[Pharo-users] Use cases for methods with optional parameters

phil at highoctane.be phil at highoctane.be
Fri Jan 22 03:00:16 EST 2016


This would be nice to be able to use several different languages "ways of
doing things" that would translate into message sends behind the scenes.

Helvetia story...

Phil

On Thu, Jan 21, 2016 at 6:04 PM, Esteban A. Maringolo <emaringolo at gmail.com>
wrote:

> 2016-01-21 8:38 GMT-03:00 Henrik Johansen <henrik.s.johansen at veloxit.no>:
> >
> >> On 20 Jan 2016, at 6:14 , Esteban A. Maringolo <emaringolo at gmail.com>
> wrote:
> >>
> >>
> >> I would be interested in the use cases and how to deal with
> >> "undefined" arguments, will they be nil or other kind of undefined
> >> object?
>
> > Perhaps
> >
> > request: aFile with: anotherThing and: aThirdThing
> >         <optionalParameter: anotherThing "default: nil">
> >         <optionalParameter: aThirdThing default: defaultThirdThing>
> > ->
> > request: aFile with: anotherThing
> >         ^self request: aFile with: anotherThing and: self
> defaultThirdThing
> > request: aFile and:: aThirdThing
> >         ^self request: aFile with: nil and: self aThirdThing
> > request: aFile
> >         ^self request: aFile with: nil and: self defaultThirdThing
>
>
> The pragma for the default unless it's a literal object it should be a
> message send.
>
> I still have to see a good use case that could justify the use of
> that. Because it also involves the message lookup, which AFAIK is
> performed by the VM.
>
> Regards,
>
> Esteban A. Maringolo
>
>
>
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