go: 格式化字符串，类似于python

package helper

import (
    "fmt"
    "strconv"
    "strings"
)

func Fmt(format string, args ...interface{}) string {
    argsWithKey := []string{}
    for i, v := range args {
        argsWithKey = append(argsWithKey, "{"+strconv.Itoa(i)+"}")
        argsWithKey = append(argsWithKey, fmt.Sprintf("%v", v))
    }

    format = getFormat(format)
    r := strings.NewReplacer(argsWithKey...)
    return r.Replace(format)
}

func getFormat(format string) string {
    // 先用 {{  }}切分成数组
    arr := []string{}

    start := 0
    i := 0
    for i < len(format) {
        // 找到一个 {{
        if format[i] == '{' && i+1 < len(format) && format[i+1] == '{' {
            arr = append(arr, format[start:i])
            arr = append(arr, "{{")
            i += 2
            start = i
        }
        // 找到一个 }}
        if format[i] == '}' && i+1 < len(format) && format[i+1] == '}' {
            arr = append(arr, format[start:i])
            arr = append(arr, "}}")
            i += 2
            start = i
        }
        i++
    }
    if start < len(format) {
        arr = append(arr, format[start:])
    }

    // 此时，只剩下了 {}，往里面填数字，{} {} -> {0} {1}
    quotoNum := 0
    for arrIndex, v := range arr {
        tempStr := v
        for true {
            pos := strings.Index(tempStr, "{}")
            if pos == -1 {
                break
            }
            tempStr = tempStr[:pos] + "{" + strconv.Itoa(quotoNum) + "}" +
                tempStr[pos+2:]
            quotoNum++
        }
        arr[arrIndex] = tempStr
    }

    result := ""
    for _, v := range arr {
        v = strings.Replace(v, "{{", "{", -1)
        v = strings.Replace(v, "}}", "}", -1)
        result += v
    }
    return result
}

logger.Infoln(helper.Fmt("{0}ha{1}{{{1}", "hello", "world"))
    logger.Infoln(helper.Fmt("{}ha{}{{{}", "hello", "world", "haha"))
    logger.Infoln(helper.Fmt("{{}}{}", "hello"))
    logger.Infoln(helper.Fmt("{{}}{}{}", "hello", "world"))
    logger.Infoln(helper.Fmt("{} is a big.{}", "大猪", "ha"))