VictoriaMetrics/vendor/github.com/mattn/go-runewidth/runewidth.go
Aliaksandr Valialkin d5c180e680 app/vmctl: move vmctl code from github.com/VictoriaMetrics/vmctl
It is better developing vmctl tool in VictoriaMetrics repository, so it could be released
together with the rest of vmutils tools such as vmalert, vmagent, vmbackup, vmrestore and vmauth.
2021-02-01 01:10:20 +02:00

259 lines
5.2 KiB
Go

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 {
// func (t table) IncludesRune(r rune) 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)
}