[tmql-wg] TMQL, next round

Lars Marius Garshol larsga at garshol.priv.no
Sat Mar 10 09:24:19 EST 2007


* Lars Marius Garshol
>
> There is no "the set of functions" associated with any particular
> datatype, which I think is what's underlying the other Lars's point.

* Robert Barta
>
> Hrm, well people with category theory background would probably
> strongly disagree with you. They would argue that a type _IS_ actually
> a product of all the functions available for a data structure.  
> Keywords
> "abstract data types", "encapsulation", "OO programming" (the real
> one, not Java).

Yes, they would, and I don't disagree. However, that only applies  
after you have defined the types and finished the language. At that  
point, you can consider the set of values + all the functions to *be*  
the type. Fine. However, I would be very surprised if you could find  
a single person who believes that for the "datetime" datatype there  
is only one possible set of functions that might be included in the  
language. In other words: the committee can freely choose what  
functions it wants to include in the language for any particular  
type, and there is no obligation to make it exactly the set of  
functions provided by XPath 2.0 for that datatype.

> True, I would not underestimate the costs to implement a larger body
> of functions even if you can rely on existing libraries. And it is
> unbelievably boring, too :-))

Yes. So I think we agree we need to be conservative in including  
functions.

--Lars M.



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