You still need to go call into Javascript to do any kind of DOM manipulation. The solution I used for wasm-forth (a forth implementation targeting wasm), is to

You still need to go call into Javascript to do any kind of DOM manipulation. The solution I used for wasm-forth (a forth implementation targeting wasm), is to have a js "interpreter", implemented as a single function, that executes a sequence of DOM manipulation instructions, represented as an array of integers. On the forth side, the instructions are generated by a virtual DOM library: as the virtual DOMs are diffed, instead of manipulating the DOM directly it generates a sequence of opcodes to send in one go to the Javascript interpreter. The cost of the Javascript bridge is minimal: it's a single function call to render or update a whole page, and there is no serialization/deserialization involved since both languages can understand arrays of integers natively.