#17979: Reimplementation of IntegerListsLex
-------------------------------------+-------------------------------------
Reporter: aschilling | Owner:
Type: defect | Status: needs_review
Priority: blocker | Milestone: sage-6.6
Component: combinatorics | Resolution:
Keywords: days64 | Merged in:
Authors: Bryan Gillespie, | Reviewers: Nathann Cohen, Jeroen
Anne Schilling, Nicolas M. Thiery | Demeyer, Travis Scrimshaw
Report Upstream: N/A | Work issues:
Branch: | Commit:
public/ticket/17979 | d976b2087e17107f748b1cbe05f3fab93ea81734
Dependencies: | Stopgaps:
-------------------------------------+-------------------------------------
Comment (by nthiery):
Replying to [comment:326 ncohen]:
> The function `_possible_m(self, m, j, min_sum, max_sum)` takes four
parameters, all of which are attributes of `self`.
>
> {{{
> if self._next_state == LOOKAHEAD:
> m = self._current_list[-1]
> if self._possible_m(m, self._j,
> min_sum - (self._current_sum-m),
> max_sum - (self._current_sum-m)):
> }}}
>
> It would make more sense to me if this function had no arguments at all.
I agree that this should eventually become an argument-less
`look_ahead` method that tests if the current list could possibly be a
prefix of some valid list.
I would like to postpone this change to #18055 however: anyway this
method will need to be rewritten there (in particular to handle an
empty `current_list`), and changing the interface now would require
rewriting most of the current tests of `_possible_m` to construct a
bunch of different IntegerListsLex objects instead of just passing
various arguments. Note also that, as specified in the doc, `min_sum`
and `max_sum` do not exactly match the corresponding attributes: they
are bounds on the tail of the list only (agreed, the difference above
could be done in _possible_m).
Cheers,
Nicolas
--
Ticket URL: <http://trac.sagemath.org/ticket/17979#comment:349>
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 unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
Visit this group at http://groups.google.com/group/sage-trac.
For more options, visit https://groups.google.com/d/optout.
