最简单的方式实现 Golang的级别日志

package lo

import (
    "log"
    "os"
)

const (
    TRACE int = iota
    DEBUG
    INFO
    WARN
    ERROR
    FATAL
)

type LevelLogger struct {
    level  int
    logger *log.Logger
}

var l *LevelLogger

func init() {
    l = &LevelLogger{
        level:  TRACE,
        logger: log.New(os.Stdout, "", 0),
    }
}

func SetLevel(level int) {
    l.level = level
}
func SetLogger(logger *log.Logger) {
    l.logger = logger
}

func Trace(v ...any) {
    if TRACE >= l.level {
        l.logger.Println("[TRACE]", v)
    }
}
func Debug(v ...any) {
    if DEBUG >= l.level {
        l.logger.Println("[DEBUG]", v)
    }
}
func Info(v ...any) {
    if INFO >= l.level {
        l.logger.Println("[INFO]", v)
    }
}
func Warn(v ...any) {
    if WARN >= l.level {
        l.logger.Println("[WARN]", v)
    }
}
func Error(v ...any) {
    if ERROR >= l.level {
        l.logger.Println("[ERROR]", v)
    }
}
func Fatal(v ...any) {
    if FATAL >= l.level {
        l.logger.Fatalln("[FATAL]", v)
    }
}

package main

import (
    "awesomeProject1/lo"
)

func main() {
    lo.SetLevel(lo.FATAL)
    lo.Trace("the is Trace")
    lo.Debug("the is Debug")
    lo.Info("the is Info")
    lo.Warn("the is Warn")
    lo.Error("the is Error")
    lo.Fatal("the is Fatal")
}