Ok by digging a bit, i found that it was a problem in my behavior though i don't understand it.
When sending message to self, the #isMetaMessage: returns always true when evaluating the first test condition GHCurrentMetaLevelDepth value > 0 ifTrue: [ ^true ]. The value returns something higher than 0 and my "self messages" are considered to be meta-messages. It is very sensible to modifications, as just removing this test or try to bend it can freezes the image (just tried to see what would happen). I'm a bit lost, what should i do to consider "self messages" not "meta" in the behavior ? Le 2016-07-28 12:33, Steven Costiou a écrit : > Hi, > > I think i am missing something. > > For example in the following code (took from the tests): > > | victim virus actual | > virus := GHObjectVirus behaviour: GHGhostBehaviourStub new. > > victim := 0@0 corner: 3@4. > virus infect: victim. > victim corner > > The evaluation is trapped by the send:to: method in the behavior (i've put a > halt there). However if i replace the "corner" message by an inspect of the > victim, and if i evaluate "self corner", then the message is processed > without going through the send:to: method of the behavior. It is not halted > and the victim responds immediately to the message. I have also tried to add > a new method in the Rectangle class that calls "self corner". When called in > the playground, my new message is trapped but not the "corner" sent to self. > > From what i understand it could be related to the behavior i use, but i don't > see what's missing. > > Le 2016-07-28 11:35, Denis Kudriashov a écrit : > I think I not understood second part of "self problem" in this paper. But > self sends are covered by virus as I described. > > 2016-07-28 11:30 GMT+02:00 Denis Kudriashov <dionisi...@gmail.com>: > > Hi > > 2016-07-27 22:19 GMT+02:00 Steven Costiou <steven.cost...@kloum.io>: > > Hi, > > I use virus from Ghost to intercept messages sent to a given object and adapt > methods behaviors for this particular object only. However it would seems > that doing interception this way is subject to the "self problem" described > in this paper from Stéphane (DUCASSE, Stéphane. Evaluating message passing > control techniques in Smalltalk. _JOURNAL OF OBJECT ORIENTED PROGRAMMING_, > 1999, vol. 12, p. 39-50). > > I understand i could do instance based adaptation using an other technique, > but i wonder if there is any way with Ghost to deal with this "self problem" > problem ? I think "self problem" is only related to classic proxies when > objects stay behind them. But ObjectVirus is not proxy in this meaning. When > you infect your object by virus it is not replaced by somebody else. It is > same original instance but with overridden behaviour. That's why I call it > virus without any relation to proxies. > Any message to infected object is processed by your behaviour. All self sends > are intercepted. But there are few exceptions: > - special messages like ==,ifTrue/ifNil are not intercepted > - meta messages are not intercepted. They processed by Ghost mechanics but > they not passed to your behaviour. Meta messages defined by #currentMetaLevel > of your behaviour. You could implement it like: > > YourGhostBehaviour>>currentMetaLevel > ^GHMetaLevel empty > > Empty meta level means that all messages will be passed to your behaviour. > There is also "GHMetaLevel standard" which is default one. It makes most of > "tool messages" not interceptable. For example #printString, #class, > #instVarAt: will be not intercepted. It's messages which are usually used by > tools like inspector and debugger. > Standard meta level simplifies debugging of new behaviours. If you make > mistake somewhere standard messages will be not broken and you could debug > error by tools. -- kloum.io
