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Re: RE: logical operators in *test*

2003-10-29 09:48:46
I think you are missing Mike's point. It doesn't make any difference at all 
what development background you 
come from - you don't learn any new programming language by guessing at syntax. 
Many C programmers learn C by 
reading K&R's book (or one of thousands of others). They may have earlier used 
languages that used AND or OR, 
but clearly that syntax is not going to get through any C  compiler I've ever 
used.

---LwM---


Michael Kay said:

Why do people have such difficulty discovering this basic information?
(I am seriously interested to know, because it's such a frequent
problem).


I can offer a theory, but is it accurate I can't say because I didn't have
the problem myself.

My main assumption is that most XSLT developers come from developer
backgrounds.

In programming, nearly every language has two AND/OR concepts: bit wise and
logical.  Some clearly differentiate the two, like C with the && and &
operators, and some don't.  That means depending on from which path a
developer comes to XSLT, they may never have seen the "words" AND or OR in a
program in their lives.  (This is similar to the procedural vs. functional
confusion in XSLT.)

The other side, which isn't always thought of, is that English, as it is
used by a lot of people, doesn't use AND and OR in a strictly logical sense.
You'd ask: "How many people live in London and New York?"  We know what is
meant: in a logical sense the query most likely means "How many people live
in London or New York?"  And just typing that feel awkward.  Of course,
there are times when we mean AND in the logical sense: "How many people live
in the UK and earn more the 500,000 Pounds a year?"  This may drive some
people to specifically look for unambiguous language operators for AND and
OR rather than using the "words."

Is any of this right?  Well, probably not, although I'm sure if you were
developing in C prior to moving to XSLT, you'd start by using && and ||
rather than AND and OR.

      Steve

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Systems and Electronic Resources Service
Logic School
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