Throttle and debounce implemented in Go

throttledebounce.go

// This gist is a reminder to myself about the differences between throttling and debouncing, inspired by
// https://redd.one/blog/debounce-vs-throttle
//
// A runnable example is available here: https://play.golang.org/p/sADDu829fRa
package main

import (
	"fmt"
	"time"
)

func main() {
	f := func() { fmt.Println("Hello from throttled") }
	throttled := throttle(f, time.Second)
	callNTimesWithDelay(throttled, 10, 500*time.Millisecond)

	g := func() { fmt.Println("Hello from debounced") }
	debounced := debounce(g, 500*time.Millisecond)
	callNTimesWithDelay(debounced, 10, 100*time.Millisecond)

	// Wait to allow the debounce timer to tick
	<-time.After(time.Second)

	// Call again to see the effect of only calling a debounced function once.
	debounced()
	<-time.After(time.Second)
}

func throttle(f func(), d time.Duration) func() {
	shouldWait := false

	return func() {
		if !shouldWait {
			f()
			shouldWait = true

			go func() {
				<-time.After(d)
				shouldWait = false
			}()
		} else {
			fmt.Println("Throttled...")
		}
	}
}

func debounce(f func(), d time.Duration) func() {
	var t *time.Timer
	return func() {
		if t != nil && !t.Stop() {
			<-t.C
		}
		fmt.Println("Debounced...")
		t = time.AfterFunc(d, func() {
			f()
			t = nil
		})
	}
}

func callNTimesWithDelay(f func(), n int, delay time.Duration) {
	for i := 0; i < n; i++ {
		f()
		<-time.After(delay)
	}
}