Running minimal code with changed inputs

[OmaymaS]

I am not sure if this topic was tackled from all sides but thought about sharing.

Problem When one runs a script, there could be a computationally heavy parts, but not all these parts require re-running. The inputs to these parts could be the same, the imported data might not have changed since the last time, etc.

In Rmarkdown, one can use caching in chunks to save some data importing. And in scripts one could write some conditions to control running some code.

It would be more efficient if there's a simple way to detect changes and decide which parts to be re-run automatically

So if there are available solutions for this, let me know. If not we might think about certain functions or settings to help with this.