We don't support that yet, but we are working on it. It's not that easy even if the theory is kind of simple to explain. The implementation in the different backends is mostly the challenge. The Python extension uses the Wasmer runtime (
https://github.com/wasmerio/wasmer) which supports 3 backends to generate executable code: Singlepass, Cranelift, and LLVM.
Cranelift is the easiest one to embed, and it brings a great balance between compilation time and execution time. That's the one used in the Python extension right now.
The “import functions” feature is also missing in the PHP extension (https://github.com/wasmerio/php-ext-wasm), but yeah, as I said, we are working on it. It's coming soon!