#13687: Parents for groups
--------------------------------+-------------------------------------------
       Reporter:  vbraun        |         Owner:  joyner  
           Type:  enhancement   |        Status:  new     
       Priority:  major         |     Milestone:  sage-5.5
      Component:  group theory  |    Resolution:          
       Keywords:                |   Work issues:          
Report Upstream:  N/A           |     Reviewers:          
        Authors:                |     Merged in:          
   Dependencies:                |      Stopgaps:          
--------------------------------+-------------------------------------------
Description changed by vbraun:

Old description:

> Groups are based on the deprecated `ParentWithGens`. This ticket is about
> forward-porting them to the new coercion framework.
>
> To limit the size of the patchbomb I'm only porting the Abelian groups.
> The rest depends on `old.Group`
>
> Various oddities needed to be cleaned up in the process:
> * make parents unique and elements immutable (often requires tuples
> instead of lists)
> * rename `AbelianGroup_class.invariants()` ->
> `AbelianGroup_class.gens_orders()` since they are not necessarily the
> abelian invariants (=elementary divisors).
> * rename `element.list()` -> `element.exponents()` for the exponent
> vector.
> * implement a `AbelianGroupWithValues` where you attach values to the
> (abstract) generators. Used in the unit group of a number field, for
> example.

New description:

 Groups are based on the deprecated `ParentWithGens`. This ticket is about
 forward-porting them to the new coercion framework.

 To limit the size of the patchbomb I'm only porting the Abelian groups.
 The rest depends on `old.Group`

 Various oddities needed to be cleaned up in the process:
 * make parents unique and elements immutable (often requires tuples
 instead of lists)
 * rename `AbelianGroup_class.invariants()` ->
 `AbelianGroup_class.gens_orders()` since they are not necessarily the
 abelian invariants (=elementary divisors).
 * rename `element.list()` -> `element.exponents()` for the exponent
 vector.
 * implement a `AbelianGroupWithValues` where you attach values to the
 (abstract) generators. Used in the unit group of a number field, for
 example.
 * lots of places return lists when they should return tuples

--

-- 
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/13687#comment:1>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica, 
and MATLAB

-- 
You received this message because you are subscribed to the Google Groups 
"sage-trac" group.
To post to this group, send email to [email protected].
To unsubscribe from this group, send email to 
[email protected].
For more options, visit this group at 
http://groups.google.com/group/sage-trac?hl=en.

Reply via email to