Re: [xsl] XSLT 2.0 courses?

["Dimitre Novatchev dnovatchev@xxxxxxxxx" <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>]

> >   filter($sequence,$function) => head()
> >
> > This seems nice, however it will probably filter the whole sequence and
> > only then take the head() of the resulting sequence.
> >
> > Is there any guarantee that the evaluation of filter() will stop as
soon as
> > an initial item is produced?
>
> I wouldn't think there would be, given that filter() in general is
> specified to filter the whole sequence.

Maybe a smart optimizer can stop at the first filter result if the
expression is:

head( filter($sequence,$function))

Obviously we need a generators/co-routines mechanism... Would be ideal.


Dimitre

On Mon, Sep 21, 2020 at 12:17 PM Graydon graydon@xxxxxxxxx <
xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx> wrote:

> On Mon, Sep 21, 2020 at 07:06:21PM -0000, Dimitre Novatchev
> dnovatchev@xxxxxxxxx scripsit:
> > >   filter($sequence,$function) => head()
> >
> > This seems nice, however it will probably filter the whole sequence and
> > only then take the head() of the resulting sequence.
> >
> > Is there any guarantee that the evaluation of filter() will stop as soon
> as
> > an initial item is produced?
>
> I wouldn't think there would be, given that filter() in general is
> specified to filter the whole sequence.
>
> I would in no way _object_ to a first-available() that's guaranteed to
> stop as soon as it gets a true() result from $function.  And there's
> obviously a point past which one doesn't want to keep chaining
> "otherwise".  Frequency of the use-case might still be questionable.
>
> --
> Graydon Saunders  | graydonish@xxxxxxxxx
> CC&s oferC)ode, C0isses swC! mC&g.
> -- Deor  ("That passed, so may this.")
>
>


--
Cheers,
Dimitre Novatchev
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