siddg97 / RPN-Calculator

A RPN(Reverse Polish Notation) Calculator. Evaluates postfix expressions

Reverse Polish Notation Calculator in Haskell:

• This project was a university assignment that was required by me to do.
• To run this project you will need the haskell-platform and the ghci interpreter.
• If you are using a linux device then you can run the following command:

sudo apt install haskell-platform ghci

• After you have installed the above dependecies, you can go to the root directory of this repository (Once you clone this repo on your system) and run the following command:

ghci calc.hs

• The above command will run an interpreter and now you can evaluate any RPN expression like this:

Main> calc "1 2 + 3 - 1 /"
> "0"

Operators Supported:

The following operators are unary:

• inc

    Main> calc "3 inc"
    > "4"
    Main> calc "3 inc inc"
    > "5"

• dec

Main> calc "3 dec" 
> "2"
Main> calc "3 dec dec"
> "1"

• sqrt

Main> calc "3 sqrt"
> "1.7320508075688772"

• sin

Main> calc "3 sin" 
> "0.1411200080598672"

• cos

Main> calc "3 cos"
> "-0.9899924966004454"

• inv

Main> calc "3 inv"
> "0.3333333333333333"
Main>calc "0 inv"
> "Infinity"

The following operators are binary:

• +

Main> calc "4 2 +"
> "6"

• *

Main> calc "4 2 *"
> "8"

• -

Main> calc "4 2 -"
>"2"
Main> "2 4 -"
> "-2"

• /

Main> calc "4 2 /"
> "2"
Main> calc "2 4 /"
> "0.5"
Main> calc "2 0 /"
>"Infinity"
Main> calc "0 0 /"
> "NaN"

• +all

Main> calc "1 2 3 4 +all"
> "10"
Main> calc "4 +all" 
> "4"

• *all

Main> calc "1 2 3 4 *all"
> "24"
Main> calc "4 *all"
> "4"

The following operators manipulate the args:

• dup

Main> calc "4 dup *"
> "16"

• pop

Main> calc "4 5 6 pop +all"
> "9"

• clear

Main> calc "1 2 3 clear"
> ""

• swap

Main> calc "4 1 -"
> "3"
Main> calc "4 1 swap -"
> "-3" 

Some examples:

Main> calc "1 2 + 3 *"
> "9.0"

Main> calc "1 2 3 * +"
> "7.0"

Main> calc "2 sqrt 3 sqrt +"
> "3.1462643699419726"

Main> calc "11 dup *"
> "121.0"

Main> calc "0 5 /"
> "0.0"

Main> calc "5 0 /"
> "Infinity"

Main> calc "2 3 + 4 2 +all"
> "11.0"

Main> calc "2 3 + 4 2 *all"
> "40.0"

Main> calc "3.2 sin dup * 3.2 cos dup * +"
> "1.0"