Is there any method like `most.defer()` and `most.create()`?

I did not find most.defer() and most.create() in the API docs.

I need to defer a function call until it is subscribed.

most.defer(() => {
  result = getResult();
  return most.of(result);
})

How do I do to achieve my goal?

[briancavalier]

if the function f passed to the continueWith() only be called when subscribed

Yep, that’s correct. Closing since I believe this answers the original question.

Cheers!

[xareelee]

Can you help me understand the use case for a function like defer?

// without `defer`
function foo(options) {
  // has side-effect or inner dependency; 
  // would be triggered immediately (before the returned stream is subscribed)
  const settings = setup_settings(options);
  return most.of(settings);
}

// with `defer`
// we could wrap the whole implementation in the `defer`
function foo(options) {
  // defer the execution until subscribed
  return defer(() => {
    // only be triggered when the this stream is subscribed.
    const settings = setup_settings(options);
    return most.of(settings);
  });
}

Using defer to keep the impure function to be called only when it is subscribed. It’s important if the timing matters.

import { empty, continueWith, just } from 'most'

// Let's make our own defer() function
const defer = f => continueWith(f, empty())

// Use it
defer(() => just(getResult()))

I did not try this, but it seems OK if the function f passed to the continueWith() only be called when subscribed. Thanks for your help.