On 11 Mar 2014, at 10:19, Cl�ment Bera <bera.clement@gmail.com> wrote:

Hello,

[ Note: So in the default Pharo the method is named #sort: not #sortByProp: or #sortBy: but it's a detail ]

Yes, my mistake, I was misguided by #isSortedBy:

Now #sortByProp: is my own example method that accepts a block and executes it for each sortable item and then the result is compared.

I don�t like the idea to implement #value:value: for a symbol because it caries a bit of a logic inside it.

Uko

I like this idea because I also have always the problem. So I would like to be able to do:

projects sort: #creationDate

The implementation would be, in a similar fashion to how Symbol>>value: is implemented for aCollection collect: #isPlague :

Symbol>>value: val1 value: val2
^ (val1 perform: self) <= (val2 perform: self)

Then :

(#( 10 42 31 23 90 87 65) collect: #asValueHolder) sort: #value

Answers:

an Array(a NewValueHolder[ 10 ] a NewValueHolder[ 23 ] a NewValueHolder[ 31 ] a NewValueHolder[ 42 ] a NewValueHolder[ 65 ] a NewValueHolder[ 87 ] a NewValueHolder[ 90 ])

which is correct :-).

However I do not like:

projects sort: [ :proj | proj author birthDate ]

If you allow that where is the limit to the thing you want to allow ? In addition, I do not see any nice implementation and you could just implement in project

Project>>authorBirthDate
^ self author birthDate

Best,

Clement

2014-03-11 9:19 GMT+01:00 Yuriy Tymchuk <yuriy.tymchuk@me.com>:

Hi guys.

This is a thing that I encounter quite often.

Eg I have a collection of projects and I want to sort them by creation date. It would be nice to be able to do something like:

projects sortByProp: #creationDate

or by birth date of the author

projects sortByProp: [ :proj | proj author birthDate ]

Maybe I�m wrong, but as I�ve told already I encounter it quite often and writing something like

projects sortBy: [ :prev :next | prev creationDate <= next creationDate ]

is boring for me.

Cheers.
Uko