[Email-SIG] Message threading

[Matthew Dixon Cowles]

[me]
> Jamie may not be Barry's favorite person

[Barry]
> Because he's got an out-of-date anti-Mailman rant on his site?

That was kind of what I was thinking. I agree with Jaimie a lot of
the time but I think that he can be a trifle, um, immoderate.

> I'll excuse both his anti-Mailman slant, and his becoming a bar
> owner (the dark side to us musicians :).

<grin> Becoming a bar owner is good. Without bar owners, I'd have to
do all my drinking at home.

> I'm +1 on adding support for threading to email 3.0.

Would you like me to extract my implementation of his algorithm and
clean it up so that you can look it over and decide whether or not
you want to use it as a basis for what goes into the module?

I imagine that we'd want a function that took a list of Message
objects and returned them after threading them. (It doesn't seem to
me that there's any value to merely munging the original list; it's
the Message objects that will be big here.)

I expect that we'd want a couple of arguments:

A function to sort siblings (default to soring by the date in the
date header).

An optional callback function to report progress since sorting a
large mailbox can take a while.

Perhaps an option to return either a flattened list or a
list-of-lists tree.

Regards,
Matt