* Julia's type system can reflect on tuples just fine at both compile time and run time and we do so all the time.

Then why do I nowhere see that actually being done? Reflection on tuples should be done much like pattern matching on lists in functional languages. What is the point of that VarArgs nonsense? I know that Julia has pattern matching - now it needs to take the next step and actually make use of it.

Is this Julia's way of making itself familiar to C programmers?

I see those `...` elipses used as some kind of operator in both C++ (and Racket ironically) and they are a horrible idea as they are completely implicit and non-obvious in their function.

Using type membership tests + if statements is so 90s. Is Julia also trying to draw in the Java crowd here by trying to be closer to that language?

> <all those other points>

> There are many situations where being forced to know array dimensions at compile time is not helpful or even actively problematic.

It is not that Spiral enforces that dimensions be static. Rather if they are known at compile time then that information is merely propagated forward including through function call boundaries.

You seem to miss what it really means to have first-class types together with staging in a language. Spiral's tensors can be arbitrarily static or dynamic in their dimension and can even allow some dimensions to be static (known at compile time) while the others are dynamic. No friction results from this.

All this does not actually require separate implementations like in Julia. Both Spiral and Julia have Turing complete type systems, but based on this I can conclude that Spiral's is more expressive.

It would be trivial to force it so all the dimensions of a tensor are dynamic, but why would one want to propagate less information during compilation? It is not like dimensions of tensors change that often or arbitrarily like common variables do.

Also let me just state for the record that Spiral is intended to be more than a GPU language. A language with the capabilities of doing it elegantly was my motivation, but Spiral featureset makes it uniquely suited for both very high level and very low level programming.

A language saying it wants to be as fast as C counts for very little, the question is how fast it would be once the code starts being really abstract? This is why the rare one benchmark that currently exists in Spiral's documentation is for parser combinators.

GPU kernels are not a good test bed for language speed because they do not use that many high level features except for the ones needed for tensors. I'd be more concerned with all the scaffolding needed to set up the kernel. And in fact that was one of the majors concerns for me back when I was doing a ML library in F#.

https://www.youtube.com/watch?v=YRoruJRmuLc&t=2537s
Jeffrey M. Siskind – The tension between convenience and performance in automatic differentiation

In the field that Julia is aiming for, I'd rather see a benchmark for a CPU based AD library that works on scalars which is a use case in scientific computing. Optimizing this is actually difficult given that none of the mainstream functional languages can do it. I'd expect the same situation as with monads for Julia where the inliner just gives up.

> Of course, we're also cheating since Julia doesn't do type checking and therefore having a highly expressive type system doesn't really cost us much.

I do not know whether the code that was linked in these threads is a representative sample for Julia, but Julia's code to me looks much more like it was written in a static language than Spiral's does.

I think that language wars such as these are necessary in order to come to the truth. It is not that I am being rude on purpose, it is that rudeness in a battle is to be excused and seen as unavoidable. Being right is a process rather than a fact because being able to get it down to a fact is rare and getting the fact to be accepted is even rarer. Cooking a good meal requires flames.

Language semantics have indivisible algorithmic properties that set them apart from each other and hence they cannot ever be equal. The best thing therefore is to enjoy the division. I see this as different than celebrating diversity.