And now I've actually written the blog post :D
@martijnbraam Sounds like tagged templates in JS: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Template_literals#tagged_templates. You can prefix a template string with a function, and it will call the function with the strings and parameters as arguments.
@flyingpimonster oh that's interesting, I think this would be implementable in javascript then without any language changes.