HAL/S - Goals and Principles

Goals and Principles

The three key principles in designing the language were reliability, efficiency, and machine-independence. The language is designed to allow aerospace-related tasks (such as vector/matrix arithmetic) to be accomplished in a way that is easily understandable by people who have spaceflight knowledge, but may not necessarily have proficiency with computer programming.

HAL/S was designed not to include some constructs that are thought to be the cause of errors. For instance, there is no support for dynamic memory allocation. The language provides special support for real-time execution environments.

Some features, such as "GOTO" were provided chiefly to ease mechanical translations from other languages.

On the Preface page of the HAL/S Language Specification, it says,

fundamental contributions to the concept and implementation of MAC were made by Dr. J. Halcombe Laning of the Draper Laboratory.

"HAL" was suggested as the name of the new language by Ed Copps, a founding director of Intermetrics, to honor Hal Laning, a colleague at MIT.

A proposal for a NASA standard ground-based version of HAL named HAL/G for "ground" was proposed, but the coming emergence of the soon to be named Ada programming language contributed to Intermetrics' lack of interest in continuing this work. Instead, Intermetrics would place emphasis on what would be the "Red" finalist which would not be selected.