Re: [Gestalt-users] New extension function

[Frans E. <fra...@te...>]

On Friday 14 July 2006 17:11, Colin Paul Adams wrote:
[...]
> =A0 =A0 Frans> Using letters is a step better, like flags for
> =A0 =A0 Frans> fn:tokenize() and so on.
>
> I don't think that's better at all.

Ok. Discussing it seems slightly redundant since I understand you're going =
for=20
the xs:anyURI approach instead, but I'm nevertheless curious of why you thi=
nk=20
so. I can think of many reasons why it's preferred:

* A lot less to type. (false(), false(), true()) more verbose than "abc".
* It gives at least a small hint what a flag does. "c" for "caching", for=20
example. With boolean one have only the order as key which is arbitrary.
* The user must think about the argument order. With letters that's=20
insignificant.

(Perhaps that's why the F&O functions are designed this way.)

I fail to see the advantages with booleans. Could you enlighten?

> However, I like the idea of supply a list of ws-separated xs:anyURIs.

It should also be specified what a flag can be expected to do. For example,=
 I=20
presume a flag can't alter the semantics of the function.

> =A0 =A0 Frans> However, I would prefer a whitespace separated list of
> =A0 =A0 Frans> xs:anyURIs where it is implementation defined which that
> =A0 =A0 Frans> are recognized(and where unrecognized are ignored). In this
> =A0 =A0 Frans> way any implementation can add performance settings in a
> =A0 =A0 Frans> portable way.
>
> But this is an implementation-specific extension function, so there IS
> only one implementation.

(Indeed, but it doesn't hurt designing things so others can adopt it, and=20
hence increase chances for portability. Also, perhaps this will move to=20
EXSL-T at somepoint, and then it can be done without changing your and othe=
rs=20
implementations.)


Cheers,

		Frans