2008/11/28 Keith Hodges <keith_hodges at yahoo.co.uk>:
>
>>>
>>> In terms of code smells, this is chemical warfare!! :-D.
> I must admit I am having second thoughts!
>> No doubt about this. Kids, don't try this at home.
>>
>> It still tremendous fun that you can do it. Keith, I have no idea what
>> you need this for but I think the following is pretty complete - it
>> skips until the next pop bytecode which marks the end of the current
>> statement. It should get confused only if there was a block in that
>> line that had a pop in itself:
>>
>> send
>>     Transcript show: 'send '.
>>     self returnToPop.
>>     self neverReached
>>
>> returnToPop
>>     | ctxt |
>>     ctxt := thisContext sender sender.
>>     [ctxt nextByte = 135]
>>         whileFalse: [ctxt jump: 1].
>>     ctxt resume
>>
>> Try filing in attachment and eval "Evil new test"
>>
>> - Bert -
> Thats really cool, thanks! It gives me a warm fuzzy feeling just to know
> we can do it.
>
> In the Logging framework, the message eating Null WAS used to disable
> logging features.
>
> so for example the call...
>
> self log info mysql dumper: theDataReturned asSuitableFormat.
>
> A) to disable the #info level log messages -> MyLogRouterPolicy-#info ^null
> B) to disable the #mysql category log messages ->
> MyLogRouterPolicy-#mysql ^null
> C) to disable all Logging, and even remove the Logging framework
> completely. Object-#log ^null
>
> Realizing that some user code may take a lot of time, #asSuitableFormat
> in this example, I began looking for alternative solutions. (hence the
> question)
>
> Instead of using null as a hammer, I implemented an explicit #isIgnore
> flag which covers most use cases. (It still cannot cover the case where
> no Logging framework is loaded at all)
>
> My solution is as follows:
>
> self log info mysql use: [
>
>    self log dumper: theDataReturned asSuitableFormat
>
> ].
>
> I have a personal convention #use: is my version of #in: which is a bit
> more flexible, I use it like this e.g.
>
> To ensure streams close:
>
>  FileStream-#use: ^ [ aBlock value: self ] ensure: [ self close ].
>
> To provide psuedo null behaviour (equivalent of ifNotNilDo:)
>
> UndefinedObject-#use: aBlock ^ self
>
> So...
>
> LogRouter-#use: aBlock
>
> isIgnore ifFalse: [ aBlock value ]
>
> This allows a user to disable mysql Logging by implementing
>
> MyLogRouterPolicy-#mysql ^ self ignore
>
> With this solution I am almost happy. It is cleaner, and allows whole
> chunks of logging code to be skipped if the user simply sets part of
> their LoggingPolicy to self ignore.
>
> So, we can now spit chunks of verbose logging code without being afraid
> of slowing things down for someone else, since we know that any user is
> in complete control via their chosen LogRouterPolicy
>
> However, after this I dont think I can resist releasing "SuperNull"
> sometime soon.
>
> thanks for an interesting insight,
>
> Keith
>
>

A shorter form of:

  self log info mysql use: [

    self log dumper: theDataReturned asSuitableFormat

 ].

Could be:

   self log info mysql dump: [ theDataReturned asSuitableFormat ]

-- 
Best regards,
Igor Stasenko AKA sig.