On Sun, 25 Mar 2018, Chris Cunningham wrote:

> 
> 
> On Mar 25, 2018 2:46 PM, "Levente Uzonyi" <leves at caesar.elte.hu> wrote:
>       On Sun, 25 Mar 2018, commits at source.squeak.org wrote:
>
>             Chris Cunningham uploaded a new version of Kernel to project The Trunk:
>             http://source.squeak.org/trunk/Kernel-cbc.1163.mcz
>
>             ==================== Summary ====================
>
>             Name: Kernel-cbc.1163
>             Author: cbc
>             Time: 21 March 2018, 9:09:20.773568 pm
>             UUID: 45d9dad8-7c81-034e-b578-b9ccd291cab6
>             Ancestors: Kernel-dtl.1162, Kernel-fn.1152
>
>             Update #xor: to work with argument being a block as well.
>
>             =============== Diff against Kernel-dtl.1162 ===============
>
>             Item was added:
>             + ----- Method: Boolean>>xor: (in category 'logical operations') -----
>             + xor: aBoolean +       "Exclusive OR. Answer true if the receiver is not equivalent to aBoolean."
>             + +     ^(self == aBoolean) not!
> 
> 
> Why not just
> 
>         ^self ~~ aBoolean
> 
> Because that lets you xor between Boolean and other a
> Odd stuff. Meaning bugs can creep in without any errors being raised. 

Am I missing something? Is there a case when [a~~b] and [(a==b)not] 
yield different results where a and b can be any object?

Also, this method is overridden in all subclasses, isn't it?

> Yes ~~ is faster - but xor: is already fast. 

It's not about speed. It's about unnecessary complexity.

Levente

>
>       ?
> 
>
>             Item was changed:
>              ----- Method: False>>xor: (in category 'logical operations') -----
>              xor: aBoolean
>             +       "aBoolean is either a boolean, or an object who's #value returns a boolean (usually a block)."
>             +       ^aBoolean value ifTrue: [ true ] ifFalse: [ false ]!
> 
> 
> I think the parameter should have a better name, because the #value send doesn't make much sense when you read the code.
> 
> I guess so. 
>
>       Levente
>
>             -       "Posted by Eliot Miranda to squeak-dev on 3/24/2009"
>             - -     ^aBoolean!
>
>             Item was changed:
>              ----- Method: True>>xor: (in category 'logical operations') -----
>              xor: aBoolean
>             +       "aBoolean is either a boolean, or an object who's #value returns a boolean (usually a block)."
>             +       ^aBoolean value ifTrue: [ false ] ifFalse: [ true ]!
>             -       "Posted by Eliot Miranda to squeak-dev on 3/24/2009"
>             - -     ^aBoolean not!
> 
> 
> 
> 
>