Smalltalk › Squeak › Squeak - Dev

pipe

_‹ Previous Topic Next Topic _›

Classic

List

Threaded

4 messages Options

Levente Uzonyi-2

pipe

> Fabio's proposal:
>
> make the ";" cascade operator send the message not the the previous
> receiver but to the object returned by the previous message send.

This would break most code with cascades, like:

o add: 1; add: 2; yourself.

Pipes might be useful in some cases, so one can add the following
message to Object:

pipe: aBlock

| catcher pipedObject |
catcher := MessageCatcher new
privAccumulator: OrderedCollection new.
aBlock value: catcher.
pipedObject := self.
catcher privAccumulator do: [ :each |
pipedObject := each sendTo: pipedObject ].
^pipedObject

Then simply use ; as a pipe like:

1 pipe: [ :mock |
mock + 3;
- 2;
asFloat;
* 2;
asString;
, ' foo';
, ' or bar';
first: 10 ]

Fabio Filasieno

Re: pipe

On Aug 25, 2007, at 7:35 PM, [hidden email] wrote:

pipe: aBlock

| catcher pipedObject |
catcher := MessageCatcher new
privAccumulator: OrderedCollection new.
aBlock value: catcher.
pipedObject := self.
catcher privAccumulator do: [ :each |
pipedObject := each sendTo: pipedObject ].
^pipedObject

Thanks leves ... :-) ...! You rock !

I didn't know about the MessageCatcher.

Really really close .... as this fails.

| collection |

collection := OrderedCollection new.

collection add:10; add:20; add:30.

10 pipe: [:item | item + 1 ; + 1; > 10 ; ifTrue: [#True] ifFalse:[#False] <- No special messages expected ->]

Fabio

Levente Uzonyi-2

Re: pipe

On Sun, 26 Aug 2007, Fabio Filasieno wrote:

> Thanks leves ... :-) ...! You rock !
> I didn't know about the MessageCatcher.
>
> Really really close .... as this fails.
>
> | collection |
> collection := OrderedCollection new.
> collection add:10; add:20; add:30.
> 10 pipe: [:item | item + 1 ; + 1; > 10 ; ifTrue: [#True] ifFalse:
> [#False] <- No special messages expected ->]
>
>
> Fabio
>
>
>

Some messages can not be cascaded, and special messages like
#ifTrue:ifFalse: can not be catched by MessageCatcher.
I don't know if other smalltalks have the same behavior, or not.
If MessageCatcher could catch messages like #ifTrue:ifFalse:, then one
could simply use the following workaround, even if the message can't be
cascaded:

10 pipe: [:item | item + 1 ; + 1; > 10. item ifTrue: [#True] ifFalse:
[#False] ]
(I know it breaks the "pipe theory" :))

Levente

Alan Kay

Re: pipe

But of course you can write your own version of a conditional that
will work fine ....

Cheers,

Alan

-----------

At 09:09 AM 8/26/2007, UZONYI Levente wrote:

>On Sun, 26 Aug 2007, Fabio Filasieno wrote:
>
> > Thanks leves ... :-) ...! You rock !
> > I didn't know about the MessageCatcher.
> >
> > Really really close .... as this fails.
> >
> > | collection |
> > collection := OrderedCollection new.
> > collection add:10; add:20; add:30.
> > 10 pipe: [:item | item + 1 ; + 1; > 10 ; ifTrue: [#True] ifFalse:
> > [#False] <- No special messages expected ->]
> >
> >
> > Fabio
> >
> >
> >
>
>Some messages can not be cascaded, and special messages like
>#ifTrue:ifFalse: can not be catched by MessageCatcher.
>I don't know if other smalltalks have the same behavior, or not.
>If MessageCatcher could catch messages like #ifTrue:ifFalse:, then one
>could simply use the following workaround, even if the message can't be
>cascaded:
>
>10 pipe: [:item | item + 1 ; + 1; > 10. item ifTrue: [#True] ifFalse:
>[#False] ]
>(I know it breaks the "pipe theory" :))
>
>
>Levente