jason-RS

jason is a lightweight JSON templating tool that transforms reusable .jason files into standard JSON. Build modular and composable JSON structures with parameter support and file inclusion.

✨ Features

Template Parameters - Define reusable templates with named parameters
File Inclusion - Compose JSON from multiple .jason files
1:1 Conversion - Clean mapping from .jason syntax to standard JSON
Library-First - Designed for seamless integration into Rust projects

🚀 Quick Start

Add jason-rs to your Cargo.toml:

[dependencies]
jason-rs = "0.2.5"

Parse a Jason file:

use jason_rs::jason_to_json;

fn main() {
    //outputs raw json source
    let json = jason_to_json("./Page.jason").unwrap();
    println!("{}", json);
}

Example

Jason File

// a variable that holds an object of those fields
alex = {
    name: "Alex",
    project: "jason-rs",
    money: 0,
}

//what gets exported at the top level
out alex

Jason Templates


Dev(name, project, money) {
    name: name,
    project: project,
    money: money,
}
// invokes the template and fills in the variables with the passed in arguments
out Dev("alex", "jason-rs", 0)

importing

Dev.jason - A file containg the dev template

Dev(name, project, money) {
    name: name,
    project: project,
    money: money,
}

main.jason - The top level file being compiled

import(Dev) from "./Person.jason"

out Dev("alex", "jason-rs", 0)

note: this will not import the context around DEV so variables will be ignored unless imported as well. this warning will be patched in a later version with groups.

Syntax Overview

Syntax	Description
`name(arg1, arg2, ...) {...}`	Defines a template name
`name() {...}`	Defines a template name
`name {...}`	Defines a template name
`name = ...`	Defines a variable name
`name(...)`	invokes a template
`import(template, variable, ...) from "path/to/file.jason"`	imports templates and or variables from file

Parses a .jason file at the given path and returns a serde_json value object which can then be converted to structs

License

Licensed under the Apache License 2.0. See LICENSE for details.

jason-rs 0.2.6