mex a parser/evaluator for simple mathematical expressions, with no dependencies at all. Currently, it supports only a tiny amount of syntax. Here are some valid expressions:

```

10 10

10 - 3 * 10 -20

π = 3.1415926536 3.1415926536

5 * π 15.707963268 ```

And that's it, for now.

It supports the following operators: +, -, *, /, =.

But it's easy to add more (by editing the source).

The crate can be used as a binary or a library. The binary is a REPL, where you enter single expressions line by line and get the result given back to you. An example of the library is below:

```rust use mex::parser; use mex::evaluator; use mex::evaluator::context; use mex::evaluator::object;

fn main() { let input = "2 * x"; let mut parse = parser::Parser::new(input);

let mut context = context::Context::new();
context.set(&String::from("x"), object::Object::Number(13.5));

match parse.parse() {
    Ok(node) => {
        match evaluator::eval_node_in(node, &mut context) {
            Ok(result) => println!("{}", result),
            Err(err) => println!("eval error: {:?}", err),
        }
    }

    Err(e) => println!("parse error: {:?}", e),
};

} ```

In the future, I'd like to add these things: