What is refal?

Refal is a programming language that stands for "REcursive Functions Algorithmic Language." It was developed in the early 1970s by a group of Russian computer scientists led by Valentin Turchin. Refal is a high-level, functional programming language designed for writing algorithms, data structure manipulation, and symbolic computations.

Refal's syntax is similar to Lisp, with a focus on functions as data structures. It also supports pattern matching, which allows developers to match input data structures against predefined patterns and algorithms. Refal features a strong type system that ensures type safety and prevents runtime errors.

Refal is considered a research language and is not widely used in commercial applications. However, it has been used for various research purposes, including artificial intelligence, natural language processing, and computer science education.

Overall, Refal is a unique programming language that offers advanced functionality and expressiveness for algorithmic design. It represents an important contribution to the field of computer science, and its ideas have influenced the development of other programming languages.