Async Code Generator

A library for async code generation that imposes no ownership choices (can use borrowed or owned data) and is fully composable using generics and general-purpose structs.

Example

This may seem tedious, but the design allows for maximum re-usability and composability.

async fn write_function<O>(output: &mut O) -> Result<(), O::Error> where O: Output {
  // For more advanced usage, you can replace Str("") by other Writable implementations
  let function_def = FunctionDef {
    attr: SingularSeq(Deprecated::with_message(Str("because we all love deprecation"))),
    mods: SingularSeq(ModPub),
    decl: Function {
      name: Str("my_func"),
      args: CombinedSeq(
        SingularSeq(FunctionParam(Str("var1"), Str("Type"))),
        SingularSeq(FunctionParam(Str("var2"), Parameterized::new(Str("Option"), SingularSeq(Str("bool")))))
      )
    },
    return_type: Parameterized::new(Str("Box"), SingularSeq(Str("str"))),
    body: Str("\ntodo!()\n")
  };
  function_def.write_to(output).await
}

Will render as:

#[deprecated = "because we all love deprecation"]
pub fn my_func(var1: Type, var2: Option<bool>) -> Box<str> { 
  todo!()
}

Library Design

The API is conceptually simple. Performing code generation is akin to writing a syntax tree.

Model

Writable elements are composed from other writable elements. They are divided into two kinds:

Writable - the main trait used by the library
WritableSeq - for a sequence of writable values handled in the same way.

An example of a writable sequence would be function arguments, type variables, etc. An example of a standalone writable value would be a function body.

Async and Errors

Every code generation-related function returns the library user's error type.

Also, the methods are async and must be awaited as such. This lets the library user plug in their favorite async runtime... because why not make code generation fast?

Library

Safety

The library contains no unsafe code
The library should never panic, except where documented.

Dependency

Add this library to your Cargo.toml. Check crates.io for the latest version.

[dependencies]
async-codegen = "0.4.0"

Licensing

Licensed under the Apache License v2.0. See the LICENSE.txt.

async-codegen 0.4.0