krush-engine: The engine that powers the Kreative Rust Shell

The krush-engine is a library that has a simple command parser and interpreter that is used for the krush shell interface, but can be used standalone.

What it does?

Once you've defined an Engine with all the commands you want using the register_command method. You can call the method evaluate with a String which returns a Result. The first word of this string is the command name, if you've registered a command with that name, the Engine will parse the rest of the input to get the arguments you've setted. If everything goes right, your callback function will be called.

TODO

• List of any Type
• Support quoted strings in List

Note

This project were written in a day to be used for my homework so there are several unimplemented features and potential bugs (actually, krush doesn't even exists at the moment).

Changelog

v0.3.0

• Now a Engine can be captured by a thread closure
• Values captured by a definition closure must be Arc<Mutex>
• A defition closure must be a move closure

v0.2.0

• Now a Definition uses a closure instead of a function pointer, which allows to modify values in the surrounding context by putting them into Cell or RefCell(for types who doesn't implement the Copy trait)
• Added definition! macro which creates a new Definition from an array of Type and a closure.

Example:

use std::cell::{Cell, RefCell};

use krush_engine::{Engine, Definition, Type, definition};

fn main() {
    let last = RefCell::new(String::new());
    let count = Cell::new(0);
    let mut engine = Engine::new();

    engine.register_command("print", definition!([Type::Str], |args| { 
        let text = args[0].unwrap_str().unwrap();
        println!("{}", text);

        *last.borrow_mut() = text;
        count.set(count.get() + 1);

        None 
    }));

    let _ = engine.evaluate("print \"Hello World!\"".to_string());
    println!("Last is: {}", last.borrow());

    let _ = engine.evaluate("print \"This is Krush Engine!\"".to_string());
    println!("Last is: {}", last.borrow());

    let _ = engine.evaluate("print \"Thank You!\"".to_string());
    println!("Last is: {}\nCount is {}", last.borrow(), count.get());
}

Output:

Hello World!
Last is: Hello World!
This is Krush Engine!
Last is: This is Krush Engine!
Thank You!
Last is: Thank You!
Count is 3