Hi Marcus - that’s actually what I do - and “create” in this case, creates a
class and then restarts like the method case does.
I guess I was wondering if we can do it more cleanly and also improve the
debugger message.
If I’ve understood you guys correctly- you try to remove the ambiguity around
operations. Looking up a class and getting nil - seems like one of these holes
you keep sorting out.
I think the flaw in my solution is understanding if that message was being sent
to a class, or some other global? I dont think I got that bit right (but it’s
certainly better than nothing).
e.g. in the debugger I am doing (in DoesNotUnderstandDebugAction)
msg := self interruptedContext tempAt: 1.
(msg lookupClass == UndefinedObject ) ifTrue: [
^self createMissingClassIn: self interruptedContext ].
I’m not totally convinced that lookupClass has to be a class - although maybe
its good enough. But really, at the time this happened - we probably knew
better than to get a DNU debug action in the the first place - and equally the
title in the debugger could be something more akin to the kind of action its
supposed to be.
Anyway - this is all musing on my part - and I will assemble a proper PR for
review by you guys (and at least it advances us forward - and maybe opens the
door to better changes further on).
I’m just juggling another change at the moment - so it will be a few days.
Tim
Sent from my iPhone
> On 23 Aug 2018, at 05:33, Marcus Denker <[email protected]> wrote:
>
>
>
>> On 22 Aug 2018, at 16:24, Tim Mackinnon <[email protected]> wrote:
>>
>> Hi - but I guess my question is (and excuse my basic knowledge in this area)
>> - when a class isn’t found - can we do better than return nil so that the
>> debugger can give a better msg and presumably the code I’ve written could
>> live on that undefined object? Or am thinking about this wrong?
>
> In pharo7 we could easily do that (due to the “binding”, the meta class of
> the variable) being different. We could return a nil subclass or add code
> into the method directly. But the problem with that is that nil checks
> are always identity checks…
>
> Could you not in the case you now raise the error just fall back to the
> “define method”, the behaviour we have now?
>
> Marcus
>
>>
>> I will also put together a pr for this in Pharo 7 if you think it’s a decent
>> fix.
>>
>> Tim
>>
>> Sent from my iPhone
>>
>>
>>
>> Sent from my iPhone
>>> On 22 Aug 2018, at 09:51, Marcus Denker <[email protected]> wrote:
>>>
>>> Hi,
>>>
>>> I played with it, nice!
>>>
>>> I guess the case when you really get a DNU on nil (and want to create
>>> method there) does not really happen… extending nil is for special cases.
>>>
>>> Marcus
>>>
>>>
>>>> On 22 Aug 2018, at 13:39, Tim Mackinnon <[email protected]> wrote:
>>>>
>>>> Sorry Marcus - you needed to follow the exercism instructions and right
>>>> click on the exercism package to get an exercism menu to fetch a new
>>>> exercise (e.g. hello-world). The is then using the TonalReader to pull in
>>>> code - and then you get a test class that can reference a class that isn’t
>>>> there yet. (But you need to have the exercism cli installed as per the
>>>> instructions etc).
>>>>
>>>> In retrospect I think it might be simpler to download this 6.1 image that
>>>> already has done that -
>>>> https://www.dropbox.com/s/x2ot9f8arbbvlyb/PharoExercism.zip?dl=0
>>>> It has TwoFerTest that is in that state. If you click on the TestWithName
>>>> orb, you will see "#new was sent to nil” - can you can see how my Create
>>>> button has been fixed per you suggestions to create a class. (The code I
>>>> wrote is in
>>>> ExercismTools:DoesNotUnderstandDebugAction>>createMissingClassIn:)
>>>>
>>>> Tim
>>>>
>>>>
>>>>> On 22 Aug 2018, at 04:44, Marcus Denker <[email protected]> wrote:
>>>>>
>>>>>
>>>>>
>>>>>> On 17 Aug 2018, at 14:20, Tim Mackinnon <[email protected]> wrote:
>>>>>>
>>>>>> The direct link to instructions is here:
>>>>>> https://exercism.io/tracks/pharo/installation (not sure if you have to
>>>>>> be signed up to see it otherwise its in the repo here:
>>>>>> https://github.com/exercism/pharo/blob/master/docs/INSTALLATION.md)
>>>>>
>>>>> Hm… AllExercismTests seems to not be there (just a green test in Welcome)
>>>>>
>>>>> Is this supposed to contain the code below (the
>>>>> createMissingClassActionFor:in:) ?
