Re: [xsl] except (was: Keys with duplicates should be simple)

[Ihe Onwuka <ihe.onwuka@xxxxxxxxx>]

On Mon, Feb 3, 2014 at 8:16 AM, Michael Kay <mike@xxxxxxxxxxxx> wrote:
>
> On 3 Feb 2014, at 07:18, Ihe Onwuka <ihe.onwuka@xxxxxxxxx> wrote:
>
>> If indeed except is equivalent to the set-theoretic difference
>> operator would it be beyond the pale to admit difference into the
>> syntax as a synonym for except.
>>
>
> You haven't answered my post in which I attempted to show that the XPath usage of "except" was consistent with the natural language use of the term.
>

To me the natural language interpretation of except has the RHS of the
except interpreted within the context of the LHS. If you are talking
natural language - natural language interpretations don't allow for
XPath abbreviations and if I read you rightly you are saying this
would be natural if you allow for the effect of XPath abbreviations.

> I think that using "difference" would confuse an awful lot of people who would assume, without reading the spec, that it meant magnitude difference (e.g. subtract, or date difference).
>

Well thats a problem of applying a mathematical construct outside of a
mathematical domain, hence why I suggested the difference as
alternative syntax  to keep both sides happy (if indeed they are the
same thing).

I worked at an investment bank before going to university and never
did A levels  so I walked into my first Calculus class thinking that a
derivative was a financial instrument and a slope was something you
skied on. It is not feasible or desirable to go through life clinging
on to
these non-mathematical interpretations.