A few random comments from an eToy newbie

Alan Kay Alan.Kay at squeakland.org
Mon Apr 7 20:54:23 UTC 2003

Hi --

At 12:20 PM -0700 4/7/03, Ned Konz wrote:
>On Monday 07 April 2003 11:13 am, Alan Kay wrote:
>>  There are no nil variables, all variables have some concrete object
>>  in them, and there is a rudimentary type system (which needs to be
>>  done better).
>But this is inconsistent and confusing from a user point of view.

Why? There is an object of some kind in every variable. E.g. numeric 
variables start with a "5" or something. What's inconsistent about 
it? More interesting, why do children find this to be quite 
consistent? The kind of object the variable is willing to hold can be 
changed with the menu on each variable line in the viewer.

>* Make a new Holder. You don't see anything in it. Its cursor is at 1.
>* Then run a script that does:
>	Holder includeAtEnd Holder's firstElement
>Now you see a dot in it, but its cursor is still at 1. From a
>programmer/scripter point of view, the "before" and "after" states
>are the same. However, the Holder *looks and acts* different: there
>is now a dot in it that can be viewed and grabbed, while before there

The Holder isn't a variable (but perhaps it should be). But the 
behavior you describe sounds like a bug. The variable 
"playerAtCursor" seems to hold the default player called "dot", so 
perhaps we should see it in the holder (Scott?)

>>  SketchMorphs shouldn't ignore the grid (and they don't on my
>>  version of Squeak). What's going on here?
>Grab a Playfield from the flaps. Set its grid to something big
>(perhaps 30 or so). Make a SketchMorph. Drop the SketchMorph on this
>Playfield. It doesn't snap to anything. However, if you use the brown
>halo handle, it does snap to the grid. As does the yellow handle.

Sounds like a bug that has crept in recently.

>>  Also, I think that one of
>>  the original conventions was supposed to be "center of object on
>>  grid intersection".  Maybe Scott or Dan has some comments.
>That sounds like a good idea, though it's inconsistent with the
>behavior of the PolygonMorph (which snaps its *origin* to the grid

Blame Dan, heh heh. But the default should be the center even though 
this doesn't work for all cases.



>Ned Konz


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