Reverse Polish Notation (RPN) Calculator

Command-line based RPN calculator.

Getting Started

These instructions will get you a copy of the project up and running on your local machine for development and testing purposes:

git clone git@github.com:RezaMor/rpn_calculator.git

git checkout develop

import the project in eclipse, IntelliJ IDEA, or other suitable IDEs

run the main function in the Main.java

Prerequisites

In order to run the project you need to install:

Java 8 (the project is NOT compatible with earlier versions of Java)

Tests require JUnit

Introduction

The calculator has a stack that can contain real numbers.

The calculator waits for user input and expects to receive strings containing whitespace separated lists of numbers and operators.

Numbers are pushed on to the stack. Operators operate on numbers that are on the stack.

Available operators are +, -, *, /, sqrt, undo, clear
Operators pop their parameters off the stack, and push their results back onto the stack.
The clear operator removes all items from the stack.
The undo operator undoes the previous operation. "undo undo" will undo the previous two operations.
sqrt performs a square root on the top item from the stack
The +, -, *, / operators perform addition, subtraction, multiplication and division respectively on the top two items from the stack.
After processing an input string, the calculator displays the current contents of the stack as a space-separated list.
Numbers should be stored on the stack to at least 15 decimal places of precision, but displayed to 10 decimal places (or less if it causes no loss of precision).
All numbers should be formatted as plain decimal strings (ie. no engineering formatting).
If an operator cannot find a sufficient number of parameters on the stack, a warning is displayed: operator <operator> (position: <pos>): insufficient parameters
After displaying the warning, all further processing of the string terminates and the current state of the stack is displayed.

Running Tests

Please run the test in eclipse, IntelliJ IDEA, or other suitable IDEs