Rust and browser WASM APIs#

The engine is a Cargo workspace with no Node.js or npm requirement. Rust libraries and browser WebAssembly replace the former Node/TypeScript entry points.

1use laymesh_core::engine::compile_file;2let scene = compile_file("figure.lay")?;3let svg = laymesh_render::render_svg(&scene)?;

use laymesh_core::engine::compile_file;
let scene = compile_file("figure.lay")?;
let svg = laymesh_render::render_svg(&scene)?;

For in-memory sources, call compile_source(source, filename, Host) and supply resources in Host.files. Native rendering discovers system fonts; WASM uses user-loaded fonts only. Browser bindings expose render(source, filename, files_json) and language_query(files_json, filename, method, offset, locale); language offsets use UTF-16. Both targets share parser, layout, font handling, and SVG rendering.

Python and Jupyter retain their public interfaces and invoke the native executable. LAYMESH_CLI overrides the native binary for development.

workflow#

Complete sources and executable verification fixtures for this workflow are listed in the feature coverage map. Follow this page’s input conditions and limits when composing features.

Using Node with the native CLI#

The former TypeScript package is removed. Node can invoke the same native executable using its standard library; this example has no npm dependencies. Arguments remain separate, preserving paths with spaces. Source resources resolve relative to the .lay file.

1// Node uses the existing native CLI; there is no separate Node layout engine.2import {execFileSync} from 'node:child_process';3import {fileURLToPath} from 'node:url';4const binary=process.env.LAYMESH_CLI||fileURLToPath(new URL('../../target/release/laymesh',import.meta.url));5const source=process.argv[2]||fileURLToPath(new URL('../manual/line.lay',import.meta.url));6const output=process.argv[3]||'figure.svg';7execFileSync(binary,['validate',source],{stdio:'inherit'});8execFileSync(binary,['render',source,'-o',output],{stdio:'inherit'});

// Node uses the existing native CLI; there is no separate Node layout engine.
import {execFileSync} from 'node:child_process';
import {fileURLToPath} from 'node:url';
const binary=process.env.LAYMESH_CLI||fileURLToPath(new URL('../../target/release/laymesh',import.meta.url));
const source=process.argv[2]||fileURLToPath(new URL('../manual/line.lay',import.meta.url));
const output=process.argv[3]||'figure.svg';
execFileSync(binary,['validate',source],{stdio:'inherit'});
execFileSync(binary,['render',source,'-o',output],{stdio:'inherit'});

1node examples/integration/render.mjs examples/manual/line.lay /tmp/figure.svg

node examples/integration/render.mjs examples/manual/line.lay /tmp/figure.svg

Inspect nonzero process exit results in your application. LAYMESH_CLI selects another native binary. Browser code instead imports generated browser WASM bindings; a Node program cannot use browser-only font discovery.

Browser WASM lifecycle#

1import init, {render, language_query} from "./wasm/laymesh_wasm.js";2await init();3const source = 'page=canvas(size=(60mm,40mm))\npage.add(rect(size=(30mm,20mm),fill="#087f8c"))';4const filename = "/figure.lay";5const result = JSON.parse(render(source, filename, "{}"));6console.log(result.svg, result.inspection, result.warnings);7const help = JSON.parse(language_query(8    JSON.stringify({[filename]: source}), filename, "hover", 7, "en"9));10console.log(help);

import init, {render, language_query} from "./wasm/laymesh_wasm.js";
await init();
const source = 'page=canvas(size=(60mm,40mm))\npage.add(rect(size=(30mm,20mm),fill="#087f8c"))';
const filename = "/figure.lay";
const result = JSON.parse(render(source, filename, "{}"));
console.log(result.svg, result.inspection, result.warnings);
const help = JSON.parse(language_query(
    JSON.stringify({[filename]: source}), filename, "hover", 7, "en"
));
console.log(help);

render returns JSON, not a bare SVG string. Resources are a JSON name→text/byte-array map. Register actual font bytes before rendering text; prepare_render returns a job with svg()/inspection() when layout/render timing needs separation. language_query accepts UTF-16 offsets and analyzes source without evaluation. Error results throw JS exceptions containing diagnostics.

Native laymesh_render::render_export(&scene, extension, &ExportOptions) exposes the same options as the CLI; ExportOptions::validate supports preflight validation. This interface requires the native feature; browser WASM continues to provide SVG. Export formats and encoding options