How the Shim Works

The compile-then-eval pipeline, in the browser.

Step 1: Load the Shim

<script src="lykn-browser.js"></script>

lykn-browser.js bundles the JS reader, the JS surface compiler, the JS kernel compiler, and astring. It registers a handler that runs on DOMContentLoaded.

Step 2: Scan for Lykn Script Tags

The shim finds every <script type="text/lykn"> tag on the page:

document.querySelectorAll('script[type="text/lykn"]')
  .forEach(tag => {
    const source = tag.textContent;
    const js = lykn(source);    // compile
    new Function(js)();          // execute
  });

Step 3: Compile and Execute

Each tag’s textContent is compiled to JavaScript via the bundled compiler and executed. The compiled JS runs in the page’s scope — it can access the DOM, call fetch, use console:log.

External Files

<script type="text/lykn" src="app.lykn"></script>

The shim fetches the file, compiles it, and executes the result. This requires the page to be served (not opened as file://) because fetch doesn’t work on local files.

The shim doesn’t interpret Lykn. It compiles it to JavaScript and runs the JavaScript. The compiled output is identical to what lykn compile produces on the command line. The Lykn compiler is a compiler, even in the browser.

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