Eagle | Craft Javascript Runtime

const char* script = "console.log('Hello from Eagle Craft');"; ec_value_t result = ec_run_string(ctx, script, "<main>");

#include "eagle_craft.h" int main() ec_runtime_t* rt = ec_runtime_new(1024 * 1024); // 1MB heap ec_context_t* ctx = ec_context_new(rt);

1. Overview Eagle Craft JavaScript Runtime (ECJR) is a lightweight, standalone JavaScript runtime environment designed for embedded systems, game scripting, and edge computing. Unlike traditional runtimes such as Node.js or Deno, which are built on V8 (Chrome’s high-performance engine), ECJR is built from the ground up with a focus on small memory footprint , deterministic execution , and easy embeddability into C/C++ or Rust applications. eagle craft javascript runtime

"name": "my-sensor-script", "target": "eagle-craft", "memory": "128KB", "entry": "main.js", "dependencies": "@eagle-craft/gpio": "^1.0.0"

if (ec_is_error(result)) const char* err = ec_stringify(ctx, result); fprintf(stderr, "Error: %s\n", err); const char* script = "console

ECJR implements a subset of ECMAScript 2023 (ES14) and provides a modular, event-driven architecture without the overhead of a just-in-time (JIT) compiler. It is ideal for microcontrollers (ARM Cortex-M, RISC-V), game modding, IoT devices, and plugin systems for desktop applications. 2.1 Bytecode Virtual Machine ECJR uses a register-based bytecode VM, similar to LuaJIT but optimized for JavaScript’s dynamic semantics. Source code is parsed into a compact intermediate representation (IR) and then compiled to bytecode. Execution is strictly stackless, with each coroutine maintaining its own call stack. 2.2 Garbage Collection A tri-color, incremental, mark-and-sweep garbage collector runs with configurable pause times (default 2ms per 16ms frame). It supports weak references and finalizers, making it suitable for real-time systems. 2.3 No JIT, No Parse/Bytecode Cache To ensure predictable performance and low latency, ECJR deliberately omits a JIT compiler. All code is either interpreted directly from bytecode or optionally AOT-compiled to native code via a separate tool ( eagle-craft aot ). Bytecode can be serialized to disk to avoid re-parsing. 3. Key Features | Feature | Support | |--------------------------|----------------------------------------| | ES2023 standard library | Partial (Array, Object, Map, Set, Promise, Proxy) | | async / await | Full (cooperative multitasking) | | Modules (ESM) | Yes, with custom resolver hooks | | setTimeout / setInterval | Yes, via embedded event loop | | console API | Yes (log, error, warn, time, assert) | | fetch | Optional (requires network plugin) | | fs / os | Provided via host bindings only | | WebAssembly | No (future roadmap) | | eval and Function | Restricted (off by default) | 4. Embedding API (C) ECJR provides a simple C API for embedding:

ec_context_free(ctx); ec_runtime_free(rt); return 0; Source code is parsed into a compact intermediate

Eagle Craft JavaScript Runtime fills a critical gap between heavyweight JS engines (V8, JavaScriptCore) and minimal scripting languages (Lua, MicroPython). It brings the familiarity of JavaScript to resource-constrained environments without sacrificing safety or embeddability. For developers building IoT devices, game modding frameworks, or plugin systems, ECJR offers a pragmatic, performant, and sandboxed solution.

Example package.json for an embedded project: