Re: Unit validation in spreadsheets

[Uri David Akavia <uridavid netvision net il>]

> > Right -- our design addresses exactly that issue.  For each 
> > function F, such as SUM, we generate a "unit transformer" F^ 
> > that does the right thing.  When there's circularity, this 
> > setup breaks down because the recursion doesn't terminate.
> > For that case, we use constraints that can be solved 
> > straightforwardly.  
>
> That is going to be a huge amount of work in some cases.  There are
> on the order of FIVE HUNDRED functions.

Does this transformer/validator have to be created per function (for all
functions?). Isn't there a more minimalist approach available - for
example, adding and subtracting need to take the same units, whatever
they are. Multiplication and division can take any unit. Other functions
might not care about units.
So divide the functions into functions that care, and functions that
don't. My guess is that financial functions just won't accept any units
(for the initial step), and so might a lot of other functions.
My guess is that if you limit units to functions who can actually care
about them, there will be far less than 500.

Yours,

Uri David Akavia