HPL in Java

Code challenge: interpret an esoteric programming language

This repository contains code in Java for resolving the challenge stated below. The HPL is a version of the esoteric language BrainFuck.

Challenge Introduction

You find a strange mirror that always shows a hand that is moving. The hand appears to be alive, and after a lot of questions of "yes" and "no" answer, you know that the hand is trying to teach you a program that is written in HPL (Hand Programming Language).

This language works with a memory of an indefinite size of bytes, with all values initialized to 0. This language haves 7 instructions:

👉 : moves the memory pointer to the next cell

👈 : moves the memory pointer to the previous cell

👆 : increment the memory cell at the current position

👇 : decreases the memory cell at the current position.

🤜 : if the memory cell at the current position is 0, jump just after the corresponding 🤛

🤛 : if the memory cell at the current position is not 0, jump just after the corresponding 🤜

👊 : Display the current character represented by the ASCII code defined by the current position.

Notes

• As memory cells are bytes, from 0 to 255 value, if you decrease 0 you'll get 255, if you increment 255 you'll get 0.
• Loops of 🤜 and 🤛 can be nested.

Tests

The hand shows you two small programs and their outputs:

This program display "Hello"

👇🤜👇👇👇👇👇👇👇👉👆👈🤛👉👇👊👇🤜👇👉👆👆👆👆👆👈🤛👉👆👆👊👆👆👆👆👆👆👆👊👊👆👆👆👊

This program (with nested loops) display "Hello World!"

👉👆👆👆👆👆👆👆👆🤜👇👈👆👆👆👆👆👆👆👆👆👉🤛👈👊👉👉👆👉👇🤜👆🤛👆👆👉👆👆👉👆👆👆🤜👉🤜👇👉👆👆👆👈👈👆👆👆👉🤛👈👈🤛👉👇👇👇👇👇👊👉👇👉👆👆👆👊👊👆👆👆👊👉👇👊👈👈👆🤜👉🤜👆👉👆🤛👉👉🤛👈👇👇👇👇👇👇👇👇👇👇👇👇👇👇👊👉👉👊👆👆👆👊👇👇👇👇👇👇👊👇👇👇👇👇👇👇👇👊👉👆👊👉👆👊

Challenge

The file "input.hand" is the code of the program