Get number of slots in variadic input

[cymplecy]

Very clever solution

I do think it could be made a lot simpler if we stuck to the Snap! block design restriction mentioned by Jens

10.0 looks amazing

but we did have the rule that a block should only have at most one variadic input and that it should be the last one, because when used inside call _ with inputs and collapsed it gets assigned all the arguments.

Then these two pieces of information would let us reconstruct the number of slots

1st one lets us know total number of slots
2nd one lets us identify which is static and then we can work out number of slots in the variadic one

My problem with your solution is that the only time I've used metaprograming is inside my Snap! -> OpenSCAD project

And since that uses codification - your solution wouldn't work

But I do like how you've made your reporter.

BTW, have you used or seen in a real project, a custom reporter that doesn't align with the official Snap! restriction?