The feature in OxCaml that more languages should steal

7/4/2026 at 4:27:28 PM

Managed languages already had explicit stack allocation during the last century.

Unfortunately we went crazy with heap only types, on the other hand thankfully the pendulum is turning around and most compiled languages are having them back.

However nothing of this matters if you end up shipping the app inside Electron.

by pjmlp

7/4/2026 at 1:54:51 PM

> In most languages (Java, Go, C#, Rust, Zig, OCaml, etc.) the process is reversed: you take a profiler to try and find allocations (usually in loops that happen millions of times). Then you go and eliminate or minimize the allocations.

This isn't fully correct. In Zig, the common pattern is that any function which allocates accepts an explicit allocator parameter; if you don't pass one explicitly, you don't get any heap allocations.

Rust doesn't make things quite that visible. But, if you restrict yourself to the standard library and crates designed with this in mind, allocations are usually not too hard to find. And you can always use `#![no_std]` without `alloc` if you want to be sure. Neither language is ever going to insert a heap allocation if it's not somewhere in the source.

by Georgelemental

7/4/2026 at 9:00:59 PM

That's just not true. It's just a convention. You can assign the allocator to a global or use malloc from libc. The article is correct.

by 3836293648

7/4/2026 at 2:02:03 PM

could you clarify for me, because isn't that a different guarantee? from my understanding, Rust and Zig make allocations explicit, but [@zero_alloc] lets you declare "this function (and everything it calls) must not allocate" and have compiler enforce it.

by scritty-dev

7/4/2026 at 3:22:24 PM

They are indeed different. In Zig you might get the allocator via a struct field or just via importing the global allocator.

  const std = @import("std");

  fn makeBuffer(n: usize) ![]u8 {
      return std.heap.page_allocator.alloc(u8, n);
  }

Here are a few examples from the last release of Bun before the rewrite into Rust.

https://github.com/oven-sh/bun/blob/bun-v1.3.14/src/install/...

https://github.com/oven-sh/bun/blob/bun-v1.3.14/src/shell_pa...

The allocator via function parameter is only a convention and only even one convention. It is certainly a strong convention (throughout the standard library anyway) but it is just a convention.

Recent Rust also has the ability to pass allocators but that's the same thing. And even if you use no_std in Rust you might call into some other library's no_std function that allocates and you wouldn't be able to grep for that.

by eatonphil

7/4/2026 at 3:32:06 PM

If you don't pass an allocator param in Zig, then the function basically can't allocate.

by wmedrano

7/4/2026 at 2:26:39 PM

Can we extend this to more properties, such as: Does IO, makes system calls, launches or interacts with threads, may block or has an unexpected space/time complexity?

by xg15

7/4/2026 at 4:28:10 PM

Kind of, via effects, which is yet another way to use the type system to enforce specific kinds of execution flows.

by pjmlp