Here's a nice recent example: a new reverse!(A; dims) function, which is fast and works on arrays with any number of dimensions. And is completely indifferent to where the indices start:
https://github.com/JuliaLang/julia/pull/37367/files#diff-eb9...
If by indexing you only mean adding offsets to pointers with your bare hands, this is possible but discouraged. Because you'll produce a buggier and less general version of exactly what already exists. In this case, reversing an N-dimensional array, along any M of its axes, with arbitrary offsets -- there are a lot of ways to get that wrong.
# one dimensional
a = [1, 2, 3]
# prints the number 1 @ index 0
print(a[0])
# multi-dimensional
b = [[1, 2, 3], [4, 5, 6]]
# prints the number 4 @ index (1, 0)
print(b[1][0])
In Julia these indexes would start from 1. It doesn't seem like `CartesianIndex` solves this, since looking at some examples you still have to specify array indexes (Which start from 1): https://docs.julialang.org/en/v1/base/arrays/#Base.Iterators...I also think it’s blurry as to whether mathematicians and programmers see indexing numbers as merely indices or richer numbers.
This is actually the other way around -- Method JITs are harder to implement and all the major JavaScript JITs are method JITs, not tracing JITs. There are many reasons that contribute to the latency but I don't see what makes method JITs inherently slower than tracing JITs.
Doing machine learning stuff in Julia is simply much more user friendly than doing the same in Swift. Swift is nice for iOS development, but I think in data science and Machine Learning Julia will always be a much better choice.
It is a pity Google did not go for Julia. Julia has gotten exceptionally far despite limited resources. With Google style resources, Julia could have been massive.
Despite modest investment, the Julia JIT beats almost anything out there. It would have been amazing to see what they could have pulled off if they had put the kind of resources that was put into the JavaScript V8 JIT into the Julia JIT.
Julia uses a method JIT, which are quick to implement, but which makes latency gets bad. Meaning if you load a whole new package, running the first function can cause some delay. With a JavaScript style tracer JIT added into the mix one could have probably managed to have both high performance and low latency.
Alternatively with more investment they could have had better precompile caching, meaning libraries that had been loaded in the past would JIT really fast. Julia does that today, but it could have worked a lot better than it currently does. It isn't that it can't be done, but it just requires resources.