Re: [xsl] Get the duplicates in a list

["Michael Kay michaelkay90@xxxxxxxxx" <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>]

> 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