[cwyers]

Yeah, the thing is, you can't do this in a file-format-agnostic way (you need to know what a Word doc or an Excel sheet is), which makes the file system layer the wrong level of abstraction to consider.

[enriquto]

You can, as long as your files have a meaningful representation as a text file. This is a good idea anyways.

[eru]

That representation is one way to encode the file-format knowledge you need.

Any other way to implement would probably also involve one common format (or a small few) behind the scenes.

[cowsandmilk]

The diff when database-backed is still going to be file-format specific because a text-based document will not be stored in a DB identically to a spreadsheet.