Design #1407: Tagged values (Hilbert Series) - CoCoA-5 - CoCoA Project

Design #1407

Tagged values (Hilbert Series)

Added by John Abbott about 4 years ago. Updated about 2 years ago.

Status:

Closed

Priority:

Normal

Assignee:

Anna Maria Bigatti

Category:

bug

Target version:

CoCoA-5.4.0

Start date:

30 Jan 2020

Due date:

% Done:

100%

Estimated time:

1.51 h

Spent time:

1.20 h

Description

Bernhard Andraschko has a new program which calculates Hilbert series.
He would like to make it produce a result compatible with the result produced by the fns in hp.cpkg5.
The problem is that tagging takes into account the "active" package at the time that the tag was applied.
So he gets an object of "type" TopLevel.HPSeries instead of hp.HPSeries; and the fns in hp.cpkg5 refuse to handle his Hilbert series (e.g for printing).

How to resolve this? Neatly!

hp.cpkg5 (16.1 KB) hp.cpkg5

Anna Maria Bigatti, 31 Jan 2020 14:00

History

#1 Updated by Anna Maria Bigatti about 4 years ago

Assignee set to Anna Maria Bigatti
% Done changed from 0 to 20

Fate wants that I'm facing exactly the same problem!!

And I have a neat idea in mind!
Bernhard: which tags do you need? just HPSeries?

#2 Updated by Bernhard Andraschko about 4 years ago

Yes, i just want to create a "new" Hilbert series without knowing a generating system of the ring corresponding to it.
For getting the values of the Hilbert function I have to do EvalHilbertFn(HS,d) which involves a type check.

#3 Updated by Anna Maria Bigatti about 4 years ago

Done.
The solution I implemented is this. (a bit like public/private functions in C++)
The package $hp, responsible of the tags, exports the functions

TaggedHilbertFn(X);
TaggedHilbertSeries(X);

which return X with the desired tag.
I modify hp.cpkg5 so that it uses these functions internally as well.

From other packages this is the only way to assign the tags (Giovanni Lagorio actually made a good design, preventing tags outside the defining package!!).
When I have time, I'll also add some sanity check on X, for example that it must be a record with suitable fields. This way the "tag" will also be a certification of well formed object.

I think this is neat!