Not too sure which version of Pharo youâre using (image itâs 3) but Marcus recently mentioned a similar issue.
In Opal to remove the usage of #==, I removed it from the special selector array in the method: IRBytecodeGenerator class>>specialSelectorsArray ^ #(#+ 1 #- 1 #< 1 #> 1 #<= 1 #>= 1 #= 1 #~= 1 #* 1 #/ 1 #\\ 1 #@ 1 #bitShift: 1 #// 1 #bitAnd: 1 #bitOr: 1 #at: 1 #at:put: 2 #size 0 #next 0 #nextPut: 1 #atEnd 0 #== 1 nil 0 #blockCopy: 1 #value 0 #value: 1 #do: 1 #new 0 #new: 1 #x 0 #y 0)
Then I ran: IRBytecodeGenerator initialize. OpalCompiler recompileAll.
I looked in Pharo 3 image and tried the changes below: OCASTTranslator class>>initialize (removed line referring to the selector and then re-initialise) and then RBMessageNode>>isInlineIfNil (removed the reference to the selector so not picked up as inlined) Then try recompile: OpalCompiler recompileAll. Everything recompiles but then image dies so couldnât test it so I might be on wrong path ;) On 23 Jan 2014, at 5:51 AM, Alejandro Infante <alejandroinfante91@gmail.com> wrote: Actually looking at the bytecode, it is inlined. I performed this little experiment: MyClass>>foo MyNullClass new ifNil: [ Transcript show: 'Nil';cr ] ifNotNil: [ Transcript show: 'NotNil';cr ] So what it really does is MyNullClass new == nil ifTrue: [ Transcript show: 'Nil';cr ] ifFalse: [ Transcript show: 'NotNil';cr ]. (Well, the #ifTrue:ifFalse: is also inlined) So actually subclassing UndefinedObject doesn't work either, because of the #==. Also I think (I'm not completely sure about this), the #== doesn't perform a lookup and the VM takes care of that, so there is no way to change it's behavior by overriding it. About how to workaround... I have no idea =( Cheers, Alejandro 2014/1/22 Sean P. DeNigris <sean@clipperadams.com> I'm missing something here... I tried implementing: MyNullClass>>#ifNil: nilBlock ifNotNil: notNilBlock nilBlock value. But the notNilBlock is evaluated. I'm assuming it's being inlined. Is that right? How do I workaround? I also tried subclassing UndefinedObject, with the same result. Any ideas? ----- Cheers, Sean -- View this message in context: http://forum.world.st/Null-Object-Pattern-tp4738574.html Sent from the Pharo Smalltalk Developers mailing list archive at Nabble.com.