In this article, we are going to analyze MultiLisp and all its relevant aspects in depth. MultiLisp is a topic of great importance today, since it has a significant impact on society, the economy, culture, and many other areas. Over the years, MultiLisp has generated constant debate and has sparked growing interest in different sectors. In this regard, it is crucial to fully understand the nature and scope of MultiLisp, as well as its short- and long-term implications. Therefore, this article aims to offer a comprehensive and detailed view on MultiLisp, with the aim of enriching knowledge and promoting a constructive debate around this topic of global relevance.
| MultiLisp | |
|---|---|
| Paradigms | Multi-paradigm: functional, imperative, concurrent, meta |
| Family | Lisp |
| Designed by | Robert H. Halstead Jr. |
| Developer | Massachusetts Institute of Technology (MIT |
| First appeared | 1980 |
| Typing discipline | Dynamic, latent, strong |
| Scope | Lexical |
| Implementation language | Interlisp |
| Platform | Concert multiprocessor |
| License | Proprietary |
| Influenced by | |
| Lisp, Scheme | |
| Influenced | |
| Gambit, Interlisp-VAX | |
MultiLisp is a functional programming language, a dialect of the language Lisp, and of its dialect Scheme, extended with constructs for parallel computing execution and shared memory. These extensions involve side effects, rendering MultiLisp nondeterministic. Along with its parallel-programming extensions, MultiLisp also had some unusual garbage collection and task scheduling algorithms. Like Scheme, MultiLisp was optimized for symbolic computing. Unlike some parallel programming languages, MultiLisp incorporated constructs for causing side effects and for explicitly introducing parallelism.
It was designed by Robert H. Halstead Jr., in the early 1980s for use on the 32-processor Concert multiprocessor then being developed at Massachusetts Institute of Technology (MIT) and implemented in Interlisp. It influenced the development of the Scheme dialects Gambit,[1] and Interlisp-VAX.
MultiLisp achieves parallelism with the PCALL macro, where
(PCALL Fun A B C ...)
is equivalent to
(Fun A B C ...)
except that the arguments A, B, C, etc. are explicitly allowed to be evaluated in parallel; this circumvents the usual order of evaluation, which is sequential and left to right. It also makes use of a parallel programming construct called futures, which resembles forking, combined with lazy evaluation. Using this construct, an expression such as
(cons (FUTURE A) (FUTURE B))
can be written, which will overlap the evaluation of the expressions A and B, not only with each other, but with computations that use the result of the cons call, until an operation is performed that needs correct information about the value of A or B.