++ A class of objects which can be 'stepped through'.
++ Repeated applications of \spadfun{nextItem} is guaranteed never to
++ return duplicate items and only return "failed" after exhausting
++ all elements of the domain.
++ This assumes that the sequence starts with \spad{init()}.
++ For infinite domains, repeated application
++ of \spadfun{nextItem} is not required to reach all possible domain
elements
++ starting from any initial element.
From the documentation of StepThrough, it is required that "init()"
stays the same.
Does your domain really need to implement StepThrough?
BTW, for those "Domain variables", there is no need to use Reference:
see commit 9dfdbc4cedc2d4a76230f707b238efe201d0a410 for example.
- Qian
On 1/22/24 23:15, Prof. Dr. Johannes Grabmeier wrote:
aha, this seems reasonable (but, who should know that?)
But, nevertheless problem is not solved: I now added a new exported
function
init : () -> %
BUT: same behaviour,
the code
init(): % ==
if mLP 0 then print hconcat [toOF "init() called using oneToN1 = ",
oneToN1 :: OF]
per oneToN (deref n1Ref)
still seems to refer to the one inherited from StepThrough, namely
init: constant -> %
Question: how can these 2 function be distinguished?
And even worse:
I cannot use the category StepThrough in my case, because the code in
the category uses the
init()-function with "contant". Obviously, implementing
init: constant -> %
there, one has not thought about the neccessity to switch that off in
cases where the
domain has feature to change internal variables.
That is not satisfactory, would need a possibility to force the system
at runtime to evaluate the function again, although it is defined with
"constant".
Am 22.01.24 um 16:00 schrieb oldk1331:
The "constant" can cause the compiler to cache the result and return
it directly next time, IIRC.
- Qian
On Mon, Jan 22, 2024, 10:39 PM Prof. Dr. Johannes Grabmeier
<[email protected]> wrote:
thanks, the rare instance of code for init() in the system, e.g. in
QuotienFieldCategory is as follows:
if S has StepThrough then
init() == init()$S / 1$S
my code says
init(): % ==
changes to
init: % ==
and
init: ==
both compile, but both do not change the wrong behaviour
Are there semantic differences between
f: constant -> %
versus
f: () -> %
Am 22.01.24 um 15:25 schrieb Ralf Hemmecke:
> I am not quite sure what the "constant" in this line actually means
> (Is that documented somewhere?), but intuitively it might be the
> sources of your "problem".
>
>
https://github.com/fricas/fricas/blob/master/src/algebra/catdef.spad#L1498
>
>
> Ralf
>
-- Mit freundlichen Grüßen
Johannes Grabmeier
Prof. Dr. Johannes Grabmeier,
Köckstraße 1, D-94469 Deggendorf
Tel. +49-(0)-991-2979584, Tel. +49-(0)-151-681-70756
Fax: +49-(0)-991-2979592
-- You received this message because you are subscribed to the
Google
Groups "FriCAS - computer algebra system" group.
To unsubscribe from this group and stop receiving emails from it,
send an email to [email protected]
<mailto:fricas-devel%[email protected]>.
To view this discussion on the web visit
https://groups.google.com/d/msgid/fricas-devel/3cb26dbf-3d60-47f4-9490-7b0a2b530e69%40grabmeier.net.
--
You received this message because you are subscribed to the Google
Groups "FriCAS - computer algebra system" group.
To unsubscribe from this group and stop receiving emails from it, send
an email to [email protected].
To view this discussion on the web visit
https://groups.google.com/d/msgid/fricas-devel/CAGBJN916frH6W2u1JoS%3DBep-rA0woUpLTw3GQsx7LR9eUYiYaA%40mail.gmail.com <https://groups.google.com/d/msgid/fricas-devel/CAGBJN916frH6W2u1JoS%3DBep-rA0woUpLTw3GQsx7LR9eUYiYaA%40mail.gmail.com?utm_medium=email&utm_source=footer>.
--
You received this message because you are subscribed to the Google Groups "FriCAS -
computer algebra system" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To view this discussion on the web visit
https://groups.google.com/d/msgid/fricas-devel/49e502c3-2ce1-4c93-aca0-0827ace81315%40gmail.com.
