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11702 :: Monoucha: a high level QuickJS wrapper

• nrk (orginal) [2024-06-03T22:06:47+02:00] view original

  A preview version of Monoucha, a high-level QuickJS wrapper, has been released:

  https://git.sr.ht/~bptato/monoucha

  Monoucha is aimed at projects that wish to embed the QuickJS engine with relatively little effort and/or changes to their existing code.

  It is not a goal of the project to abstract away the entire QuickJS API; you are encouraged to reach for that when needed. Instead, Monoucha builds on top of it, providing useful macros and functions for otherwise tedious operations:

  • You can automatically convert and transparently use Nim reference types in JS, without having to change your type hierarchies or resorting to manual reference counting.
  • Various macros exist to generate JS bindings for existing functions - in general, exposing existing code to JS just consists of tacking a .jsfunc pragma on your functions.
  • Converters exist for a wide range of basic value types, and it is possible to add your own value type converters too.

  As a bonus, I have also included a simple wrapper of the QuickJS regex engine in the jsregex module. (To-do: this is still undocumented.)

  Note that Monoucha uses a custom fork of QuickJS for better integration with the Nim runtime. I expect this to remain the case for the foreseeable future.

  Apart from QJS, the only dependency of Monoucha is nim-results.

  Of course, I wouldn't be calling it a "preview version" if it didn't come with some caveats:

  • The manual is still incomplete - will hopefully get it finished soon.
  • Only refc is supported. Monoucha uses some ugly hacks for synchronizing the QuickJS and Nim GCs, and I haven't managed to get this to work correctly with ORC yet.
  • Some blind spots in the QuickJS bindings exist. (I am looking into re-doing these with Futhark.)
  • The API has some known deficiencies, like using global (compile-time) state for macros, and registerType being too inflexible for some (I suspect quite rare) use cases.
  • Lack of support for function overloading. (For now, you can emulate it with generic type constraints.)

  Nevertheless, I have been using what is now Monoucha for a long time. I am releasing this version in the hope that it will be useful to others in its current form too.

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