package runewidth
+
+import (
+	"os"
+
+	"github.com/rivo/uniseg"
+)
+
+//go:generate go run script/generate.go
+
+var (
+	// EastAsianWidth will be set true if the current locale is CJK
+	EastAsianWidth 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
+}
+
+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
+}
+
+// NewCondition return new instance of Condition which is current locale.
+func NewCondition() *Condition {
+	return &Condition{
+		EastAsianWidth: EastAsianWidth,
+	}
+}
+
+// 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
+	}
+}
+
+// StringWidth return width as you can see
+func (c *Condition) StringWidth(s string) (width int) {
+	g := uniseg.NewGraphemes(s)
+	for g.Next() {
+		var chWidth int
+		for _, r := range g.Runes() {
+			chWidth = c.RuneWidth(r)
+			if chWidth > 0 {
+				break // Our best guess at this point is to use the width of the first non-zero-width rune.
+			}
+		}
+		width += chWidth
+	}
+	return
+}
+
+// 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
+	}
+	w -= c.StringWidth(tail)
+	var width int
+	pos := len(s)
+	g := uniseg.NewGraphemes(s)
+	for g.Next() {
+		var chWidth int
+		for _, r := range g.Runes() {
+			chWidth = c.RuneWidth(r)
+			if chWidth > 0 {
+				break // See StringWidth() for details.
+			}
+		}
+		if width+chWidth > w {
+			pos, _ = g.Positions()
+			break
+		}
+		width += chWidth
+	}
+	return s[:pos] + 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 := c.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)
+}