Add compile-time @range and runtime range/trange

[NotsoanoNimus]

This pull request depends on changes from #2378 -- that PR should be merged before this one. I will fix merge conflicts.

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Adds a compile-time and runtime range functionality, similar to python's range function.

    // compile-time ranging
    $foreach $sample : @range(17):
        $echo @sprintf("SAMPLE: %s", $sample);   // prints "SAMPLE: 0" -> "SAMPLE: 16"
    $endforeach

    // runtime ranging - prints "[0, 2, 4, 6]"
    io::printfn("%s", array::trange(stop: 6, step: 2, inclusive: true));
    // below prints "[-2, 0, 2, 4, 6]"
    io::printfn("%s", array::trange(-2, 6, 2, true));

Compile-time ranges are fun to splat with:

    isz[] some_sequence = { 1, 2, 3, ...@range(4, 150, $inclusive: true) });

[lerno]

This seems to overlap a bit with math::iota ?

[NotsoanoNimus]

This seems to overlap a bit with math::iota ?

There is overlap for sure, but only where the desired array is sequential, from zero, and bound to a type's width; like array::trange(64) or @range(64) ==> math::iota(char[64]). Except iota produces char[64] and the others produce isz[].

However, the sequence of numbers produced by range can be more expressive and dynamic, so iota is really only a subset of it. If I wanted to generate test inputs or array indexes like [-10, -7, -4, -1, 2, ...] (imagine this is much larger), for example, iota cannot do that.

[NotsoanoNimus]

Fixed merge conflicts. Added the ability to specify the resulting array's type, so it can be more flexible as needed. Also introduced a few more related unit tests.

This will now be marked ready for review, provided all CI checks pass.

[lerno]

You could extend this to be usable with any type supporting + / and comparison.

Using $defined(start_stop + 1) and $defined(start_stop + step) and so on. You can start by writing the general code, then add the constraints.

[lerno]

Ping!

[NotsoanoNimus]

@lerno I still plan on making your suggested changes! This fell by the wayside thanks to an extended vacation, but I'm working on catching up mentally to any language changes since my absence. Please give this another week or so for an update with your changes to appear (hopefully less), thanks. 🙏