A generic operator-precedence parser for Rust. You plug your own handler function, token struct, and operator enum, and this crate provides the algorithm.

Simple example is available in int_math.rs

sh cargo run --example int_math

Example

```rust

fn handler(lhs: f64, op: Op, rhs: f64, _ctx: &()) { match op { Op::Add => lhs + rhs, Op::Sub => lhs - rhs, Op::Mul => lhs * rhs, Op::Div => lhs / rhs, Op::Exp => lhs.powf(rhs) } }

let climber = Climber::new( vec![ Rule::new(Op::Add, Assoc::Left) | Rule::new(Op::Sub, Assoc::Right), Rule::new(Op::Mul, Assoc::Left) | Rule::new(Op::Div, Assoc::Right), Rule::new(Op::Exp, Assoc::Right) ], handler );

// 2 + 2 * 3 // 2 + 6 // 8 let expression = Expression::new( 2.0f64, vec![ (Op::Add, 2.0f64), (Op::Mul, 3.0f64) ] );

assert_eq!(climber.process(&expression, &()), 8.0f64); ```

This crate is heavily based on the Pest parser's PrecClimber, but is a more generic implementation for non-Pest use.