Hacker News Reader

Comment by xiaodai | Hacker News Reader

Agree with everything you've said, it's hard to see why one would prefer Swift over Julia for numerical computing. I use Julia for it's regex too; it's just nicer. Hopefully, the data munging packages in Julia can catch up to dplyr and data.table, then we are talking!

View on HN

I am a happy Julia user, but I can imagine if you had a use case where you wanted to compile a binary or shared library, Julia could be a pain.

C++ of course works fine for this but I imagine Swift would be less terrifying to use.

I see a lot of great numerical code in Julia. As a C++ developer, I don’t want to deal with a runtime or various parts of the language, but I imagine I could be more easily brought to the table if Julia code could be exported to a shared object file and linked against, or if it could compile to a direct binary.

I think Julia is the dark horse to eventually take over a wide swath of computing - possibly wider than Java or C++. As others have pointed out there's an effort to produce static Julia executables, and I think it's already possible to produce libraries. One interesting datapoint is that Julia's C FFI is faster than that of C++...

https://github.com/dyu/ffi-overhead

(For those interested, the order of the first few languages is: lua-jit, julia, c(!), c++, zig, nim, d in order of decreasing speed.)

It's extremely well thought out, concise, powerful, and readable. I think Julia's approach to types and multiple dispatch is a better alternative to traditional OO programming.

One thing the author didn't point out is that C++ (clang), Swift, Rust and Julia all use the LLVM infrastructure, resulting in extremely similar if not identical code generation. If datacenter efficiency truly becomes a priority, highly efficient languages like Julia, Rust and Swift will see increasing use for general purpose programming.

Do you know how Julia gets such great ffi performance? Is it inlining, for instance?

It's a bit of a JIT party trick by emitting the target address directly rather than going through the PLT.

I think it will happen in the medium term future:

https://juliacomputing.com/blog/2016/02/09/static-julia.html https://github.com/JuliaComputing/static-julia https://github.com/JuliaComputing/llvm-cbe

https://github.com/queryverse/Query.jl Allows for dplyr syntax to work with any iterable and custom table types using traits...So I think it's already beating R data munging in the flexibility department.

Still missing some verbs, but these will be added.

Given Julia has macros, so it will definitely catch up to R and data.table in terms of syntax (if it's not already there). I am more thinking about performance, e.g see https://h2oai.github.io/db-benchmark/. It shows that Julia is lagging behind on group-by (and from my experience many other operations) when compared to R's data.table.

Although I have done some work to make thing fast see: https://github.com/xiaodaigh/FastGroupBy.jl. I have yet to update it to Julia v1. Hopefully, I will get to that soon. However, the improvement I have made only works for grouping up to 2 group-by variables and I need to learn more about generated functions to make the code more generic. So from my (someone who's actually spent time trying to optimise these data operations) perspective, Julia will take a while to catch up. Hats off to the data.table crew!

Ah yes, that is true. However Julia is tackling a harder problem in that the speed lag is presumably due to optimizing for custom element and table types.

"for custom element and table types" that is highly likely to be true, but unless an equally fast Julia program exists I remained scientifically skeptical. But my prior believe is that Julia can be as fast.

DataFrames.jl doesn't parameterize on its types and tries to rely on function barriers to be fast enough. That's what gives it the speed issue. IMO this isn't the best idea. It's not difficult to write a data table that's easier to optimize than that, but you would have to give up some of the flexibility.

Reply on news.ycombinator.com