From: Rodrigo Rosenfeld Rosas <rr.rosas@...>
Date: 2011-06-18T00:07:51+09:00
Subject: [ruby-core:37200] Re: Surprised by Array#delete_if in Ruby 1.9.2

I agree the name is confusing, specially because it doesn't seem to give 
any hints on return values.

Maybe it should be aliased as Array#without if the return value is 
expected, but indeed it wouldn't state in the name that the array itself 
would be modified. Maybe Array#without! should be used instead but I 
still think it is confusing...

I don't think that returning the deleted items would be any better for 
the method name though...

I can't give any suggestions for these method names right now, but I do 
agree with you that these names are very confusing.

Best regards, Rodrigo.

Em 17-06-2011 12:00, Mike Leddy escreveu:
> Hello,
>
> Being familiar with the use of Array#delete and Array#delete_at which return
> the item deleted I was somewhat surprised by the behaviour of Array#delete_if
> returning the resultant array and NOT an array of the items that were deleted.
>
> I would like to argue that it should return the items that are deleted:
>
> + Maintain similarity with Array#delete, and Array#delete_at "principle of
>    least surprise"
> + To really be the complement of Array#keep_if which "correctly" returns
>    the array that is 'kept'.
> + Writing code that achieves the same effect is a little difficult to read
>    and requires another variable (using parallel assignment +
>    Enumerator#partition) eg:
>
>      b, a = a.partition {|x| x%2==0}
>
> Anyone else agree ?
>
> Thanks,
>
> Mike
>
>
>
>
>