#19619: Simplify words.py
-----------------------------+-----------------------------
Reporter: vdelecroix | Owner:
Type: defect | Status: new
Priority: major | Milestone: sage-6.10
Component: combinatorics | Keywords:
Merged in: | Authors:
Reviewers: | Report Upstream: N/A
Work issues: | Branch:
Commit: | Dependencies:
Stopgaps: |
-----------------------------+-----------------------------
Currently we have too many parent for words:
- for finite and infinite words (`Words_all`, `Words_over_alphabet`,
`Words_over_OrderedAlphabet`)
- finite words (`FiniteWords_over_OrderedAlphabet`)
- infinite words (`InfiniteWords_over_OrderedAlphabet`)
- words of fixed length (`FiniteWords_length_k_over_OrderedAlphabet` and
`Words_n`)
This lead to subtle bug like
{{{
sage: W = Words([0,1], finite=False, infinite=True)
sage: u = W.an_element()
sage: u[2:5].parent() # a finite word !!
Infinite Words over {0, 1}
}}}
The proposal of this ticket is to have only three classes:
- `FiniteWords`
- `Words_n`: words of length `n` (as a slice of the one before)
- `InfiniteWords` (or `FullShift`)
The parent `FiniteWords` should hence have a method `.shift()` that return
the associated shift (e.g `u ** Infinity` will belong there). Similarly,
the parent `InfiniteWords` should have a method `.factors()` that return
the set of factors (and finite slices will belong there).
--
Ticket URL: <http://trac.sagemath.org/ticket/19619>
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.
