CLOJURE/CONJ 2026

Smuggling Clojure into Statically Compiled Video Games

Smuggling Clojure
into Statically Compiled
Video Games

With Silk by Lotus Mundi

James J. Tolton · Clojure/Conj 2026

PRIOR ART · 2016

Let’s play Minecraft/Doom/StarCraft!

The open letter to Udacity CEO Sebastian Thrun proposing the Game Agent AI Project

Closing of the letter and the December 1, 2016 update

Open letter to Udacity CEO Sebastian Thrun · December 1, 2016 · ipetitions.com/petition/gameagentaind

The demos

DEMO · REFLEX AGENT

Silk x Doom

REFLEX AGENT

Silk x Doom

DEMO · GOAL-BASED AGENT

Silk x Project Zomboid

GOAL-BASED AGENT · HTN + PRIORITY TABLE

Silk x Project Zomboid

DEMO · GOAL-BASED AGENT

Silk x Factorio

GOAL-BASED AGENT · RECIPE HTN + GOAL LADDER

Silk x Factorio

DEMO · SEVERAL WORLDS

Silk the Dark Lord

ONE REPL · SEVERAL WORLDS

Silk the Dark Lord

Introducing Silk

By Lotus Mundi

SILK BY LOTUS MUNDI

Any game. Any game engine. Anywhere.

Ariel, the Silk aerialist — Art by Mayteesk

PRIOR ART

The Silk Road (part 1)

1989

2014

2015

2016

2017

Bracket

2018

The Dragon Book: Compilers, Principles, Techniques, and Tools

2019

2020–21

2021

2023

2024

Paradigms of Artificial Intelligence Programming

2025

2026

FROM THE GIT HISTORY

The Silk Road (part 2)

SILK BY LOTUS MUNDI

The Three Pillars

CLOJURE

A (love) language

SILK OTP

A composition language

SILK TENSORS

A tensor language

THE LANGUAGE + THE RUNTIME

What did I just see?

Silk

C#

Unity IL2CPP

JVM

Clojure

Lua 5.2–5.4

JS

JavaScript

C

ESP32

Project

MyGame/Assets/
├── Scripts/Combat.cs
└── Silk~/game/combat.silk

SILK TIER LIST

Currently supported hosts

As of October 2, 2026

S

A

JVM

5.2

5.3

5.4

B

C

Kahlua

F

ESP32

HOW SILK ENTERS A SYSTEM

6 Modes of integration

CLI

silk run game/server.silk

Static artifact

silk compile <target> -o <dst>
./<dst>

Embedded evaluator

_vm.Eval("(require 'game.combat)");

Bound function

var damage = _vm.Resolve(
    Sym.Ns("game.combat"),
    Sym.Name("damage"));
damage.Invoke(30L, 10L);

Ports

var output = _vm.OpenPort(
    SilkRT.Kw("t04", "out"));
foreach (var msg in output.Drain())
    Handle(msg);

Distribution peer

silk node --name game@host \
  --cookie demo app.silk

BINDING TIME

Three compilation binding times

0

0-SHOT

Interpret / JIT

At evaluation

1

1-SHOT

Sealed / sovereign

One artifact

MANY-SHOT

Delegated toolchain

Unity · downstream builds

SILK BY LOTUS MUNDI

Continuous Delivery and Testing

01 · Unit testing

345 suites written for Silk test the language, runtime and standard library with clojure.test: 11,958 assertions, run on every backend. 142 xUnit tests cover the .NET host.

02 · Oracle testing

Silk’s results are compared with those of a reference implementation, namely real Clojure under Babashka and stock Erlang/OTP. J is a second reference for APL questions. A deliberate difference is recorded as a divergence.

03 · Divergent oracle testing

Hosts and backends are checked against each other. A compiled program must reproduce the interpreter’s output exactly, the HLSL that ships is checked against the CPU run, and every tensor run is judged for backend parity.

04 · Property-based testing

OTP invariants are stated as properties and checked on generated inputs, with stock Erlang/OTP as the reference. The suites run continuously.

05 · Fuzz testing

Fuzz scenarios are generated from a seed and can be replayed. A long-running soak process re-runs each failure to confirm it and records the seed that reproduces it. Since June, 756 soak campaigns have run.

