Re: Unifying Iteration and Viewports

On Wed, Mar 16, 2016 at 2:22 PM, Norman Walsh <ndw@nwalsh.com> wrote:
> James Fuller <jim@webcomposite.com> writes:
>> (B) An iteration of the sections that produces an empty sequence:
>>
>> why not empty parens to represent sink()
>>
>>    $doc//section ! ()
>
> When does this have value?

The sink was a simple example.  Iterating a value and running a flow
for each value is very useful.  Much of my use of viewports is
actually a form of such iteration because the output has no value
except for logging purposes.  That logging can be done other ways.

So, more like:

   $doc//section ! { ... complex flow with no output ... }

results in an empty sequence.


The bang (!) operator is from XQuery ...

>
>> we probably need to come up with a more realistic example.
>>
>> (C) 'replacement of sections'
>>
>>   $doc ~ //section ! filter() ~
>>
>> Personally would like to avoid spending weeks/months/years discussing
>> C) ... I observe that viewports has taken up a huge amount of mental
>> capital for the WG over the years and while it is very useful I think
>> trying to solve it to achieve parity in the language is a rathole best
>> avoided.
>
> My knee-jerk reaction is that XProc isn’t useful without
> viewport/replace.

Hmmm... if we make iteration easy it will be very useful without it..


-- 
--Alex Miłowski
"The excellence of grammar as a guide is proportional to the paucity of the
inflexions, i.e. to the degree of analysis effected by the language
considered."

Bertrand Russell in a footnote of Principles of Mathematics

Received on Wednesday, 16 March 2016 22:14:39 UTC