Spreadsheet display mode

[Richard Stallman]

Someone suggested that Emacs should have a spreadsheet display mode.
I did some thinking about the idea.  A list of cell definitions could
control how to display each line, and they could go in a `display'
property that might be on an overlay or text property (so that you
could display just a part of the buffer as a spreadsheet).

The actual text would use delimiters to separate cell contents.
The cell definitions could specify what delimiters to use.

What do you think?