Xz — A General-Purpose Language for the AI-Writing Era

Xz is a general-purpose programming language designed around a single thesis:

AI-written, Human-reviewed.

Code will increasingly be written by AI. Xz is built so that humans can read, verify, and trust machine-generated code — by making every behavior explicit, every contract visible, and every failure path typed.

Design pillars

Pillar	Choice
Philosophy	AI-written, Human-reviewed
Type system	Strong static typing; explicit types at contract boundaries, local inference inside bodies
Memory model	Value semantics; immutable by default, explicit mut
Syntax	Python-like; brace-delimited blocks, indentation layout
Execution	Compiled to native binaries via LLVM
Concurrency	Structured concurrency (async/await) + typed channels
Error handling	Result types on a single explicit error channel (no exceptions)
Intent verification	"No unverified claims" — @intent/@ensures/@effects checked against code, @trusted escape hatch
Interoperability	FFI-first: C ABI bridge, generated Python bindings (xz bind)
Compiler feedback	Structured JSON diagnostics designed for LLM self-correction

Repository layout

Xz/
├── README.md               # This overview
├── examples/               # Design-validation programs (not runnable yet)
└── docs/
    ├── 01-philosophy.md    # Core thesis and design principles
    ├── 02-syntax.md        # Language syntax (Python-like)
    ├── 03-type-system.md   # Strong static types, contract-point explicitness
    ├── 04-memory-model.md  # Value semantics, explicit mutation
    ├── 05-concurrency.md   # Structured concurrency + typed channels
    ├── 06-error-handling.md# Result types, single error channel
    ├── 07-compiler.md      # LLVM backend, JSON diagnostics
    ├── 08-roadmap.md       # Implementation roadmap
    ├── 09-intent-verification.md  # Comment–code contract checking (differentiator)
    ├── 10-ffi-interop.md    # C ABI bridge + Python bindings (ecosystem survival)
    ├── 11-grammar.md       # Full grammar: lexical, precedence, EBNF (authoritative)
    └── 12-stdlib.md        # Minimum stdlib surface (collections/network: Phase 7)

Status

Phases 1–4 implemented. The front end (xz check) and the LLVM JIT backend (xz run) work; hello.xz and contracts.xz execute. Phases 5–8 (FFI, concurrency runtime, stdlib, tooling) are on the docs/08-roadmap.md. The backend uses a root-free portable LLVM 17 (see docs/13-codegen.md).