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 > 2013/7/25 Stéphane Ducasse <stephane.duca...@inria.fr> > 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 >> <stephane.duca...@inria.fr> 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 <bera.clem...@gmail.com> wrote: >> >>> This is because of compilation optimization. >>> >>> 2013/7/22 Stéphane Ducasse <stephane.duca...@inria.fr> >>> 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 > >
