[ST-72] Bug when edit factorial
Stephane Ducasse
ducasse at iam.unibe.ch
Tue Jun 10 13:49:07 UTC 2003
Thanks this was the smell I got reading the code (feeling like in
Scheme).
> "The
> Early History of Smalltalk" by Alan Kay:
I should reread it.
Stef
On Tuesday, June 10, 2003, at 03:34 AM, Jecel Assumpcao Jr wrote:
> On Monday 09 June 2003 17:37, Stephane Ducasse wrote:
>> Now I have some questions:
>> - why the turtle has primitives and cannot simply be defined in
>> ST-72
>
> They could, but the performance would not be acceptable. Remember that
> as a Logo successor Turtle Graphics had to be a very usable part of the
> language.
>
>> - I thought that to was to create classes, but the fils AllDefs
>> use it to for read, print.... I'm confused. I will have to reread the
>> bootstrap
>
> I'll quote the bottom of page 20 (p. 78 in the proceedings) of "The
> Early History of Smalltalk" by Alan Kay:
>
> One of the styles retained from Smalltalk-71 was the comingling of
> function and class ideas. In other works [should be words?],
> Smalltalk-72 classes looked like and could be used as functions,
> but
> it was easy to produce and instance (a kind of closure) by using
> the
> object ISNEW. Thus, factorial could be written "extensionally" as:
>
> to fact n (^if :n=0 then 1 else n*fact n-1)
>
> or "intensionally", as part of class integer:
>
> (.... %! ?(^:n=0 ?(1) (n-1)! )
>
> Of course, the whole idea of Smalltalk (and OOP in general) is to
> define everything intensionally. And this was the direction of
> movement as we learned how to program in the new style.
>
> I imagine that "read" and "print" (and "to" itself) represent the early
> style.
>
> -- Jecel
>
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