alurm

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27 days agodiscuss

Yeah, I've added macros `vec_len` and `vec_ptr` (or, enums, actually), which help somewhat.

`arr[3]` should be flagged by the compiler it is known to the compiler that you're operating on an array.

You can pass `arr` as `&arr` to functions, then compiler will know the length of the array since the type would be `T ()[2]`.

And you can then use it like this:

  void f(int *(*ints)[2]) {
      for (size_t i = 0; i < (size_t)vec_len[*ints]; i++) printf("f: %d\n", vec_ptr[*ints][i]);
  }

Curiously, this is a rare case where the "inverted" `a[b]` requires less typing compared to `(b)[a]`.

A compiler will not be able to flag `vec_len[ints]` though, which is unfortunate.

27 days agodiscuss

Thank you! I implemented this pattern initially about a year ago, but decided to write about it now. Since you liked it, it wasn't for nothing. :)

27 days agodiscuss

You're right, I added some more clarity in the README.

Interestingly, I think my approach will work fine on CHERI, since the pointer is never dereferenced, but I didn't test this. But yeah, there are some architectures where it would fail.

27 days agodiscuss

Good point! Added `vec_ptr[vec]` and `vec_len[vec]` helpers to mitigate this somewhat.

27 days agodiscuss

Thanks for mentioning it, I've heard about stb, but this time around I actually looked at the code. Their approach is very nice.

4 months agodiscuss

Making a strict subset of some existing language (Go) be a "better C" is quite an interesting idea compared to others (D, Zig, Hare, C3, D, ...), haven't seen it elsewhere. No new syntax. And Go seems to be a pretty good choice for this. Not sure if it's gonna fly though.

11 months agodiscuss

Yes, but you can generate JSON with other tools easily. home.md describes how you can do it with Nix, but just as easily you can use Cue or something else.

Edit: mentioned this in the README explicitly. Thanks!

11 months agodiscuss

Yeah, in general (a bit of a tangent), ideas from Plan 9 are really powerful. For example, the Acme text editor exposes it's API as a file system (it's represented via Unix sockets in plan9port, but FUSE is available as well there). It's easy to write scripts to manipulate the editor, and quite fun.

11 months agodiscuss

Well, if you're generating JSON with Nix, you don't have to put everything inside of one file. It would be a better idea to split it up into multiple. You can also use builtins.readFile for reading config files which don't have to be generated in a complex manner. It's up to you to choose, I just kept everything inside of one file since it makes for a simpler example.

Edit: I have updated the documentation to mention this explicitly, thanks!

11 months agodiscuss

YSH looks very nice here, thanks. I thought to mention YSH, but have no experience with it, so I hoped you would comment.

(I guess we're duplicating threads at this point :D)

11 months agodiscuss

Sure.

I have tried Bash namerefs. I found them to be kinda awkward, since you need to name them uniquely. So, you have to pretend that they are global variables, even though they are declared inside a function, which makes their usage verbose.

Here, this could look like:

  split_by_double_dash() {
    declare -n split_by_double_dash_before=$1
    declare -n split_by_double_dash_after=$2
    
    split_by_double_dash_before=()
    split_by_double_dash_after=()

    ...
  }

11 months agodiscuss

Yeah, PowerShell and nushell are pretty cool, I hope they gain more adoption.

12 months agodiscuss

Location: Yerevan, Armenia.

Remote: yes.

Willing to relocate: yes.

Technologies: Rust, C/C++, Bash, Go, Linux, Nix.

Résumé/CV: https://alurm.github.io/resume/alan-urmancheev.html (or .pdf for a PDF).

Email: [email protected].

A systems programmer. Prefer US opportunities.

2 years agodiscuss

I like your approach.

(Implicitly) using [1] instead of [false] as a default is less typing for sure (but maybe a bit more confusing?).

Also, objects being switched on really have to be tables in my version anyway (since overriding __call for builtin types seems harsh to me), so having a tag field right in them as opposed to creating a metatable should be more efficient.

For my version I'll add a value-weak map of metatables to dedup them, should work as well.

In terms of functions, yeah, I don't think you can get rid of them, but (in the example) you can avoid (r) and (s) params if you assume that the functions lexically close over shape.

2 years agodiscuss

Honestly, not much.

I found it nice how it's possible to emulate switches in Lua with so little code, without the result looking too ugly. You may find this pattern useful. That's it.

The catch is that, unlike with normal switches or with a series of "if"s, there's a whole bunch of indirection added via functions, so it's not very efficient.

Perhaps LuaJIT can inline these functions, but I haven't tested it.

2 years agodiscuss

Thanks, fixed.

2 years agodiscuss

https doesn't make content trust worthy.