[comp.lang.smalltalk] Class Pen in PPS Rel. 4

peskin@caip.rutgers.edu (R. L. Peskin) (10/27/90)

We are currently evaluating the new ParcPlace Systems Rel. 4 of Smalltalk. We 
are porting our  scientific graphics package (SCENE) to this version. (Previous 
versions of SCENE for PPS Smalltalk were monochrome only; the color version was 
done in Tektronix Smalltalk. There is also a Smalltalk/V Mac version in 
progress.) While there are many features we like in Rel. 4 (color, native 
windows, etc.), there is no class Pen!

ParcPlace tells us that they consider the Pen obsolete since their data 
indicated that it was not really used. I personally disagree. Pen was not just 
a toy to scribble with; it is a serious tool for experimental geometry, etc. 
when used in TurtleGraphics. I'm interested in others reaction to the loss of 
class Pen in Rel. 4. One point to be made is that the better books (Inside 
Smalltalk for example) discuss the Pen, and potential new Smalltalk users may 
be discouraged if it not really in the system.

By the way our SCENE system needs Pen and we are implementing it, and we will 
make it available on the net.

--dick peskin


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 Richard L. Peskin     CAIP Parallel Computing Lab                      
 CAIP Center CN - 1390  Rutgers University       
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         net: peskin@caip.rutgers.edu              
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mst@vexpert.dbai.tuwien.ac.at (Markus Stumptner) (10/27/90)

From article <Oct.26.17.51.59.1990.12368@caip.rutgers.edu>, by peskin@caip.rutgers.edu (R. L. Peskin):
 
> ParcPlace tells us that they consider the Pen obsolete since their data 
> indicated that it was not really used. I personally disagree. Pen was not just 
> a toy to scribble with; it is a serious tool for experimental geometry, etc. 
> when used in TurtleGraphics.

I agree.  I would like to know where those data came from.  Did they
really look at greater amounts of customers' code?  What also strikes
me as odd is the use of the word 'obsolete'.  I haven't seen R4 as
yet.  Did they introduce anything new to take the place of Pens (e.g.,
provide similar functionality)?

> One point to be made is that the better books (Inside 
> Smalltalk for example) discuss the Pen

I don't think this is a coincidence; Pens (and turtle graphics) are
great stuff for tutorials.  Smalltalk is not that easy to learn, and I
think removing Pens is a step backward in that respect.

I think it would have been fitting if the class had been included as a
file-in.  After all, this way has been used in the past to keep
useful, but not always necessary functionality (e.g., statistics) out
of the basic image.  

Markus Stumptner                                mst@vexpert.dbai.tuwien.ac.at
Technical University of Vienna                  vexpert!mst@uunet.uu.net
Paniglg. 16, A-1040 Vienna, Austria             ...mcsun!vexpert!mst

pieter@prls.UUCP (Pieter van der Meulen) (10/30/90)

peskin@caip.rutgers.edu (R. L. Peskin) writes:

>ParcPlace tells us that they consider the Pen obsolete since their data 
>indicated that it was not really used. I personally disagree. Pen was not just 
>a toy to scribble with; it is a serious tool for experimental geometry, etc. 

Assuming your information is correct (I can hardly believe it), then I
wonder what "data" they used. For one, our software (1.5MByte, 30Klines)
uses (sub-)class Pen heavily. However, if their motivation to remove Pen is
be that vector-graphics is platform-dependent (e.g. native window support for
color-pen drawings), then I can "sort-of" understand it. Still, Pen as an
example-Class should remain. Or, keep it as a fileIn for backward-
compatibility.... wait, I already have said that many times and it seems
to have the opposite effect :-(

By the way, how is Digitalk treating you guys with respect to new releases
and backward-compatibility of Smalltalk-V?

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