Lumbda names a Lisp/Scheme-derived language carrying four independently implemented execution backends — one surface syntax, one test suite. A Python tree-walker with an optional bytecode VM, a C implementation that adds an x86_64 JIT, and a pure x86_64 GNU asm interpreter (~6,600 lines, ~23 KB stripped, zero external dependencies). Every backend runs a shared .lsp source byte-identically, with full first-class continuations, exact rationals, records, and hygienic macros.
Get it
git clone https://git.unturf.com/engineering/unturf/lumbda.git
cd lumbda
make test-allRun a program in any tier:
python3 lumbda.py --fast examples/fibonacci.lsp
./c/lumbda examples/fibonacci.lsp
./asm/lumbda < examples/fibonacci.lspFour tiers, one language
| Tier | Lines | Binary | What a tier buys |
|---|---|---|---|
| Python interpreter + bytecode VM | 3,743 | — | REPL hackability, debugging, reference |
| C tree-walker + bytecode VM | 9,164 | ~215 KB | deep recursion, production workloads |
| C + x86_64 JIT | +patches | ~215 KB | 7–10× faster than CPython on recursive workloads |
| Pure x86_64 GNU asm | 6,645 | ~23 KB | zero-dependency boot, auditability, embedded |
| GNU asm + naive mark-sweep GC + meta-GC arena | (same source, GC_NAIVE=1) | ~27 KB | bounded memory without manual arena discipline |
Portal: feedback across time
A continuation carries feedback within a process. A portal carries feedback across processes. Same primitive, different scope: capture machine state, serialize, reload elsewhere, resume. Lumbda ships three portal formats with distinct trade-offs:
- S-expression portal — Scheme source as a wire protocol. 16 of 16 producer×consumer cells green across Python, C, asm no-GC, and asm GC.
- JSON portal — graph-aware, preserves closures and live continuations (Python, C).
- Binary heap dump — asm only. 1.5 ms save+resume between two processes.
EML universality proof
A single operator eml(x, y) = exp(x) − ln(y) with a constant 1 generates all elementary functions: exp, ln, arithmetic, negation, complex-plane access, trigonometry. Verified numerically in Python, verified in Lumbda's own bytecode, proven formally in Lean 4 with zero sorry. Lumbda's native symbolic-rewrite checker runs five theorems in 46 ms cold or 7 ms cached — roughly 16× faster than Lean's cold rebuild on identical hardware.
Whitepaper
Full language reference, tier-by-tier architecture, benchmarks, meta-GC design, universality proof.
License
AGPL-3.0-only. Public domain for whitepapers, proofs, and disclosures through undefect.com. Companion to unturf.com’s permacomputer project.