1set/gut

package ystring

import (
    "unicode/utf8"
)

// Length returns the number of runes in a given string.
func Length(s string) int {
    return utf8.RuneCountInString(s)
}

// Truncate returns first n runes of s.
func Truncate(s string, n int) string {
    switch {
    case n < 0:
        panic("ystring: negative Truncate length n")
    case n == 0:
        return s[0:0]
    case n >= len(s):
        return s
    }

    cnt := 0
    for idx := range s {
        if n <= cnt {
            return s[0:idx]
        }
        cnt++
    }
    return s
}