sandwich/src/eval.rs

use std::io;
use std::io::Write;

pub fn do_math(arguments: String, operator: char) -> u32 {
    let split_args = arguments.split("-").collect::<Vec<&str>>();

    let num1: u32 = match split_args[0].parse() {
        Ok(num) => num,
        Err(_e) => panic!("ArgumentError: Not a number: {}", split_args[0]),
    };

    let num2: u32 = match split_args[1].parse() {
        Ok(num) => num,
        Err(_e) => panic!("ArgumentError: Not a number: {}", split_args[1]),
    };

    match operator {
        '+' => num1 + num2,
        '-' => num1 - num2,
        '*' => num1 * num2,
        '/' => num1 / num2,
        _ => panic!("SyntaxError: Unknown operator {}", operator),
    }
}

pub fn args_or_comments(arguments: &str) -> String {
    let argument_vec: Vec<char> = arguments.chars().collect();
    let mut builder: String = String::from("");

    for char in argument_vec {
        if char == '#' {
            break;
        } else {
            builder.push_str(&char.to_string());
        }
    }

    builder
}

pub fn read_stdin(prompt: &str) -> String {
    print!("{}", prompt);
    io::stdout().flush().unwrap();

    let mut result = String::new();
    io::stdin().read_line(&mut result).expect("Expected a string!");

    result.trim().to_string()
}

pub fn inp_or_normal(value: &str) -> String {
    let value_vec: Vec<char> = value.chars().collect();

    if value_vec[0] == '<' {
        let prompt: String = value_vec[1..].into_iter().collect();

        return read_stdin(&prompt);
    } else {
        return value.to_string();
    }
}