Stef, Alexandre,
I will grant you a head start: if you have to copy code, it's not
the
same thing. My next question would be whether a competitive "say it
once" design could be realized with composition and single
inheritance.
Alexandre refers to use cases the show an advantage, and I do not
dispute that. I am mostly just curious at this point. Is there
more or
less overhead specifying the traits vs. arranging for good
composition?
My guess would be that the traits win, but I have no data to support
that. Is there a performance advantage either way?
Unless traits are (whether used or not) very expensive at runtime, I
would argue that anything that gets us better test coverage is a
good
thing.
Bill
Wilhelm K. Schwab, Ph.D.
University of Florida
Department of Anesthesiology
PO Box 100254
Gainesville, FL 32610-0254
Email: [EMAIL PROTECTED]
Tel: (352) 273-6785
FAX: (352) 392-7029
[EMAIL PROTECTED] 10/06/08 2:32 AM >>>
you can achieve the same with copy and paste or code generation.
What
is nice with traits is that they
represent a bloc of coherent behavior that can be parametrized. Load
the latest Collection-Tests from the
pharo source. This is just the start but this is quite cool. Check
TEmptyTest. It is applied to
OrderedCollection, Basg, Set, Array, Interval (and could be to
others
too).
Yesterday I got a really nice presentation of Miro by alain plantec
and he is also using traits.
Stef
On Oct 6, 2008, at 3:35 AM, Bill Schwab wrote:
Stef,
Dumb question: are traits essential to it, or simply a way of
achieving
it? Just curious, as I am still trying to put traits in
perspective.
They strike me (so far, right or wrong) as a form of multiple
inheritance, which I have assumed (right or wrong) is often not
needed
with clever aggregation/composition of single-inheritance objects.
One
very slick use of multiple inheritance in C++ provides an easy
way to
implement COM objects with multiple interfaces - not that I have
any
desire to do that, but it is slick for C++. Whether that says
something
about multiple inheritance's strengths or about C++'s weaknesses,
I'm
not sure :)
Pearls of wisdom will be eagerly assimilated.
Bill
Wilhelm K. Schwab, Ph.D.
University of Florida
Department of Anesthesiology
PO Box 100254
Gainesville, FL 32610-0254
Email: [EMAIL PROTECTED]
Tel: (352) 273-6785
FAX: (352) 392-7029
[EMAIL PROTECTED] 10/05/08 5:37 PM >>>
Hi guys
I did a fun coding session in the train to brest. I started to code
collection tests
as traits (as damien did for stream) and this is reallllly cool.
I could write some tests and apply them to
OrderedCollection, Set, Bag, Interval.....
I will publish that and continue. I imagine that the coverage for
Collection is
increase a lot.
Stef
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