HQ9++

Introduction

HQ9++ is an object-oriented extension of the well-known esoteric language HQ9+, created by Cliff L. Biffle.

Design Principles

Extend the elegance, simplicity, and power of HQ9+ to the object-oriented paradigm.
Be backwards compatible with HQ9+. That is, any valid HQ9+ program will also run in HQ9++ and will produce identical output.

Language Concepts

HQ9+ was created to make some very common programming tasks extremely straightforward. HQ9++ bulds on this strong core functionality with the purest implementation of the object-oriented paradigm in any language.

Hello, World!

The quintessential test of a programming language is its ability to print the statement "Hello, World!" HQ9+ naturally allows the writing of this test program in a very efficient and straightforward manner.

99 Bottles of Beer on the Wall

A good test of a language's control flow and recursive capabilities is the ability to print the full lyrics to the song "99 Bottles of Beer on the Wall" with code as concise as possible. HQ9+ provides the definitive standard in this test.

Quines

A quine is a program that print its own source code. In most languages this requires some very tricky programming. HQ9+ again set a new standard for this test of a programming language's capability.

Objects

HQ9++ extends HQ9+ by allowing it to define and instantiate objects. HQ9++ is a so-called pure object-oriented language, in that all data is stored in objects - there are no simple variables such as the integers or chars which exist in "unpure" object-oriented langages such as C++ or Java.

Syntax Elements

HQ9++ has four syntax elements:

These are combined into five different commands, described below.

Commands

H
Prints "Hello, world!".
Q
Prints the entire text of the source code file.
9
Prints the complete canonical lyrics to "99 Bottles of Beer on the Wall".
+
Increments the accumulator.
++
When the sequence ++ is encountered, it (naturally) increments the accumulator twice, and also instantiates an object of a new subclass of the generic superclass. In line with the best data-hiding principles, there is no way to access this object.

Resources

The original HQ9+ specification, by Cliff L. Biffle.
A further extension of this amazingly versatile and useful language: HQ9+-, by melikamp.