Show HN: Zig-DbC – A design by contract library for Zig

Hi everyone,

I've made an open-source library for using design by contract (DbC) principles in the Zig programming language.

It's called Zig-DbC, and it currently provides the following features:

- A simple API to define preconditions, postconditions, and invariants.

- Contracts are active in `Debug`, `ReleaseSafe`, and `ReleaseSmall` modes to catch bugs early.

- All checks are removed at compile time in `ReleaseFast` mode for zero performance cost.

- An optional mode to handle partial state changes in functions that return errors.

- Transparent error handling that propagates errors from your code to the caller.

Project's GitHub repo: https://github.com/habedi/zig-dbc

42 points | by habedi0 3 days ago

5 comments

  • skyzouwdev 4 hours ago
    Nice! Always thought DbC was underused outside of languages like Eiffel. Cool to see it brought to Zig with zero-cost checks in ReleaseFast — that’s a solid balance between safety and performance.
  • skavi 10 hours ago
    Why are the checks included in ReleaseSmall?
    [-]
    • habedi0 9 hours ago
      I created this library to help me verify the correctness of my Zig code in another project. However, I wanted the option to strip the checks when the code becomes more mature, for efficiency. For efficiency, I mainly care about speed, which is why checks are only compiled out in `ReleaseFast`.
  • metalliqaz 22 hours ago
    This is pretty cool, I like to see this kind of project coming to Zig. Zig's compile-time language features make DbC a natural fit.

    I am not yet proficient enough in Zig to be able to evaluate how well the syntax fits into idiomatic Zig.

    Good work.

    [-]
    • habedi0 22 hours ago
      Thanks.

      I'm new to Zig myself and created this library because I had trouble verifying the correctness of the code I wrote for a set of complex data structures in another larger Zig project (this one: https://github.com/habedi/ordered). I'm currently experimenting with how to use DbC in Zig, which led to the creation of this library.

  • Defletter 7 hours ago
    Another project burdened by Andrew Kelley's weird hate-boner for function literals.

        (struct { fn run }).run
    How ridiculous that this is required to do something so simple.