Hi Hugh,

Eric Webster and I want to make some changes to
SemistandardTableaux(p,mu).  This is the first change I've tried to
make to Sage, so I'm not totally sure of the protocol, but it was
suggested to me that I should describe here what we plan to do (as
well as opening a trac ticket, which I will do shortly).

Great! Yes, discussing proposed changes is probably a good idea.
You can either first put your changes on the sage-combinat server,
so that people can use and view your code, or as you wrote, you
can open a trac ticket and post your changes there.

Mostly, we want to make a change to add a feature, so that one can
specify an additional keyword argument max_entry=k so as to get the
Semistandard Tableaux(p,mu) with entries in 1..k, or max_entry=-1 so
there is no maximum.  (Currently, the entries are in 1..|p| unless mu
is specified, and I would keep that as the default.)  So our proposed
change is just an enhancement and presumably won't screw anything up
if done right.  I do also want to change __repr__ so it always
explicitly says what the maximum entry is.

I agree that being able to specify the maximum entry is a natural
thing to do (and is not always |p| in many applications).

While looking at the code, though, I noticed something a bit wierd
about the way SemistandardTableaux(p,mu) operates.  As it stands, p
can be an integer, a partition, or None, and mu is an integer vector
describing content.  If p is an integer, it returns all tableaux of
size p (and with content mu if mu is specified).  If p is a partition,
it returns all tableaux of shape p (and with content mu if mu is
specified).  If p is None, it ignores mu.  This seems wrong: surely it
ought to give you all tableaux of content mu and size |mu|.  So I
wanted to change that.  But it's not because I really need it, it's
just tidy-mindedness.  If anyone suggests it's a bad idea to do this
part, I won't.

I am not sure why this was done. I assume you want to edit the lines
around  2264 in tableau.py.

Cheers,

Anne

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