Some of the parsers are based on the wiki parser. They just add a little bit more functionality to this parser.
e.g. sstable can calculate formulars in a wiki table. It would be nice if such formulars could be added using the gui editor.
I don't speak currently about adding a whole spreadsheet calculation. It is more about to be able to add to a table cell =A0 + A5. The sstable parser then calculates it and shows rendered the result after saving.
sstable.py slightly modified for 1.7.1 can be further modified for using the argument parser