Question: pool about sorg HOT 4 CLOSED

This might be a slightly suboptimal answer because I haven't thought about it in a while, but since we're storing an error on Task already anyway, it probably also makes sense to just put the result there as well:

type Task struct {
	Err error
	Result interface{}
	f func() (interface{}, error)
}

func (t *Task) Run(wg *sync.WaitGroup) {
	t.Result, t.Err = t.f()
	wg.Done()
}

It's not great that you have to fall back to interface{} for this though ... it might be worthwhile seeing if you could build some task-specific shims on top of Task whose only job is to transform interface{} back to something more material.

from sorg.

Thanks @brandur so something like

	tasks := []*pool.Task{
		pool.NewTask(func() (interface{}, error) { return nil, nil }),
		pool.NewTask(func() (interface{}, error) { return true, nil }),
		pool.NewTask(func() (interface{}, error) { return 20, nil }),
		pool.NewTask(func() (interface{}, error) { return time.Now(), nil }),
	}

And if the Task has to be parameterised assume the signature would need to change to use a variadic interface?

func(a ...interface{}) (interface{}, error)

from sorg.

Thanks @brandur so something like

No worries. And yes — that looks right.

And if the Task has to be parameterised assume the signature would need to change to use a variadic interface?

It's mostly up to your preference again. You could also add your arguments into Task again:

type Task struct {
	Args []interface{} 
	Err error
	Result interface{}
	f func() (interface{}, error)
}

Alternatively, remember that those func() are closures and can capture variables from their surrounding environment. You could also inject data that way:

arg1 := ...
arg2 := ...
pool.NewTask(func() (interface{}, error) {
	fmt.Printf("%v %v\n", arg1, arg2)
	return nil, nil
}),

from sorg.

Thanks, new to go, just finished reading up on closures and scope, your proposal makes perfect sense. Appreciate the response.

Damian.

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