Questions or comments
Tue Mar 27 13:22:02 2001
>You asked for it, so I have some comments from quickly browsing through
>your sources. I have also taken a quick look at Armin Rigo's Bazar code
>in Python. I have been discussing some stuff with a friend and I am
>thinking if I should also post something to the Tunes list.
>While using '->' as a selector might be a problem, you could have '=>'
>(though I see you used '>=' and '<=' and that might cause some
My current working set now uses '->' and I think that I can live with
that. Other external sugarings like @ and => I have kept for the use
of the programmer. This release will make it out in another week or
> Notice that ArrowGraph extends Arrow, so it has a head and tail.
>But the code says it is a subclass of ArrowStub. Later you talk about
>the apexArrow in a way that made me think this comment was about some
Indeed it does. I changed inheritance from Arrow (which made identity
problems difficult by making the relationship between Arrows and
ArrowGraphs less flexible) to delegation to apexArrow. FrameGraph is
going to handle the relation between the two. I will fix this
>In Arrow>>head:tail: is didn't get this
> self become: newArrow.
> head _ Reference to: headArrow.
> tail _ Reference to: tailArrow.
> self become: newArrow.
>Given that newArrow has nil in its instance variables, wouldn't this
> newArrow head: headArrow tail: tailArrow
>The "recursive" call to head:tail: would take care of the "Reference
>to:" stuff, right?
I was having a lot of problems with initialization of Arrows, and
this snapshot shows some of the conceptual confusion that resulted.
The next release should be less confusing. I already have a different
set-up for initialization which is nicely robust and a little clearer.
But now that you mention it, I really should put a better comment in
there to explain what's going on and why.
>Comments like in here
>!Arrow methodsFor: 'testing' stamp: 'btr 3/18/2001 01:42'!
>isCompositionOf: anArrow1 with: anArrow2
> "Answers whether the receiver is a valid composition result of
> arguments in either order."
> "^ anArrow1 coincidesWith: anArrow2 coords: 1@2"
> ^ self == (anArrow1 ++ anArrow2) | self == (anArrow2 ++
>don't seem to agree with the definition of Arrow>>at: (since it seems
>to imply a 1 based indexing scheme while at: implements a 0 based one),
>but it is likely that I misunderstood something.
Nope, you found a mistake of mine. #coincidesWith:At: was added after
much of everything else, and I was using the arrow logic texts as a
guide, without checking for consistency. I fixed this just now.
>There is a SmartRefStream method (around line 1940) that probably
>shouldn't be there.
That's a changeset problem (I think). I'll make sure to condense my
changes for the next posts.
>Sorry that I am unable to make higher level comments than these...
That's fine, most of the methods right now are basic utilities. I am
cooking up some factories with lots of large-scale patterns right
now, and they should indicate the desired characteristics of the
system at large. Also the more useful routines will make it explicit
when we are using a categorial nature or a strictly informatic
nature. Also the SmalltalkMOP routines are unusable as is.