Karim BELABAS on Sun, 4 Nov 2001 14:39:00 +0100 (MET)


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Re: pari-2.2.1.alpha released


On Thu, 1 Nov 2001, Ilya Zakharevich wrote:
> Then there is another feature which is badly missed: subst(a, [x,y], [z,t]).
>
> BTW, is there a "better" semantic than doing substitutions
> left-to-right?  Here "better" meaning one or more of "more
> convenient", "more functionality", "less surprising".

There should be a way to choose between 'left-to-right' (sequential) and
'parallel' (simultaneous) substitution. Both are relatively easy to
implement.

I'm not sure about which of the two modes should be made the default (which
would be the least surprising). I would vote for 'parallel', with a flag to
insist on sequential substitution.

> P.S.  Unrelated: is there a way to catch err()/error() from GP?
>       Simple API to catch from PARI?

trap() is a start (I'm not too happy about the API...)

    Karim.
-- 
Karim Belabas                    email: Karim.Belabas@math.u-psud.fr
Dep. de Mathematiques, Bat. 425
Universite Paris-Sud             Tel: (00 33) 1 69 15 57 48
F-91405 Orsay (France)           Fax: (00 33) 1 69 15 60 19
--
PARI/GP Home Page: http://www.parigp-home.de/