heavy Processor called multiple times

[planetis-m]

Hi,

I've developed a prompt that performs spellchecking by integrating the pyspellcheck library. However, I've noticed that underlining misspelled words causes a significant lag. I've optimized the spell-checking process by using caches, but the lag persists.

Upon further investigation, I added a print statement to the apply_transformation function and found that it is being called four times per keystroke. I attempted to create a ConditionalProcessor to address this, but there is no key_inserted event. Instead, I implemented hashing the buffer's text, but this approach breaks the underlining functionality entirely.

Any advice on how to resolve this issue would be greatly appreciated.

Thank you!

Sample: https://gist.github.com/planetis-m/ad078e0e184439e2712f3b853c192d01

[planetis-m]

I tried creating an async Filter, this didn't work:

venv/lib/python3.12/site-packages/prompt_toolkit/completion/base.py:346: RuntimeWarning: coroutine 'AsyncSleepFilter.__call__' was never awaited
  if self.filter():
RuntimeWarning: Enable tracemalloc to get the object allocation traceback

[nitanmarcel]

I hit the missing async pre-processor thing too when wanting to implement a hover for a language server integration in my code. @jonathanslenders An async Processor would be handy. Until then, running the spell checker asynchronous and calling in from a non async code is a viable solution. asyncer can handle this easily by automatically running the async code on another thread.

https://asyncer.tiangolo.com/tutorial/asyncify/
https://asyncer.tiangolo.com/tutorial/syncify/#run-async-code-from-blocking-code