Project Plan

Get WebAssembly Host Functions working

Use an existing Rust example to read stdin/stdout using wasmtime on both sides.
Then try putting a host function call and use dependent data so we know that it worked on both sides (just ints for simplicity)
Then get it working with strings as a different method
Then get wasmtime.net project set up with the first Rust example (just stdin/stdout)
Then test the host function with just the ints
Then the host function with strings
Once that's working, make an example tinygo and javy version that calls the same string host function
Then wrap these into single command compilers that are cross-platform.
Figure out how to get async/await working in javy
Fork javy and make a version that uses the module system and the patched host function, so you just pass in the js code
investigate the possibility of doing the same shared runtime with tinygo like javy does

Host is Go, Rust is the plugin language
Example .wasm file already precompiled
Passes string from plugin to host via pointer and length
To get string return value from function, the following process happens:
- Host function returns just a response length in bytes
- Plugin allocates length bytes
- Plugin calls ANOTHER host function, write_mem, passing a pointer to the memory location that was allocated
This is complicated, and would be a lot simpler if the host function could allocate memory in the address space, put the response in that memory space, and then return a pointer to that memory space instead.
- Is this not possible? does the host not have access to allocate memory in the plugin?