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CallOnGroebnerFanIdeals: better to use an iterator (or a "stream")

Added by John Abbott almost 8 years ago. Updated over 7 years ago.

Status:
New
Priority:
Normal
Assignee:
-
Category:
enhancing/improving
Target version:
CoCoA-5.?.?
Start date:
31 Aug 2016
Due date:
% Done:

0%

Estimated time:
Spent time:
0.45 h

Description

The fn CallOnGroebnerFanIdeals is not a good way of achieving its end.

Design and implement a better way.

Related issues

Related to CoCoA-5 - Feature #903: New function CallOnGroebnerFanIdeals: call function on GFan idealsClosed2016-07-04

History

#1 Updated by John Abbott almost 8 years ago

I have in mind a "stream", so the user could write CoCoA code like the following:

I := some_ideal;
foreach RGB in AllGFanIdealsSTREAM(I) do
  if not(has_nice_property(RGB)) then continue; endif;
  // store or process the interesting case
endforeach

I think such a notion of "streams" could be useful in many contexts (e.g. including cartesian products, integer ranges)

#2 Updated by Anna Maria Bigatti almost 8 years ago

but there is no such thing in CoCoA-5....

#3 Updated by Anna Maria Bigatti almost 8 years ago

John Abbott wrote:

I have in mind a "stream", so the user could write CoCoA code like the following:
[...]

Ok, that would be great indeed, but would require adding a type "STREAM" (and the semantic of foreach on it), correct?

#4 Updated by John Abbott almost 8 years ago

Yes, it would require some modification to the interpreter.

It would anyway be interesting to have such "stream" objects" also available in CoCoALib; perhaps they should not be called "stream" since that word is already used for I/O streams.

#5 Updated by Anna Maria Bigatti over 7 years ago

  • Related to Feature #903: New function CallOnGroebnerFanIdeals: call function on GFan ideals added

#6 Updated by John Abbott over 7 years ago

  • Subject changed from CallOnGroebnerFanIdeals: better to use an interator (or a "stream") to CallOnGroebnerFanIdeals: better to use an iterator (or a "stream")

After recently delving into the source code for the interpreter to handle interrupts as I'd originally intended, I am now more cautious about proposing changes to the interpreter... :-/

In any case, making it an iterator in C++ surely seems like a good idea; but the difference in behaviour would mean that translating "well" CoCoA-5 code to CoCoALib requires some effort if the code uses CallOnGroebnerFanIdeals. This is probably not so important unless we expect there to be a lot of such code...

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