06 · Conformance testing

83 suites ported from Clojure’s own test tree run against Silk, and all pass. A test marked as expected to fail that starts passing fails the build until the mark is removed.

07 · Presentation testing

A Scryer Prolog grammar enumerates 93,855 tensor programs from a formal presentation of the language. Each is judged against Dyalog APL, and none fails; no LLM writes or selects cases.

08 · Acceptance testing

Language behavior is first specified as executable acceptance tests in Farley’s four-layer style, before the runtime implements it. A lint fails the build if a host term leaks into the upper layers.

09 · System testing

Every product and application is itself a test: each game, mod, tutorial, IDE integration and manual example. Unity play-mode tests start a real Erlang node and check its output.

10 · Static analysis

Linters and static checks run in the fast gate. silk fmt --check rejects unformatted code, and the editor warns on any definition that cannot run on the strict profile.

428conformance suites

11,958assertions per backend

~94ktensor programs per backend

36CI lanes; a red trunk blocks push

~½ millionchecks per pipeline run (order of magnitude)

Five questions

THE FIVE QUESTIONS

1. How do I get my code “in” to the game??

THE FIVE QUESTIONS

2. O god, what have I done?

Choosing a programming paradigm

Francisco Goya, Saturn Devouring His Son (1819–1823), Museo del Prado

THE FIVE QUESTIONS

3. How do I stop the bleeding?

An immutable language in a mutable world

Jean-Louis-César Lair, The Torture of Prometheus (1819)

THE FIVE QUESTIONS

4. What was even the point?

Solving the hardest problem in game systems design

THE FIVE QUESTIONS

5. You’re asking the wrong question.

How do we keep the wheels from falling off this thing? Also…

1. How do I get my code “in” to the game??

Into the game loop

INTO THE GAME LOOP

Game loop and object lifetime

Jay’s low-poly dinosaur with a photo-textured face

Unity

GameObject

MonoBehaviour components

Unreal

AActor

UActorComponent

Godot

Node

Scripts on a node tree

s&box

GameObject

C# components

GAME DEVELOPMENT CHALLENGES

Scenes

Reusable modular dungeon pieces arranged separately — **Reusable definition**
Prefab / Blueprint

Instantiate→

Dungeon pieces assembled into a lit scene — **Scene · Objects + state**
Instances · A place in the world

Unity

Scenes + prefabs

Unreal

Levels + Blueprints

Godot

Nested scenes

s&box

Scenes + prefabs

GAMES + THEIR ECOSYSTEMS

Languages and Platforms

Factorio

C++ engine · Lua mods

Project Zomboid

Java · Kahlua

RimWorld

C# · Unity · Harmony

Stardew Valley

C# · MonoGame · SMAPI

Baldur’s Gate 3

Osiris · Lua via Script Extender

Doom / ManagedDoom

Original C · C# port

VIDEO GAME DEVELOPMENT

The Unity Editor

VIDEO GAME DEVELOPMENT

The loading screen

THE LANGUAGE + THE RUNTIME

The compilation pipeline

Silk

C#

Unity IL2CPP

JVM

Clojure

Lua 5.2–5.4

JS

JavaScript

C

ESP32

2. O god, what have I done?

The WASM model

DEFINE IT

Silk in a Unity project

combat.silk

(ns game.combat)
(defn damage [hp amount]
  (- hp amount))

Combat.cs · component members

private ISilkGameVm _vm;
private ISilkFn _damage;

void Awake()
{
    _vm = SilkVm.Attach(
        () => (long)(Time.fixedTime * 1000));
    _vm.Eval("(require 'game.combat)");
    _damage = _vm.Resolve(
        Sym.Ns("game.combat"),
        Sym.Name("damage"));
}

object Attack()
    => _damage.Invoke(30L, 10L); // 20

THE WASM MODEL

Interface Definition Language

C# provider

[SilkHostFn("t02.log", "info",
    Doc = "Write to the Unity console.",
    Capability = ":t02/log")]
internal static void Info(string msg)
    => Debug.Log(msg);

Silk caller

(ns t02.app
  (:require [t02.log]))

(defn greeting [] "hello from t02")

(defn hello! []
  (t02.log/info (greeting)))

Lua provider

return function(rt)
  return {
    pack = "course/t02-log",
    provides = {"t02/log"},
    host_fns = {
      ["t02.log/info"] = function(msg)
        print(msg)
      end,
    },
  }
end

3. How do I stop the bleeding?

???

