Calling Lisp functions from generated JS?

[aerique]

Aaaand, I'm back.

I can't figure out how to have a callback call a Lisp function. I want requestAnimationFrame to call a Lisp function (or rather a function I have defined in main.lisp which is compiled to main.js).

So I have this function

(defun printdelta (delta)
  (#j:console.log (format nil "delta=~S" delta)))

And I want to call it with (#j:window.requestAnimationFrame #'printdelta). Now I've searched online and tried all kinds of different things for #'printdelta: "printdelta", 'printdelta, (lambda (delta) (funcall 'printdelta delta)), etc. etc.

But I cannot figure it out.

[hemml]

You can use jscl.evaluateString("(printdelta "+delta+")") but this approach is rather slow, because the code will be recompiled for every call.
You can obtain and use a reference to compiled function:

let printdelta=jscl.evaluateString("#'printdelta")
printdelta(delta)

[aerique]

But how to do this from Lisp?

[hemml]

Oh, sorry, I didn't read the message carefully)
The following code works:

((jscl::oget (jscl::%js-vref "window") "requestAnimationFrame") #'printdelta)

[aerique]

Hm, I think I still have an issue with my environment (see my other discussion message).

Even doing (printdelta 1) from Lisp gets me the following error (actually the same error as using your statement above):

Uncaught TypeError: internals.symbolValue(...)[internals.xstring(...)] is not a function
    fvalue http://localhost:8000/main.js:23
    JSCL_USER_PRINTDELTA http://localhost:8000/main.js:24
    <anonymous> http://localhost:8000/main.js:71
    <anonymous> http://localhost:8000/main.js:72
    <anonymous> http://localhost:8000/main.js:73

(I'll investigate it later today.)

[aerique]

As I wrote in my reply to @davazp, it was the #j:console.log typo 😅

So, thanks!

[davazp]

Your example works for me.

Just that your function uses a wrong syntax #j:console.log, it should be #j:console:log

https://jscl-project.github.io/

(defun printdelta (delta)
  (#j:console:log (format nil "delta=~S" delta)))

(#j:requestAnimationFrame #'printdelta)

Note that the REPL reads 1 form at at time. So you can't just copy-paste both. It'd be nice to fix this.

[davazp]

It'd also be really nice to have a playground that takes code in the URL so we can share snippets and run it against https://jscl-project.github.io/ (which is the version in master)

[aerique]

Agh, it was indeed the #j:console.log typo. (In ClojureScript it's js/console.log.)

It works now, thanks guys!