rpn 0.1.0

Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27

extern crate rpn;
use std::io::{self, Write};

fn main() {
  println!("Reverse Polish Notation.");
  println!("Type quit to exit");

  loop {
    print!("> ");
    io::stdout().flush().expect("flushing failed");
    let mut input = String::new();

    io::stdin().read_line(&mut input)
      .expect("failed to read line");

    if input.trim() == "quit" {
      break;
    }
    let result = rpn::evaluate(&input);
    if result.is_err() {
      println!("Error: {}", result.unwrap_err());
    } else {
      println!("{}", result.unwrap());
    }
  }
}