The Howdy Glossary

SISAL is a single-assignment programming language emphasizing implicit parallelism, developed in the mid-1980s by institutions including the University of Manchester and Caltech. It ensures variables are assigned once, allowing safe parallel execution without race conditions common in imperative languages. Utilizing dataflow analysis tools like streams for fine-grain concurrency, SISAL serves as a model for future languages by showcasing efficient parallelism through high-level constructs while permitting control over lower-level aspects when needed.

Competitors to SISAL in implicit parallelism and safe execution include Erlang, Haskell, and Concurrent ML. These languages also emphasize parallel processing and functional paradigms but differ significantly: Erlang focuses on fault-tolerant distributed systems; Haskell employs lazy evaluation within functional programming; Concurrent ML specializes in concurrent programming with message-passing constructs. They offer diverse approaches catering to developers' varying needs beyond what SISAL provides with its unique emphasis on single assignment and fine-grain concurrency.

SISAL's distinctive advantage lies in its approach to implicit parallelism via single assignment, ensuring safe execution without race conditions or shared memory issues. Its dataflow analysis tools enable efficient fine-grain concurrency management, making it a pioneering language for handling parallel processing through high-level constructs while maintaining the ability to manage low-level details as necessary. This blend of features distinguishes SISAL from its competitors and positions it as an influential model for leveraging robust parallel processing support in subsequent programming languages.