[GiNaC-list] Two remarks.

[Chris Dams]

Dear Christian,

On Fri, 22 Apr 2005, Christian Bauer wrote:

> > Apparently somebody once upon a time had a reason not to consider index
> > dimension as operands.
>
> The dimension is an attribute of an index, but not a subexpression (it
> doesn't even show up in the default output of an index). It just happens to
> be of type 'ex'...

This is, besides defamation of index dimensions ("it doesn't even show
up!"), saying the same as I did in other words. What I am wondering about
is a real reason. Having index dimensions as an operand would be easier
sometimes (e.g., in matching and so on one has to know the index dimension
and it cannot be a wildcard, resulting in either seperately passing around
dimension parameters that are actually present in the expressions or calls
to functions with the sole purpose of finding out what the index
dimensions are) and I cannot really think of a reason why it would be bad
for index dimensions to be operands. Well, at the moment changing it would
probably be a bad idea because it would break existing code.

Best wishes,
Chris