Prowl

Prowl is a typed concatenative logic language with many ideas imported from functional programming and abstract algebra. It is still deeply in the design and development phase, though implementations and design documents from various points in the past exist.

The main (planned) features of Prowl are:

• A static type system based on rank 2 type inference
• Dataflow operators with inference based on monoid unification
• A determinism system based on boolean unification
• A costack-of-stacks as the base datastructure
• Regex-inspired nondeterministic control flow based on relation algebra
• Equational Datatypes based on Zhegalkin polynomials
• A runtime with constraint logic programming to support nondeterministic guesses, abelian group arithmetic, set arithmetic, catenable deques, and datatype traversals.