LyndonWords from composition beginning by 0's

[Adrien]

LyndonWords, when applied to a composition starting with 0's, gives a wrong result, e.g.:

for w in LyndonWords(list([0,1])):
    print w

return 1 instead of 2, and in a similar vein

for w in LyndonWords(list([0,2])):
    print w

return '12'

The problem is also described here :  http://groups.google.com/group/sage-combinat-devel/browse_thread/thread/5c4b691a692b56b0#

The problem is that necklace._sfc() ignores 0's at the begining of a list.

A modified lyndon_word.py file which fix the problem is attached.

Apply:

• trac_12997-LyndonWords-compositions.patch
• trac_12997-LyndonWords-review-ts.patch
• trac_12997-Lyndon-review-fc.patch

[Adrien]

Modified lyndon_word.py

[Adrien]

diff

[saliola]

Hello Adrien, can you post a patch with your changes instead of the .py file?

You can follow Sébastien's guide on  http://thales.math.uqam.ca/~labbes/Sage/how-to-contribute/ How to contribute to Sage (especially steps 15 to 17).

[Adrien]

patch

[jdemeyer]

Please fill in your real name as Author.

[tscrim]

Please add some tests to the __iter__ method showing the ticket has been fixed such as:

TESTS:

Showing :trac:`12997` is fixed::

    sage: LyndonWords([0,1]).list()
    [word: 2]
    sage: LyndonWords([0,2]).list()
    []
    sage: LyndonWords([0,0,1,0,1]).list()
    [word: 35]

Thanks,
Travis

[tscrim]

I've attached the review patch which adds the doctests and tweaks the code format. Could someone give this a quick second review please?

Thanks,
Travis

[chapoton]

Ok, this looks good to me.

I have added a patch to change the "raise" to python3 syntax

positive review

[tscrim]

Thanks Frederic!