Reverse Polish notation (RPN) calculator

The purpose here is to design a function that parse and evaluate a calcul describe using reverse polish notation

Using RPN we can get rid of parenthesis. For instance:

• (4 + 3) * 2 could be written 4 3 + 2 * or 4 3 2 + *
• (4 - 3) * 2 could be written 4 3 - 2 * or 4 3 2 - *
• (4 - 3) + 2 could be written 4 3 - 2 + or 4 3 2 - +

For this exercice, we will be focusing on parsing and evaluating the first kind of RPN notation, (without all the operator at the end) like 4 3 - 2 +.

Stack

We will use typescript with strong type checking expressed in tsconfig.json and backed by eslint for linting and formatting.

There is already 2 existing test case in src/test/rpn-calculator.spec.ts, don't change them ! But feel free, to add new ones or even new test suites.

Tests are written using jest.

You can run them by using

npm run test

or to run them on every file change

npm run test:watch

The function to be developed is in src/main/rpn-calculator.ts.

Tips

Don't hesitate to refacto your code to make it expressive and readable.

You can read this article for a few good advices about clean code

You can try TDD methodology, here is a good article that talk about it