Re: [xsl] Reference to variable cannot be resolved.

[David Carlisle <davidc@xxxxxxxxx>]

> You can do the same thing in other languages:
yes, of course.

> The main diference is that in xsl you can't change it's value,
 
which isn't peculiar to XSL it is common to all other declarative
languages and is the common understanding of the term "variable"
in mathematics where this use of "variable" for an identifier
originated. 

Am I just getting old?

when I was first taught programming (Fortran at school, mid 70's)
the number one "big issue" that the novice programmer had to get past
was that programming languages had a strange warped notion of
variables and variable assignment in which
i=1
i=2
wasn't a contradiction, it was a sequence of instructions and similarly
i=i+1
didn't imply 0=1.

It was explained that computers were not up to the kind of reasoning
commonly used by people and so these strange computing languages had to
break everything down into procedural instructions that could be
executed.

But now (actually, earlier if you were in the right place) there are
languages that are capable of handling far more natural modes of
expression, but it seems that a generation of using procedural languages
has made people think that there is something natural about that way of
thinking and that "natural" "declarative" programming languages are
somehow weird in not allowing side effects and variable redefinitions.

David

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