[e-lang] Two-vat figure
markm at cs.jhu.edu
Tue Jun 21 11:19:49 EDT 2005
Ka-Ping Yee wrote:
> I've posted a new design for the two-vat figure at
Ping, this is good. I very much like the direction this is going.
The current draft of the paper will now be at
<http://www.erights.org/talks/promises/paper/>. I put your draft 2vat diagram
in as best I could, starting from the .png bitmap. Could you post the .svg
> 1. The diagram is rearranged to read mostly left to right, instead
> of bottom-right to bottom-left to top-right. Reasoning:
> left-to-right reading order is more natural.
Definitely a good move.
> 2. The stack and queue are integrated into the structure of the vat.
> Reasoning: they are a part of the way the vat works, so they
> shouldn't look like other objects just floating around in the vat.
> 3. The vats and objects are given non-cryptic names. Reasoning:
> words are easier to understand than abbreviations like XL.
> (Mark, i know you said you preferred not to do this. We can
> change it back if you want, but i wanted to at least show what
> i originally had in mind.)
Let's wait on the renaming issue - leave it this way for now. (In any case,
even if we do keep readable names, these are the wrong names.)
There should be spaces around the "<-".
> 4. The sequence of steps is labelled in a distinct style (white
> on black filled circles). Reasoning: the sequence of steps
> should draw the eye.
> 5. Descriptions are added to steps 2, 4, and 5. Reasoning: an
> explanation helps show what is going on here; the message
> names in the original figure aren't enough.
> 6. Dotted arrows are added to show the eventual message being
> placed on the queue and removed from the queue for processing.
> Reasoning: without these arrows, it looks like the message is
> being delivered immediately. The arrows also make it clear
> that the message arriving, the message on the queue, and the
> message being delivered are one and the same message. (In
> the original there is no clear cue that the message on the
> queue is the message on the incoming pointer.)
> 7. The number 33 is moved inside the message arrow. Reasoning:
> too many arrows produce visual clutter. The 33 is a selfless
> value, so the semantics are unchanged, the diagram is clearer,
> and the messages containing 33 also appear more distinct.
I think that's good.
> 8. The message arrows now point right instead of left. Reasoning:
> this makes more sense with the left-to-right reading order
> since the messages travel from left to right.
Definitely the right thing.
> 9. The shapes of the message arrows are simplified. Reasoning:
> this makes the diagram clearer by reducing the number of visual
> elements and also makes more room for the contents (33).
I like that. I'll need to adjust the other figures to follow this convention.
Is there any well-known name for this shape other than "arrow"?
> My goal here is to put enough information in the diagram so that even
> a casual reader whose eyes happen to land on the figure while skimming
> over the document has a decent chance of figuring out the story, and
> may then be enticed to read the details in the text.
> These 1-vat and 2-vat figures shade the stack and queue areas of the
> vat. If it's really necessary for Springer the shading could be
> removed and replaced with partition lines, but shading is a better
> option when possible since the extra lines generate unnecessary visual
> clutter and line crossings.
I have no idea what's really necessary for Springer, but I just don't find the
lines David put in (as seen in the current draft of figure 1) to add
significant clutter. This minor degree of clutter removal isn't work risking a
Historical: One reason I'm being strict about Springer's guidelines is that
they basically destroyed the printed version of Paradigm Regained in an
attempt to reformat it. The first clue I had that they were doing a wholesale
reformatting of the document was when I received the paper proceedings. They
obviously did a lot of guesswork along the way, but never once did they try to
resolve a question by simply asking me.
Text by me above is hereby placed in the public domain
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