Reverse Polish Notation Calculator

This project is written in Rust. To run this project please install Rust on your machine.

This is a small Reverse Polish Notation calculator written in Rust.

The rough idea is that a RPN calculator is a stack language: we push things onto a stack as we parse them, and when we parse operations we pop off the required number of arguments, apply the operation, and push the result back on to the stack.

Inputs

• Add (+): Add two numbers together. Sample input: 3 5 + should lead to 8.
• Eq (=): Check if two numbers or two booleans are equal. Sample input: 3 5 = should lead to false.
• Neg (~): Negate a boolean. Sample input: false ~ should lead to true.
• Swap (<->): Swap the top two elements of the stack. Sample input: 0 1 <-> [...] should lead to 1 0 [...].
• Rand (#): Produce a random integer from 0 to the top element of the stack (which must be non-negative). Sample input: 5 # [...] should lead to a uniform integer in {0, 1, 2, 3, 4}, followed by [...].
• Cond (?): If-then-else. Looks at the top three elements of the stack, and does an if-then-else. Sample input: true 1 2 ? should lead to 1, and false 1 2 ? should lead to 2.
• Quit (quit): Quit the calculator. (You can just return Error::Quit.)

Compilation instructions: To run this file with cargo, execute the following command:

$ cargo run