The Elements of Programming

 

There are very few essential elements one needs for programming:

1. variables (things to store information), i.e. local variables and object's properties in the MOO language.
2. procedural abstractions (named collections of instructions), i.e verbs in the MOO language
3. branching (IF's)
4. side-effects (``Set'', ``=''), to assign values to variables
5. procedure/function calls
6. loops (as ``cheap'' alternative to procedure calls)

Those major elements rely on a number of things like:

• primitive data structures, e.g. numbers and symbols
• input/output functions
• libraries of useful procedures and functions

To make a programming language useful, you also need things like:

• Ways to build compound data structures (e.g. lists, arrays, records, objects)
• Complex conditions and several kinds of loops
• Error handling mechanisms

Many programming languages have special features that make them useful for a given task, e.g. the MOO language has:

• A sophisticated permission system
• Threads (forks for ``parallel'' execution of code)
• Ticks (for controlling execution of forks)
• User management functions
• etc.

In some sense the MOO Programming language can be compared to an operation system. A server manages users and programs in somewhat similar way.