Hot-code-reload: can we do it git driven?

[goodboy]

This has been on the idea backlog for a long while, obviously in pursuit
of something like what's in erlang's OTP and consequently elixer:

• https://blog.stenmans.org/theBeamBook/#CH-Calls
• https://blog.appsignal.com/2021/07/27/a-guide-to-hot-code-reloading-in-elixir.html

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Theoretical

• https://en.wikipedia.org/wiki/Dynamic_software_updating

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Ideas for a MVP:

Presuming we were to take the same protocol as erlang namely,
https://blog.stenmans.org/theBeamBook/#_hot_code_loading:

In Erlang there is a semantic difference between a local function call
and a remote function call. A remote call, that is a call to
a function in a named module, is guaranteed to go to the latest loaded
version of that module. A local call, an unqualified call to
a function within the same module, is guaranteed to go to the same
version of the code as the caller.

and we wanted reloads to be tracked and triggered by git history
updates, here are some thots on how to scratch at this:

• use watchfiles: https://watchfiles.helpmanual.io/ to auto-reload
  changed files

  • need to see if the anyio async support will work with trio:
    https://watchfiles.helpmanual.io/#how-watchfiles-works
  • consider other rust-python integrations for hot loading code
    maybe using something like
    rustpython or a wasm
    related exporter: https://github.com/RustPython/RustPython#wasi
  • check out what's possible in the tokio repl:
    https://tokio.rs/blog/2021-12-announcing-tokio-console

• figure out how to get full python code reload workin:

  • %autoreload support from ipython
  • rsyscall's wish API
  • it's worth reading a bit of theory on metaobjects
  • ptk has utils for not clobbering stdout which would be super handy for having multiple actors logging while your in the middle of debugging a crash.
  • search results for external libs in python:
    • https://github.com/hoh/reloadr
    • https://github.com/breuleux/jurigged
    • https://github.com/julvo/reloading

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Further related resources from #113:

• REPL driven dev from a lisp persepctive: https://mikelevins.github.io/posts/2020-12-18-repl-driven/

  • https://mikelevins.github.io/tags/programming/page/2/
  • https://www.youtube.com/watch?v=NqKyHEJe9_w

• more erlang/elixer links:

  • https://www.erlang.org/doc/reference_manual/code_loading.html#code-replacement
  • (same as above) https://blog.appsignal.com/2021/07/27/a-guide-to-hot-code-reloading-in-elixir.html
  • https://blog.appsignal.com/2018/10/16/elixir-alchemy-hot-code-reloading-in-elixir.html