In business apps, the need for default values happen all the time, so the idiom has value (not sure for the message name though).
We could use��

x := [ self thing ] ifError: [ someDefault ]��

for these purposes. Triggering errors is not too nice still.

Now, what if self itself is nil or empty?

BTW, isEmptyOrNil exists in the image for Collections and UndefinedObject. Empty has no meaning for Object, so why test against empty in the name?

In the image, I see that we do have #default: anObject in several places. It seems to serve the same intent.

What is the idiom for such things in Pharo? Importing idioms from other languages works but if we do have one already, we will introduce confusion.


Phil



On Mon, Jan 5, 2015 at 1:19 PM, Tudor Girba <tudor@tudorgirba.com> wrote:
This is not about taste. This is about not promoting the use of nil or dependency or the meaning of empty collection.

A better way is to look at the upstream logic and modify that one so that it does not need to know about nil or empty.

Cheers,
Doru



On Mon, Jan 5, 2015 at 1:17 PM, Sebastian Sastre <sebastian@flowingconcept.com> wrote:
taste is taste but would you care to illustrate your point with examples?
I���m curious about it



> On Jan 5, 2015, at 6:12 AM, stepharo <stepharo@free.fr> wrote:
>
> You summarise well the kind of code I do not like.
> isNil everywhere and horrible tests.
>
> Stef
>
>
> Le 4/1/15 23:27, Sebastian Sastre a ��crit :
>> Hi guys,
>>
>> I���ve started to use this little one:
>>
>> Object>>ifNilOrEmpty: aBlock
>>
>>�� �� �� self ifNil: [ ^ aBlock value ].
>>
>>�� �� �� (self isCollection and: [
>>�� �� �� self isEmpty ]) ifTrue: [ ^ aBlock value ].
>>
>>�� �� �� ^ self.
>>
>>
>> It allows you to do the widely known JavaScript one-liner:
>>
>> var stuff = this.thing || ���some default value for when this.thing is undefined, null or an empty string���.
>>
>> but in smalltalk in this way:
>>
>> stuff := self thing ifNilOrEmpty: [ ���some default value for when self thing is nil or an empty string��� ]
>>
>> simple thing feels practical and nice :)
>>
>>
>>
>
>





--

"Every thing has its own flow"



--
---
Philippe Back
Visible Performance Improvements
Mob: +32(0) 478 650 140 | Fax: +32 (0) 70 408 027
Blog: http://philippeback.be | Twitter: @philippeback

High Octane SPRL
rue cour Boisacq 101 | 1301 Bierges | Belgium

Pharo Consortium Member -��http://consortium.pharo.org/
Featured on the Software Process and Measurement Cast -��http://spamcast.libsyn.com
Sparx Systems Enterprise Architect and Ability Engineering EADocX Value Added Reseller
��