Option to configure persistent caching for all cells within app or directory

[leventov]

Description

When the notebook is used locally always saving all results to disk is cheap. Therefore it makes sense to alleviate the cognitive burden for developers (assessing whether the cell is "expensive" or not) and source code clutter (that is, extra @persistent_cache decorators) by providing an option configurable per-app or per-directory (such as in a .marimo/config yaml/config file) to automatically save and invalidate the results of all cells whenever they are changed.

Suggested solution

As described above.

Alternative

An App subclass, such as PersistedApp? But the problem with this is that it still has decision burden (per app rather than per cell, but still), and it cannot be dropped transparently when the app is deployed on the web.

Additional context

No response

[dmadisetti]

Yes! I have a working branch that does this. There are a few bugs, and will probably go into experimental .toml setting for now.

Can you expound more on what you mean by having persistent cache for a directory?

[leventov]

Can you expound more on what you mean by having persistent cache for a directory?

I meant that this configuration (persist all cells by default, opt out is possiblle) applies directory-wide to all marimo notebooks stored within a directory, unless specifically overriden on the app level, a la App(default_cell_persist_results=true|false).

[gabrielgrant]

This would be great, so long as it is paired with:

1. Some indication of whether results are being computed or coming from cache
2. An easy way to clear/ignore the cache and recompute