Notation

The symbol catalog

A small, stable set of overlays. ASCII is canonical; a Unicode display form (Σ, ∈, ⇒) projects on top.

EML / Py⁺MeaningStatus
x^+100init if undeclared, else add-assignimplemented
x^0outputimplemented
x^-5 x^*2 x^/2augmented assignimplemented
Σ(i^2, i in [1:N])summation over an inclusive rangeimplemented
i in [1:10]inclusive range / membershipimplemented
x > 40 ? A : Bconditional expressionimplemented
x and y x or y not xshort-circuit and/or, unary notimplemented
f(x) => ycall + bindimplemented
<M>(data) m^Tmatrix construct / transpose (round-trips too)implemented
list^+[1,2,3]list literalimplemented
def f(...): ...function definition (round-trips, except @hot — see below)implemented
@cold @hotcold/hot separation — @hot is a permanent, comment-only round-trip exceptionimplemented
@temporal_loop(...)time loop, no busy-wait; forward-onlypartial

This is a compact, hand-picked slice of the full registry (eml-symbols.json), grouped by syntax family with an implementation-status label — implemented, partial, conceptual, or planned. Full self-contained AI-semantic spec (status vocabulary, twelve-loop taxonomy, bug/repair/criticality models)

The twelve-loop semantic taxonomy

EML classifies loops by intent and dynamics, not only by surface keyword — a plain while can be several of these classes. Only 5 of the 12 classes have accepted surface syntax today; the rest are conceptual.

IDLoop classStatus
L1Basic repetitionpartial
L2Conditional looppartial
L3Algebraic looppartial
L4Event loopconceptual
L5Convergent loopconceptual
L6Recursive looppartial
L7Fractal loopconceptual
L8Quantum loopconceptual
L9Chaotic loopconceptual
L10Spiral loopconceptual
L11Evolutionary loopconceptual
L12Temporal looppartial
Command line

A real toolchain

The eml CLI runs the whole pipeline from source — parse, transpile, execute, trace, classify, round-trip.

$ eml run f.emltranspile and execute via Python
$ eml transpile f.eml --target cppEML → Python, or the C⁺⁺⁺ prototype
$ eml trace f.eml --runeml-trace-v1 trace; bakes in an interp≡Python check
$ eml compress f.pyreverse: Python (subset) → EML
$ eml roundtrip f.emlEML → Py → EML → Py fixpoint check
$ eml bugs f.eml --runclassify errors (5 levels), mapped to source
Architecture

Small packages, no cycles, run from source

A TypeScript monorepo. The parser, transpiler and interpreter are browser-safe — which is exactly why the playground above runs with no backend.

@eml/parsernormalize → lex → parse → AST
@eml/transpiler-pythonsemantic analysis + Python emitter
@eml/transpiler-emlreverse + round-trip validators
@eml/transpiler-cppC⁺⁺⁺ prototype back end
@eml/interpexecution-truth interpreter + trace
@eml/traceeml-trace-v1 emitter
@eml/bug-classifier5-level BUG classifier
@eml/clithe eml command

No LLM in the core transpilation chain. Determinism and round-trip faithfulness are invariants, not features.

License & patent

Open source, under Apache-2.0

EML is free to use, study, modify, and build on — commercial use included. Keep the attribution, credit the original author, and the rest is yours.

Open source (Apache-2.0)

The whole project is released under the Apache License 2.0 — use it, fork it, ship products with it.

Just credit the author

Keep the license/attribution notices and respect Neo.K (許筌崴) / EveMissLab as the original author. That is the only ask beyond the license.

Patent — granted to you

Aspects are covered by Taiwan Utility Model M672933 (Taiwan only). Apache-2.0 includes a patent-license grant, so you are covered — and some concepts already reach beyond the patent.

Contributions welcome

Inbound contributions are under the same Apache-2.0 terms (inbound = outbound). No separate CLA.

Built in the open. Commercial use, forks, and adaptations are all welcome under Apache-2.0.

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