Project Story & Motivation

Relevant source files

The following files were used as context for generating this wiki page:

• README.md
• jazz-next/README.md
• AGENTS.md
• scripts/check-spec-authority.sh
• scripts/check-docs.sh
• jazz2/package.yaml
• jazz-hs/package.yaml

Jazz is a functional programming language designed to bridge the gap between the expressive power of languages like Haskell and the accessibility of languages like Elixir. The project focuses on providing a strong, statically typed environment with type inference, while deliberately avoiding the complex category theory terminology (e.g., Monads, Semigroupoids) that often presents a barrier to entry for beginners. Instead, Jazz adopts a standard approach to typeclasses using intuitive categories such as Collection and Orderable.

Sources: README.md:1-10, jazz2/package.yaml:1-20

Vision and Core Philosophy

The primary motivation behind Jazz is to create a functional language that is "easy to understand" in terms of syntax and type systems. It emphasizes immutability, currying by default, and a clear distinction between pure and impure functions.

Key Conceptual Pillars

• Accessible Type System: Replacing abstract category theory concepts with human-readable typeclasses.
• Safety by Default: Strong static typing and explicit markers (!) for impure functions.
• Modern Functional Features: First-class functions, partial application, and robust type inference.

Sources: README.md:5-25, README.md:95-105

Language Evolution and Workspace Architecture

The Jazz project has undergone significant structural transitions to manage its evolution from experimental sketches to a verified compiler implementation. The repository is partitioned into distinct workspaces, each representing a different stage of the project's lifecycle.

The following diagram illustrates the relationship between the different compiler iterations and their authoritative status within the project.

Workspace Definition

Workspace	Status	Role
jazz-next/	Active	The primary target for new compiler implementation work including the analyzer, parser, and type inference.
jazz-hs/	Legacy	Read-only historical reference code. Originally used as an implementation baseline.
jazz2/	Legacy	Reference-only design source for future ideas; non-normative for current behavior.

Sources: jazz-next/README.md:3-10, AGENTS.md:3-15, scripts/check-spec-authority.sh:30-40

Feature Implementation Status

The project tracks its progress through a "verified" subset of features currently operational in the jazz-next path versus aspirational goals.

Implemented Today (Verified)

• Core Expression Subset: Strong, static typing and type inference are fully operational for core expressions.
• Function Semantics: Functions are first-class citizens and are curried by default.
• Purity Enforcement: Stub enforcement prevents direct calls to impure functions (denoted by !) within pure binding bodies.
• Runtime Helpers: A bundled prelude provides standard functions like map, filter, hd, tl, and print!.

Sources: README.md:12-25, jazz-next/README.md:15-25

Planned and Aspirational Features

The roadmap includes advanced language features and performance targets:

• Algebraic Data Types (ADTs): End-to-end runtime and compiler behavior for ADTs.
• Pattern Matching: Full implementation across the compiler and runtime.
• LLVM Backend: Targeting LLVM for high-performance execution (evidenced by the inclusion of llvm-hs dependencies in legacy and local-dependency paths).
• Module System: Full semantics for module loading and imports.

Sources: README.md:27-35, jazz-hs/package.yaml:20-35

Repository Governance

The project maintains strict governance via automated scripts to ensure that documentation and implementation remain synchronized. Semantic changes to the language require a Formal Decision Record or RFC before implementation.

Conclusion

The Jazz project is motivated by a desire to provide a functional language that prioritizes developer experience and clarity without sacrificing the safety of static typing. By organizing the repository into a clear hierarchy—moving from legacy prototypes (jazz-hs, jazz2) to a modern, verified compiler (jazz-next)—the project maintains a clear path toward its aspirational goals of a high-performance, LLVM-backed functional environment.

Sources: README.md:1-50, jazz-next/README.md:1-15