From: Clemens Wyss <wys@...>
Date: 2001-11-13T17:28:55+09:00
Subject: [ruby-talk:24988] Re: Linux Magazine article

> Disclaimer: I also don't know LISP or Smalltalk, so I don't
> know whether similar things exist there (though I wouldn't
> be surprised).


Smalltalk does it (blocks [], iterators), too ;-)
e.g.:

'myCollectionObject forEachDo: [ :element | ... ]'

And the implementation of the 'forEachDo:' method might be

'forEachDo: aBlock
   elements do: [ :element | aBlock value: element ]'

A 'non iterating example' w.o. exception handling:
'open: fileName mode: aMode do: aBlock
    fh := File open: fileName mode: aMode.
    aBlock value: fh.
    fh close'

Note:
- Smalltalk blocks are Ruby's BlockClosures
- value: is Ruby's call
- 'do:' is THE iterator method of Collection classes.
- Smalltalk (as Ruby) also has detect:, select:, inject: ,...

Pretty sure matz has "taken" these concepts from Smalltalk ;-)

I(coming from Smalltalk and still loving Smalltalk, too) must also admit 
that 'Block(Closure)s' are one of the many attractions of Ruby.

Other Ruby highlights:
- pure OO
- "open classes"
- mixin-mechanism (Modules)
- very strong introspection/reflection mechanisms
- eval ;-)
- matz and the other bright and friendly 'gurus' of ruby-talk/c.l.r.

Regards

Clemens