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Comment by greybox | Hacker News Reader

I love nim, but I disagree with the "quick compilation" point here. The compilation is horrendously slow. (by default it compiles down to C, then to exe from there).

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As with most things, "it depends". If you compile very macro compile-time virtual-machine heavy code that can be slow. If you compile to the c++ backend then that backend process can be slow. If you invoke some macro that generates mountains of Nim code translated to continents of C code it can be slow. If you use the default `nim.cfg` that has gcc -Og it can take a lot longer than gcc -O0, for example. Meanwhile, if you use the `tcc` backend even without incremental compilation it can be close to immediate feedback:

    $ touch foo.nim
    $ /usr/bin/time nim c foo.nim
    CC: ../usr/lib/nim/lib/std/private/digitsutils.nim
    CC: ../usr/lib/nim/lib/system/dollars.nim
    CC: ../usr/lib/nim/lib/system.nim
    CC: foo.nim
    Hint: gc: refc; opt: none (DEBUG BUILD, `-d:release` generates faster code)
    36891 lines; 0.154s; 39.434MiB peakmem; proj: /tmp/foo.nim; out: /tmp/foo [SuccessX]
    0.24user 0.02system 0:00.27elapsed 101%CPU (0avgtext+0avgdata 44360maxresident)k
    0inputs+0outputs (0major+13676minor)pagefaults 0swaps

(I point my default backend compiler to tcc in my $HOME/.config/nim/nim.cfg.) There are some more details in this nim forum thread: https://forum.nim-lang.org/t/8677

Unless your standards are "single digit milliseconds per file like tcc itself, please!", 240 ms is not so bad. (EDIT: And this is just on some 2016-era Intel i7-6700k box, not some liquid helium cooled 10 GHz whatever.)

It's much faster than C++, Rust, Go and many others.

I'm assuming this must be for huge projects?

I just compiled my toy project (detecting anomalous parity in integers) in nim 1.6.6 (4.23s), go 1.17.7 (2.43s to create both aarch64 and x86_64 binaries), zig 0.8.0-dev.1140 (2.04s to create aarch64 and x86_64 binaries) and C via clang 13.1.6 (0.14s).

nim's compilation is 175% of Go, 207% of zig, and 3021% of clang.

Thanks for the data; that's what I call an elegant rebuttal.

No, even small files. You must have issues with your setup. Are you sure your compiler is not built in debug mode?

How would I check that? I installed it through homebrew via https://github.com/Homebrew/homebrew-core/blob/HEAD/Formula/... which doesn't seem to mention debug mode anywhere?

Run `nim -v`, if it's not in debug mode you should see "active boot switches: -d:release".

Looks like it isn't in debug mode after all.

    $ nim -v
    Nim Compiler Version 1.6.6 [MacOSX: arm64]
    Compiled at 2022-05-05
    Copyright (c) 2006-2021 by Andreas Rumpf
    
    active boot switches: -d:release -d:nimUseLinenoise

how are u compiling (optimization, custom compilation flags etc.?) In my case https://github.com/mratsim/Arraymancer big project compile under your 4.2s so or you have like 10k+ lines of codes with macros or you just pass some debug flags to compiler :D

Compilation command is:

    nim c -d:release --passC:"-flto" --gc:markAndSweep --out:ap ap.nim

I will add that once it's been run a few times, it does go a bit quicker (down to ~0.7s) but the Go also gets quicker (down to 0.28s for two outputs when files are cached.)

No, it is not - Nim's compiler backend is extremely complex and full of cruft. I've been around Nim for 7+ years now and there's a reason the compiler was hard forked.

Nim's compiler is definitely not speedy, and this is why so much effort has been spent on incremental compilation, which tmk, still isn't working - https://github.com/nim-lang/Nim/issues/19757.

In comparison to languages like Rust and C++ it compiles pretty fast. Or maybe you built the compiler in debug mode.

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