Hi,

Christoph – great to hear that you also ran into this issue and have
already proposed a very similar fix (your fix even being a bit more
'correct' than mine, since it avoids sending the class message)!

Eliot – thank you for your insights. If I'm not mistaken, your proposed
solution would add additional restrictions to objects as methods (OAMs)
during simulation and debugging. This is because OAMs are more flexible
than CompiledMethods: For example, unlike a CompiledMethod, an OAM does not
have a fixed number of arguments it can respond to. Take a look at the
following OAM that responds to a message send with the number of arguments
sent:

run: selector with: arguments in: aReceiver
    ^ arguments size

The proposed wrapper class would not be able to adequately respond to the
numArgs message for this OAM.

I personally also don't feel like adjusting a single method inside the
simulator by adding a check for OAMs would "litter the simulation code".

Best,
Christian

Am Do., 22. Okt. 2020 um 19:28 Uhr schrieb Thiede, Christoph <
Christoph.Thiede at student.hpi.uni-potsdam.de>:

> Hi Christian, hi all,
>
>
> I already implemented the simulation of objects as methods in Kernel-ct.1339
> (Inbox). It has been working fine for me since February - we only need to
> get things like this merged sooner to prevent everyone from reinventing
> the wheel. :-)
>
>
> Best,
>
> Christoph
> <http://www.hpi.de/>
> ------------------------------
> *Von:* Squeak-dev <squeak-dev-bounces at lists.squeakfoundation.org> im
> Auftrag von Eliot Miranda <eliot.miranda at gmail.com>
> *Gesendet:* Mittwoch, 21. Oktober 2020 16:59:06
> *An:* The general-purpose Squeak developers list
> *Betreff:* Re: [squeak-dev] Debugger / Simulator cannot simulate (some)
> objects as methods
>
> Hi,
>
> > On Oct 21, 2020, at 6:09 AM, cmfcmf <cmfcmf.flach at gmail.com> wrote:
> >
> > Hi,
> >
> > when using simple objects as methods, the simulator (and therefore the
> > debugger also) raises an error if the object used as method does not
> > implement certain methods from CompiledMethod (e.g., numArgs). If such
> code
> > is debugged, the debugger opens a never-ending stream of error windows.
> >
> > I am under the (possibly wrong) assumption that objects as methods should
> > _not_ need to implement the complete CompiledMethod protocol to be
> > compatible with simulation and debugging.
>
> Since the only gap that needs filling is from the retrieval of the object
> from the method dictionary to the send of run:asMethod:withAruuments: (or
> whatever the actual selector is) let me suggest that you create a wrapper
> class whose instances hold on to an object to be run as a method and the
> selector and argument count and respond to the required CompiledCode
> protocol.  Then modify the simulator at the point where it gets the result
> of the message lookup from the dictionary and wraps the result in one of
> these if it is neither CompiledCode (isCompiledCode) not nil. We don’t want
> to litter the simulation code with checks and the wrapper approach has the
> best chance.
>
> Of course another test will be needed before a new contest is created, and
> maybe one test at the top of the tryPrimitive: method.
>
> >
> > I have attached a failing test called Context2Test that uses the
> simulator
> > to simulate a call of an object as method. You can also see the
> > "never-ending stream of error windows" by placing a "self halt" at the
> top
> > of the test and then stepping through the first assertion using the
> "over"
> > button. WARNING: Might make your image unusable.
> >
> > The root cause is the Context >> #send:to:with:lookupIn: method which
> > assumes that all methods are CompiledMethods. I have attached a simple
> fix
> > that works great for me – let me know what you think about it.
> >
> > Best
> > Christian
> >
> > Context2Test.st <http://forum.world.st/file/t372201/Context2Test.st>
> > Context-sendtowithlookupIn.st
> > <http://forum.world.st/file/t372201/Context-sendtowithlookupIn.st>
> >
> >
> >
> > --
> > Sent from: http://forum.world.st/Squeak-Dev-f45488.html
> >
>
>
>
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