4 ms·

Rust has an extremely powerful macro system, have you tried that?

• alpaca128 4y ago
  Rust macros are one of the more annoying features to me. They're great at first glance but whenever I want to build more fancy ones I constantly bump into limitations. For example they seem to be parsed without any lookahead, making it difficult to push beyond the typical function call syntax without getting compiler errors due to ambiguity.
  • inferiorhuman 4y ago
    Procedural macros have a peek function from the syn crate. macro_rules macros can stuff this into the pattern matching. e.g. https://turreta.com/2019/12/24/pattern-matching-declarative-macros/ https://turreta.com/2019/12/24/pattern-matching-declarative-...
    • colejohnson66 4y ago
      But proc macros are limited by requiring another crate (unless things have changed in the last year). Sure, it’s just one extra crate in the project, but why must I be forced to?
      • inferiorhuman 4y ago
        Asked and answered in an adjacent comment.
• xigoi 4y ago
  But there's the weird limitation that procedural macros have to be in a separate crate.
  • efaref 4y ago
    Why is that weird? Procedural macros are compiler plugins. They get compiled for the platform you're building on, not the one you're building for, and so they need to be a separate compilation unit. In Rust, the crate is the compilation unit.
    • xigoi 4y ago
      Because you can't just throw together a simple procedural macro to use in a specific project, as you can in other languages.