:)
On Jul 25, 2013, at 1:20 PM, Guillermo Polito <[email protected]> wrote: > > > > On Thu, Jul 25, 2013 at 1:17 PM, Camille Teruel <[email protected]> > wrote: > > On 25 juil. 2013, at 13:12, Clément Bera wrote: > >> Perhaps you should add some value message so that the assertions are >> actually run, shouldn't you ? > > I always felt that e-mails lack an unsend command :D > > Or gmail quotes should work properly :P > > >> 2013/7/25 Stéphane Ducasse <[email protected]> >> For the people following I added a test to show the homeContext of a block >> >> >> | homeContext b1 | >> homeContext := thisContext. >> b1 := [| b2 | >> self assert: thisContext closure == b1. >> self assert: b1 outerContext == homeContext. >> self assert: b1 home = homeContext. >> b2 := [self assert: thisContext closure == b2. >> self assert: b2 outerContext closure outerContext == >> homeContext]. >> self assert: b2 home = homeContext. >> b2 value]. >> b1 value >> >> >> >> >>> >>> >>> On Tue, Jul 23, 2013 at 2:02 AM, Stéphane Ducasse >>> <[email protected]> wrote: >>> thanks! >>> It makes a lot of sense. >>> I will play with another example because I want to really understand the >>> outerContext of closure vs the home context. >>> >>> The outerContext is a link in the static chain. Each block is created >>> inside some context. This is the block's outerContext. If the block is >>> not nested then the outerCOntext will also be the home context But if the >>> block is nested inside another block activation, then the outerContext >>> refers to that block activation, and the block activation's block's >>> outerContext is the home context. So there are as many outerContext steps >>> as there are nesting levels. >>> >>> | homeContext b1 | >>> homeContext := thisContext. >>> b1 := [| b2 | >>> self assert: thisContext closure == b1. >>> self assert: b1 outerContext == homeContext. >>> b2 := [self assert: thisContext closure == b2. >>> self assert: b2 outerContext closure outerContext == >>> homeContext]. >>> b2 value]. >>> b1 value >>> >>> Ignore the "bN appears to be undefined at this point" and evaluate the >>> above. No assert fails. >>> >>> Draw a picture. >>> >>> >>> Stef >>> >>> On Jul 23, 2013, at 6:58 AM, Clément Bera <[email protected]> wrote: >>> >>>> This is because of compilation optimization. >>>> >>>> 2013/7/22 Stéphane Ducasse <[email protected]> >>>> Hi >>>> >>>> when I execute the following >>>> >>>> first >>>> "Bexp new first" >>>> | temp | >>>> temp := 2. >>>> [ temp. >>>> thisContext inspect.] value. >>>> ^ temp >>>> >>>> tmp in the inspector is nil and does not hold 2 and I was wondering why. >>>> I thought that thisContext was returning the blockContext >>>> In the outercontext of thisContext blockClosure, tmp is also nil. >>>> >>>> >>>> This is because here 'temp.' is evaluated for effect (the value is not >>>> stored anywhere) and it has no side effect (reading a variable cannot lead >>>> to a modification of state of another object). So the compiler removes it. >>>> As it is removed, it is the same as if it was not in the block. So the >>>> block cannot access temp. Now write 'temp:= #foo' or 'temp foo' you will >>>> get it. >>>> >>>> first >>>> "Bexp new first" >>>> | temp | >>>> temp := 2. >>>> [ temp. >>>> temp traceCr. >>>> thisContext inspect.] value. >>>> ^ temp >>>> >>>> output 2 on the transcript. >>>> >>>> In this case 'temp.' is still removed, but the value of temp still need to >>>> be copied in the block for ' temp traceCr.'.'temp traceCr' is also >>>> evaluated for effect, but has the side effect to output the transcript, so >>>> the compiler cannot remove it. >>>> >>>> Basically the is very few things that the compiler removes, and one of >>>> them is variable read for effect, because you are sure it cannot lead to >>>> any issue. >>>> >>>> Stef >>>> >>>> >>> >>> >>> >>> >>> -- >>> best, >>> Eliot >> >> > >
