# RPN(Reverse Polish Notation) Calc
Reverse Polish Notation (RPN) Calc.
## Installation
```
cargo add rpn_lib
```
## Example
```
fn main() {
let src = String::from("1 2 + 3 * ");
let a = rpn_lib::eval(src).unwrap();
println!("{}", a); // →9
}
```
## Example2
```
fn main() {
let result = rpn_lib::eval_from_str("1 2 3 * +");
println!("{}", result); // →7
}
```