>>>>>
>>>>> It would be nice to have an image that shows exactly the problem (I do
>>>>> not have that much time sadly to work on it,but I do have some time to
>>>>> check if I have an image that is set up to the point where i can easily
>>>>> recreate the problem)
>>>>>
>>>>> Marcus
>>>>>
>>>>>
>>>>>> Tim
>>>>>>
>>>>>>> On 17 Aug 2018, at 07:17, Marcus Denker <[email protected]> wrote:
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>> On 17 Aug 2018, at 13:00, Tim Mackinnon <[email protected]> wrote:
>>>>>>>>
>>>>>>>>
>>>>>>>> Hi Marcus - I can put an image somewhere if that helps (do you just
>>>>>>>> need the .image and .changes)?
>>>>>>>>
>>>>>>>> Or you can repro from a fresh 6.1 if you follow the exercism Pharo
>>>>>>>> instructions (https://exercism.io/tracks/pharo) to load the first
>>>>>>>> hello world-world example and run the tests. This has my code changes
>>>>>>>> to make create work with a nil class - but maybe we can do better?
>>>>>>> I will do that and have a look!
>>>>>>>
>>>>>>>> Tim
>>>>>>>>
>>>>>>>>
>>>>>>>> Sent from my iPhone
>>>>>>>>
>>>>>>>>> On 17 Aug 2018, at 06:21, Marcus Denker <[email protected]>
>>>>>>>>> wrote:
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>> On 10 Aug 2018, at 23:16, Tim Mackinnon <[email protected]> wrote:
>>>>>>>>>>
>>>>>>>>>> Actually I think I figured that bit out - a bit clumsily - (pointers
>>>>>>>>>> appreciated)
>>>>>>>>>>
>>>>>>>>>> createMissingClassActionFor: aMessage in: aContext
>>>>>>>>>> |errorNode senderContext newClass variableNode |
>>>>>>>>>> senderContext := aContext sender.
>>>>>>>>>> errorNode := senderContext method sourceNodeExecutedForPC:
>>>>>>>>>> senderContext pc.
>>>>>>>>>> variableNode := errorNode receiver receiver.
>>>>>>>>>>
>>>>>>>>>> newClass := OCUndeclaredVariableWarning new node: variableNode;
>>>>>>>>>> defineClass: variableNode name.
>>>>>>>>>> aContext restart.
>>>>>>>>>>
>>>>>>>>>> However that last line is wrong, as it doesn’t restart with my newly
>>>>>>>>>> defined class - I also tried
>>>>>>>>>>
>>>>>>>>>> aContext restartWithNewReceiver: newClass
>>>>>>>>>>
>>>>>>>>>> But again, I get a debugger where my class is still bound to nil. So
>>>>>>>>>> what’s the trick to re-evaluate with the new class I’ve created? Or
>>>>>>>>>> maybe I’m totally on the wrong track (still its very interesting…)
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> what is a bit bad is that you catch the problem “too late” (that is,
>>>>>>>>> the DNU to nil, not the read of nil), so nil is already pushed on the
>>>>>>>>> stack at this point.
>>>>>>>>>
>>>>>>>>> I tried it in the inspector and at least the class binding was
>>>>>>>>> correct after defining the class… do you have an image with the whole
>>>>>>>>> code to try?
>>>>>>>>>
>>>>>>>>> Marcus
>>>
>>>
>>
>>
>
>
