async.go

package goneric

import "sync"

// Async runs a function in goroutine and returns pipe with result
func Async[T1 any](f func() T1) chan T1 {
	out := make(chan T1, 1)
	go func() {
		out <- f()
	}()
	return out
}

// AsyncV runs a number of functions in goroutine and returns pipe with result then closes after goroutines finish
// order is not guaranteed
func AsyncV[T1 any](funcList ...func() T1) chan T1 {
	out := make(chan T1, 1)
	wg := sync.WaitGroup{}
	for _, f := range funcList {
		wg.Add(1)
		go func(f func() T1) {
			out <- f()
			wg.Done()
		}(f)
	}
	go func() {
		wg.Wait()
		close(out)
	}()
	return out
}

// AsyncVUnpanic runs a number of functions in goroutine and returns pipe with result then closes after goroutines finish
// order is not guaranteed
// panics are suppressed
func AsyncVUnpanic[T1 any](funcList ...func() T1) chan T1 {
	out := make(chan T1, 1)
	wg := sync.WaitGroup{}
	for _, f := range funcList {
		wg.Add(1)
		go func(f func() T1) {
			defer func() {
				wg.Done()
				recover()
			}()
			out <- f()
		}(f)
	}
	go func() {
		wg.Wait()
		close(out)
	}()
	return out
}

// AsyncPipe runs a function in goroutine from input channel and returns pipe with result
func AsyncPipe[T1, T2 any](in chan T1, f func(T1) T2) chan T2 {
	out := make(chan T2, 1)
	go func() {
		out <- f(<-in)
	}()
	return out
}

// AsyncOut takes value and feeds it to function returning asynchronously to channel
func AsyncOut[T1, T2 any](in chan T1, f func(T1) T2, out chan T2) {
	go func() {
		out <- f(<-in)
	}()
}

// AsyncIn turns value into channel with value
func AsyncIn[T1 any](in T1) (out chan T1) {
	out = make(chan T1, 1)
	out <- in
	return out
}