THE FIVE QUESTIONS

3. How do I stop the bleeding?

An immutable language in a mutable world

4. What was even the point?

OTP

VIDEO GAMES

The central problem of video games

Going from simple to easy

PLAYER → SKELETON

Direct coupling

PlayerCombat.cs + Skeleton.cs

public sealed class PlayerCombat : MonoBehaviour
{
    [SerializeField] Skeleton target;
    public void Attack() => target.TakeDamage(10);
}

public sealed class Skeleton : MonoBehaviour
{
    [SerializeField] int hitPoints = 30;
    public void TakeDamage(int amount)
    {
        hitPoints -= amount;
        if (hitPoints <= 0) Destroy(gameObject);
    }
}

TRADITIONAL METHODS

Ways to connect game systems

REFERENCES

Direct references
Singletons
The God Object
Game manager
Service locator
Dependency injection
Mediator

CALLBACKS + EVENTS

Callbacks
Delegates
Observer pattern
Event bus
UnityEvents
Godot signals
ScriptableObject channels
Message queues

STATE + DATA

Database (you wish!)
“Declarative” state
ECS / DOTS
Event log / CQRS
Event sourcing
Blackboards
Redux-style stores
view = f(data)

CONTROL FLOW

State machines
Behavior trees
Coroutines
async / await
FRP / Rx streams (RxJS, UniRx)
xforms / transducers
Command pattern
Job system

LANGUAGE TRICKS

Frameworks
Bespoke engines
Macros
Generics
Multimethods
Monads
The functional dream
etc…

Who owns state, order, and lifetime?

GOAL-BASED AGENT · NSGA-II + LAYOUT ENGINE + PATH ROUTER

Languages limit modern game AI

Silk x RimWorld: arbiter, NSGA-II generator, layout engine with path router and wall planner, build planner, supervisor, executor and actuator, all supervised Silk OTP stages inside the game process

Colony Optimizer dashboard: demand radar, convergence, champion base, execution log

Colony Optimizer · Silk × UI Toolkit: demand radar, convergence, champion base, orders in flight

Commonality/Variability Analysis

THE PROBLEM DECOMPLECTED · 1

The Angel’s Sandwich

THE PROBLEM DECOMPLECTED · 2

The Devil’s Candycane

THE PROBLEM DECOMPLECTED · 3

The Devil’s Christmas Tree

SILK OTP

The CENTRAL problem, revisited

OTP

Erlang inverts the sandwich

SILK OTP

From Christmas Tree to Data Donut

THE THREE PILLARS

Silk OTP

○ SILK OTP

A composition language

SILK OTP

Inside a Skeleton actor

skeleton.silk

(actor/spawn
  (fn skeleton [ui-manager-pid]
    (loop [state {:hp 30}]
      (let [state (handle state (actor/receive!))]
        (actor/send! ui-manager-pid {:hp (:hp state)})
        (recur state))))
  ui-manager-pid)

SILK OTP · GEN_SERVER

The actual OTP protocol

Callbacks · silk.otp.gen → gen · silk.otp.result → r

(defrecord Counter []
  gen/IGenServer
  (gen-init [_ _ [n]] (r/=>Ok n))
  (handle-call [_ _ _ _ n] (r/=>Reply n n))
  (handle-cast [_ _ delta n]
    (r/=>NoReply (+ n delta)))
  (handle-info [_ _ _ n] (r/=>NoReply n))
  (handle-continue [_ _ _ n] (r/=>NoReply n))
  (terminate [_ _ _ _] nil))

Client functions · callers never cast or call directly

;; client API: the only surface a caller sees
(defn start-link [parent n]
  (gen/start-link parent (->Counter) [n]))

(defn add! [counter delta]
  (gen/cast counter delta))

(defn value [counter]
  (gen/call counter :read 3000))

;; a caller
(let [c (start-link parent 40)]
  (add! c 2)
  (value c))        ;; => 42

State in → tagged result out · the client functions do the cast and the call

SILK OTP · GEN_STATEM

State + event → transition + actions

IStateMachine callback · silk.otp.statem.result → sr

(handle-event [_ _ _ event state data]
  (case [state event]
    [:saving :destination-ready]
    (sr/=>KeepState data [(sr/=>Postpone)])

