Re: [xsl] Get the duplicates in a list

["David Birnbaum djbpitt@xxxxxxxxx" <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>]

"Partly because it's an expression, not an instruction"

Thanks, Michael. Understood.

On Fri, Jan 3, 2025 at 10:30b/AM Michael Kay michaelkay90@xxxxxxxxx <
xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx> wrote:

> >
> > Off topic, but following a train of thought: Was there a particular
> reason behind the design decision that XPath *if* expressions would require
> an *else* clause?
> >
>
> Partly because it's an expression, not an instruction: if you look at
> conditional expressions (like the dreadful ternary operator in C-based
> languages) it's normal to require an explicit result from both branches.
>
> Partly to avoid the "dangling else" ambiguity.
>
> Basically, a desire to avoid repeating the mistakes of the past.
>
> There was a lot of discussion of syntax for conditional expressions in XP2
> timescales, and an awful lot of arguments were raised for different
> positions, but even if you have access to the full discussion, it's not
> easy to work out why the committee adopted one particular position. Very
> often Don Chamberlin or Mary Fernandez would do a good job of collating all
> the proposals and the arguments for and against each one and present the WG
> with a clear summary of the argument. It does tend to come down to
> individuals being persuasive (or not).
>
> XP4 does have an else-less if. Again, there was a lot of discussion.
>
> Michael Kay
> Saxonica