Files
2023-02-12 23:09:20 +08:00

102 lines
2.5 KiB
Go

// Package strutil provides various utilities for manipulating strings
package strutil
import (
"bytes"
"regexp"
"github.com/mattn/go-runewidth"
)
const ansi = "[\u001B\u009B][[\\]()#;?]*(?:(?:(?:[a-zA-Z\\d]*(?:;[a-zA-Z\\d]*)*)?\u0007)|(?:(?:\\d{1,4}(?:;\\d{0,4})*)?[\\dA-PRZcf-ntqry=><~]))"
var re = regexp.MustCompile(ansi)
// PadRight returns a new string of a specified length in which the end of the current string is padded with spaces or with a specified Unicode character.
func PadRight(str string, length int, pad byte) string {
slen := StringWidth(str)
if slen >= length {
return str
}
buf := bytes.NewBufferString(str)
for i := 0; i < length-slen; i++ {
buf.WriteByte(pad)
}
return buf.String()
}
// PadLeft returns a new string of a specified length in which the beginning of the current string is padded with spaces or with a specified Unicode character.
func PadLeft(str string, length int, pad byte) string {
slen := StringWidth(str)
if slen >= length {
return str
}
var buf bytes.Buffer
for i := 0; i < length-slen; i++ {
buf.WriteByte(pad)
}
buf.WriteString(str)
return buf.String()
}
// Resize resizes the string with the given length. It ellipses with '...' when the string's length exceeds
// the desired length or pads spaces to the right of the string when length is smaller than desired
func Resize(s string, length uint, rightAlign bool) string {
slen := StringWidth(s)
n := int(length)
if slen == n {
return s
}
// Pads only when length of the string smaller than len needed
if rightAlign {
s = PadLeft(s, n, ' ')
} else {
s = PadRight(s, n, ' ')
}
if slen > n {
rs := []rune(s)
var buf bytes.Buffer
w := 0
for _, r := range rs {
buf.WriteRune(r)
rw := RuneWidth(r)
if w+rw >= n-3 {
break
}
w += rw
}
buf.WriteString("...")
s = buf.String()
}
return s
}
// Join joins the list of the string with the delim provided.
// Returns an empty string for empty list
func Join(list []string, delim string) string {
if len(list) == 0 {
return ""
}
var buf bytes.Buffer
for i := 0; i < len(list)-1; i++ {
buf.WriteString(list[i] + delim)
}
buf.WriteString(list[len(list)-1])
return buf.String()
}
// Strip strips the string of all colors
func Strip(s string) string {
return re.ReplaceAllString(s, "")
}
// StringWidth returns the actual width of the string without colors
func StringWidth(s string) int {
return runewidth.StringWidth(Strip(s))
}
// RuneWidth returns the actual width of the rune
func RuneWidth(s rune) int {
return runewidth.RuneWidth(s)
}