Ahem...when I said "Collection protocol" in the second paragraph below I
meant, of course, "BlockContext protocol".

<blush>

[self writeUponBlackboard: 'I will proofread all messages *carefully* before
sending them' ] timesRepeat: 1000.

Bob Jarvis
Compuware @ Timken

> -----Original Message-----
> From:	Jarvis, Robert P. (Contingent) 
> Sent:	Wednesday, January 19, 2000 3:34 PM
> To:	'squeak at cs.uiuc.edu'
> Subject:	RE: (1 to: self) inject: 1 into: #*
> 
> There are a few issues here:
> 
> First, IMO this change just raises the obfuscation quotient.  I think it
> would make learning to use these messages harder for beginners as they'd
> have to learn two forms of the message, one using a block as the second
> argument and another using a symbol.  Even experienced Smalltalker's might
> have to stop and puzzle this out for a minute before they recognized what
> was going on.
> 
> Second, IIRC we went through an exercise a while back to get rid of
> message
> implementations in various classes which, while they were useful, served
> mostly as crutches and/or bandages for problems elsewhere in the image.
> (Someone else will have to chime in with specifics here, as I was only an
> observer of this process).  Slapping bits of Collection protocol
> (specifically #value:value:) into Symbol seems to me to be a step
> backwards
> in this regard.  
> 
> Third, this can produce slow-running code.  For example, if
> Integer>>factorial was implemented as you suggest it would run roughly
> twice
> as slowly as it does today.  Using your implementation below
> 
> 	Time millisecondsToRun: [ 500 factorial ]
> 
> answers 5137.  The standard #factorial method takes 2634 milliseconds to
> evaluate "500 factorial".  
> 
> To use the car salesman's adage, "Oh, sure, you can do that - but you
> wouldn't be happy with it...".  :-)
> 
> Bob Jarvis
> Compuware @ Timken
> 
> > -----Original Message-----
> > From:	Mats Nygren [SMTP:nygren at sics.se]
> > Sent:	Wednesday, January 19, 2000 2:05 PM
> > To:	Squeak
> > Subject:	(1 to: self) inject: 1 into: #*
> > 
> > Hello,
> > 
> > I find the following elegant:
> > 
> >   aCollection inject: 1 into: #*
> > 
> > (and similarly for all binary messages and single-keyword messages)
> > 
> > more so than the normal:
> > 
> >   aCollection inject: 1 into: [ :a :b | a * b]
> > 
> > For example like this:
> > 
> >   factorial
> >      (1 to: self) inject: 1 into: #*
> > 
> > The price for this seems to be simply:
> > 
> > !Symbol methodsFor: 'converting' stamp: 'mn 1/19/2000 19:38'!
> > value: i value: ii
> >    ^i perform: self with: ii! !
> > 
> > And similarly for unary messages
> > 
> >   aCollection collect: #negated
> > 
> > What do you think?
> > 
> > /Mats Nygren