    [:saving :source-saved]
    (sr/=>NextState :joining data)

    [:joining :destination-ready]
    (sr/=>NextState :playing data)

    (sr/=>KeepState data)))

Client functions · silk.otp.statem → statem

;; client API over the state machine
(defn start-link [node]
  (statem/start-link node (->Transfer) false []))

(defn destination-ready! [t]
  (gen/cast t :destination-ready))

(defn source-saved! [t]
  (gen/cast t :source-saved))

(defn state [t]
  (gen/call t :read 3000))

;; a caller
(destination-ready! t)   (state t) ;; => :saving
(source-saved! t)        (state t) ;; => :playing

The early :destination-ready is postponed in :saving and replayed after :source-saved

SILK OTP · SUPERVISOR

Supervision tree

SILK OTP · WHY RESTARTING WORKS

Let it crash

Why restarting works: ease of finding bugs in production. Core feature: repeatable easy, transient hard. Secondary feature: repeatable easy, often overlooked; transient hard.

Bugs that happen in production. Core feature: repeatable should never, transient all the time. Secondary feature: repeatable pretty often, transient all the time.

Bugs handled by restarts. Core feature: repeatable no, transient yes. Secondary feature: repeatable depends, transient yes.

Fred Hébert, “The Zen of Erlang,” ferd.ca, February 8, 2016 · repeatable = Bohrbugs, transient = Heisenbugs (Jim Gray, 1985)

A LANGUAGE THAT FITS THE PROBLEM

Sending messages

ADD AN ARROW · ADD A SYSTEM

Changing the message topology

CIRCLES + ARROWS

Systemic game design

ERLANG DISTRIBUTION PEER

Actors across machines

3. How do I stop the bleeding?

Ports

SILK OTP

The game loop meets Silk OTP

C# · Unity component excerpt

void Awake()
{
    _vm = SilkVm.Attach(
        () => (long)(Time.fixedTime * 1000));
    _out = _vm.OpenPort(SilkRT.Kw("t04", "out"));
    _vm.Resolve(Sym.Ns("t04.app"),
                Sym.Name("start!")).Invoke();
}

void Update()
{
    _vm.StepFor(stepBudgetMs, stepChunkTurns);
    foreach (var msg in _out.Drain())
        HandleGameEffect(msg);
}

GAME + HEADLESS TEST

One simulation, two environments

SILK OTP

New methods of storytelling

5. Do you even Lisp, bro?

PRIOR ART · 2025

Language, Weaponized

Modern Software Engineering

Continuous Delivery by Jez Humble and David Farley

David Farley, Modern Software Engineering (2021) · Humble & Farley, Continuous Delivery (2010) · the MSE channel on YouTube

PRIOR ART · 2024

Paradigms of Artificial Intelligence Programming

This is an open-source repository for the book Paradigms of Artificial Intelligence Programming by Peter Norvig

PAIP Chapter 5, ELIZA: Dialog with a Machine

Peter Norvig, Paradigms of Artificial Intelligence Programming (1992) · github.com/norvig/paip-lisp

PRIOR ART · 2024

The Power of Prolog

GitHub mthom/scryer-prolog: a modern Prolog implementation written mostly in Rust

Scryer Prolog aims to become to ISO Prolog what GHC is to Haskell

GitHub jjtolton/libscryer-clj: Clojure bindings for Scryer Prolog

libscryer-clj README: the lisp and prolog epic handshake

Markus Triska, The Power of Prolog · metalevel.at/prolog · youtube.com/@ThePowerOfProlog · Scryer Prolog · libscryer-clj

THE THREE PILLARS

Clojure

♡ CLOJURE

A (love) language

LOTUS MUNDI

What’s next?

Lilinaut in Rider: stopped at a breakpoint in app.silk while Unity is in play mode

Lilinaut in Rider: stopped at a breakpoint in app.silk inside a built Unity player

Silk Taps: inline results and a value inspector

ToolingLilinaut: a Rider debugger for Silk, in Unity play mode and in built players. Taps show inline results.
DistributionPackages and binaries.
Battle testing
DocumentationLanguage, runtime, host APIs.
Tutorials
Marketing

LOTUS MUNDI

Silk by Lotus Mundi

Still from Bad Apple on Doom on RimWorld

Dream with us.