string.go

package gutil

import "strings"

// CamelString xx_yy to XxYy)
func CamelString(s string) string {
	data := make([]byte, 0, len(s))
	j := false
	k := false
	num := len(s) - 1
	for i := 0; i <= num; i++ {
		d := s[i]
		if k == false && d >= 'A' && d <= 'Z' {
			k = true
		}
		if d >= 'a' && d <= 'z' && (j || k == false) {
			d = d - 32
			j = false
			k = true
		}
		if k && d == '_' && num > i && s[i+1] >= 'a' && s[i+1] <= 'z' {
			j = true
			continue
		}
		data = append(data, d)
	}
	return BytesToString(data[:])
}

// SnakeString XxYy to xx_yy
func SnakeString(s string) string {
	data := make([]byte, 0, len(s)*2)
	j := false
	for _, d := range StringToBytes(s) {
		if d >= 'A' && d <= 'Z' {
			if j {
				data = append(data, '_')
				j = false
			}
		} else if d != '_' {
			j = true
		}
		data = append(data, d)
	}
	return strings.ToLower(BytesToString(data))
}