Subject: About Bug 1742275: featurep(false, 'complex)
From: Harald Geyer
Date: Sun, 15 Jul 2007 15:19:22 +0200
> > Ideally I'd also like to see some possibility to specify the defaults
> > for undeclared symbols and some uniform way to query this information.
> > Right now we have the variable "domain", but it isn't used enough.
>
> Agreed about "domain", but probably a big job to fix that.
> solve(x^2+1,x) would have 0 solutions, not 2, asin(2.0) would give an
> error (or return itself), etc. etc.
That's not really what I have in mind: solve() doesn't care about
declarations at all - whether this is ok is a different issue.
Restricting the result of a function, is not a matter of declarations
either. If you think that the above should be governed by "domain" then I'll
have to think about a new variable ...
What I want is a way to specify how undeclared symbols will be interpreted.
> A lot of work.
It wont be too much work to review the calls of "decl-complexp",
"kindp" et al and substitute them with a new clever function where
appropriate. That's why I raised the question, how such a function
should look like, in my last mail. Still not sure.
An other, even more important question: Which features can be global
defaults? Anything else besides complex/real?
integer comes to my mind, but even if this would be useful to some
users, maxima probably doesn't have the capabilities to cater for
their needs anyway.
scalar/nonscalar looks like good candidates to me.
How should this work? Multiple separate variables? One list of
enabled default features?
I think these are the most important questions to answer, before making
a concrete proposal. In case anybody has an opinion, input is much
appreciated.
Harald