add helper and modifier helpers

[patricklx]

fixes #410

the documentation for them is not published yet. It should be there when 4.7 is published:
emberjs/ember.js@d75a0cb

[chriskrycho]

Thank you! One of us will review this week!

[chriskrycho]

@patricklx thanks again for opening this; mind fixing up the CI failures? I'll try to review tomorrow or Friday!

[dfreeman]

Thank you for opening this, @patricklx!

In addition to the things flagged in CI, I think these are going to need to be a bit more complex to capture what {{helper}} and {{modifier}} can do, which isn't just looking up global helpers/modifiers, but also pre-binding arguments to either a global {{helper "foo" 123 arg="hi"}} or to actual helper values {{helper this.someHelper 123 arg="hi"}}.

You can see an example of how this works with the {{component}} helper, which does the same thing: https://github.com/typed-ember/glint/blob/main/packages/environment-ember-loose/-private/intrinsics/component.d.ts

Is that something you've got the time/interest to take on? If so, great, and let us know if you need any additional guidance. If not, no worries—Chris or I should hopefully be able to get to it in the near future.

[boris-petrov]

I just noticed that these two:

<div {{(if true (modifier "on" "click" this.func))}}></div>
<div {{(if true (modifier "on")) "click" this.func}}></div>

Actually mean the same thing so Glint should somehow support them both. No idea how. 😄

[dfreeman]

Yep! Those two examples should fall out naturally and "just work" assuming we implement the currying semantics of those two helpers I mentioned above 🙂

[SergeAstapov]

Hi @patricklx! Would you be able to pick up the suggestion from @dfreeman how to overcome missing parts here?

[chriskrycho]

Actually, I believe @dfreeman is working on getting these done. From Discord:

I’m working on adding those (and hopefully slightly improving inference characteristics for {{component}}) for what should be the final 1.0 beta release

🎉