til

in the browser you can compile modules and create instances from arrays of numbers/bytes, here's an obfuscated example: https://wasmgroundup.com/blog/wasm-compiler-in-a-tweet if the host provides the guest wasm module via imports a function to create and run from an array of bytes then it can be done today (if I understand you correctly). Here's some related content: https://github.com/pdubroy/til/blob/main/wasm/2024-02-22-Run...

Ah, I see! Yeah that's significantly trickier. re: "dynamically replace parts of the implementation as source code evolves" — there is a technique for this, I have a short write-up on it here: https://github.com/pdubroy/til/blob/main/wasm/2024-02-22-Run... About the debugging and inspecting — Inspecting Wasm memory is easy from JS, but to be able to do the debugging, you'd probably either need to rewrite the bytecode (e.g., inserting a call out to JS between every "real" instruction) or a self-hosted interpreter like wasm3 (https://github.com/wasm3/wasm3). (Or maybe there are better solutions that I'm not thinking of.)