一个激励人心的例子:
实施各种调度“策略”,对“作业”列表进行排序。
type Job struct {
weight int
length int
}
// Given a slice of Jobs, re-order them.
type Strategy func([]Job) []Job
func Schedule(jobs []Job, strat Strategy) []Job {
return strat(jobs)
}
一种非常简单的策略是首先执行最短的作业(不考虑其权重/优先级)。
func MinCompletionTimes(job []Job) []Job {
// Hmm...
}
嗯,这种策略只不过是对job.length进行排序,因此让我们使用sort包。定义一个自定义类型,并实现sort.Interface ...
type JobSlice []Job // Should probably be called MinCompletionTimesJobSlice
func (js JobSlice) Len() {
return len(js)
}
func (js JobSlice) Less(i, j int) bool {
return js[i].length < js[j].length
}
func (js JobSlice) Swap(i, j int) {
js[i], js[j] = js[j], js[i]
}
好了,现在回到我们的简单策略...
func MinCompletionTimes(jobs []Job) []Job {
sort.Sort([]JobSlice(jobs)) // cannot convert jobs (type []Job) to type []JobSlice
return jobs
}
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