Hi Fabio,


welcome to the list! I guess what you would express with pipes would
be written in Smalltalk like this?

(((obj collect: [ :x | …])
   filter: [:x | …] )
      select: [:x | …])

And with a pipe operator you would save a few parntheses here?

With unary message sends, the syntax gives you a kind of piping for
free, just chain the messages:

'abc' reverse first isVowel

With keyword messages the syntax is in favor of multiple keyword
message selectors:

'abc' detect: [:a | a isVowel] ifAbsent: ['']

is the message #detect:ifAbsent: and not a cascade of two messages
#detect and #ifAbsent.

Smalltalk syntax was deliberately designed to be simple, based on a
few mechanisms. By the way, your pipe idea is reflected in some
methods in the collection hierarchy:

Collection>>select:thenDo:
Collection>>select:thenCollect:


Cheers

Matthias

On 8/24/07, Fabio Filasieno <fabio.filasieno at gmail.com> wrote:
> II'm new at Smalltalk and I have a few questions.
> """Why smalltalk has no operator for piping ?""""
>
> obj collect: [ :x | …] | filter: [:x | …] | select: [:x | …] ?
>
> but has the `;` (cascade operator)?
>
> I don't care to send messages to the reciever of the previous
> message, because I return self when no return value is important; for
> instance ….
>
> point x: 10 | y: 20 | z: 30
>
> x returns self, y returns self, z returns self -> which is the
> updated point.
>
> works exactly as:
>
> point x:10;  y:20 ;  z:30.
>
> But you lose PIPES !!!!! Can somebody elaborate on this ?
>
> There might be cases where I'm returning a value and I wish to
> discard it and then send again to the previous receiver ... but I
> really don't like to loose the pipe for that ... since I can do that
> returning self.
>
> With Smalltalk ... we've got a homoiconic language and the system
> written in it self, a consistent language in everything, even the if-
> then-else that everybody else still don't get right; we've got the
> most wonderful programming experience of all, even better that Ruby/
> Python etc ...
>
> but why on earth we have the "cascade operator" instead of the
> PIPE ?????
> What I'm I missing ?
>
> I need the `|` to avoid parenthesis, and weird hacks ...
>
> Fabio
>