I don't see where are we willing to arrive at. '' asNumber gives zero in several other Smalltalks (Dolphin and VW, for example) and used to work as Mariano mentions in earlier versions of Pharo (which makes me surmise is the way Squeak worked as well).
So attempting addressing Nicolas point: the context where '' can be expected is when reading text from some other source (mainly text from a file) into you Pharo application. A library API has to have a reasonable balance between an excruciating "conceptual right" set of calls and the "principle of minimum surprise" for the corner cases in general. From this discussion, are we saying that for now on in order to have strings converted into numbers if we want to have the behaviour '' returning zero we shall change from '' asNumber to '' asNumberOrZero and this method will call a more general method like this? Number>>asNumberOrZero ^self asNumberOr: 0 And Number>>asNumberOr: aNumber ^Number readFrom: self ifFail: [^aNumber] Just my .0199999.... Em 20/10/2009 05:26, Stéphane Ducasse <[email protected]> escreveu: > I like asNumberOrZero we could have asNumberOr: aNumber so that we > are not bound to Zero and I would include it. Now what the others > think? Stef > On Oct 20, 2009, at 4:31 AM, Nicolas Cellier wrote: > > > 2009/10/20 Mariano Martinez Peck : > >> > >> On Mon, Oct 19, 2009 at 10:33 PM, Nicolas Cellier wrote: > >>> Yes, I understand the paradigm, nil is nothing is zero, empty is > >>> nothing is zero... But frankly, do you think '' forms a valid > >>> Number ? In every context ? So yes, this is expected, and can > >>> break compatibility, but sometimes this is necessary. > >>> If you want to keep this behaviour, you have to use an explicit > >>> rule like: asNumberOrZero ^Number readFrom: self ifFail: [^0] > >>> > >> Thanks Nicolas. Now, the question is, do you think we can create > >> this method in String as part of Pharo core? or I should add it > >> to my application? > >> cheers > >> mariano > >> > > Depends if the pattern was used by many packages or not... It > > would be stupid to create 10x the same extension to work around a > > pharo change. Would it be a temporary helper subject to > > deprecation, or a definitive feature ? I can't tell, and i don't > > decide, i only suggest. > > Nicolas > > > >>> Hope this helps... > >>> Nicolas > >>> 2009/10/20 Mariano Martinez Peck : > >>>> Hi folks: In older images, like 10418, '' asNumber gave me a 0 > >>>> (zero). But now, I get a 'Reading a number failed'. > >>>> Is this expected? > >>>> Perhaps it is due to the fix to this bug: > >>>> > >>>> http://code.google.com/p/pharo/issues/detail?can=1&q=1258&colspec=ID%20Type%20Status%20Summary%20Milestone&id=1258 > >>>> any toughs? > >>>> best > >>>> Mariano _______________________________________________ Pharo-project mailing list [email protected] http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project
