Stef, Thanks for taking time at ESUG to listen and learn more about our namespace proposal. I believe that we have cleared up some of the misconceptions surrounding this complex topic.
James On Jun 27, 2012, at 8:27 AM, Stéphane Ducasse wrote: > > On Jun 27, 2012, at 4:44 PM, James Foster wrote: > >> Stef, >> >> I'm sorry to hear about your burnout and I understand that you are not >> prepared to seriously discuss the issues that others have raised. I hope >> when the issue is raised again (it does seem to come up every year or so!) >> we can correct some of the misunderstandings that exist. > > yes we are discussing regularly that topic and Camille is writing a master > where all the points are discussed and summarized with pros and cons. > Now for 20 we should finish all the open tracks we have. > > Stef > >> >> Best wishes, >> >> James >> >> On Jun 27, 2012, at 12:08 AM, Stéphane Ducasse wrote: >> >>> James >>> >>> sorry but I'm at home stopped for 10 days because of a burnout (linked >>> partly to pharo and the business I want to spawn for the community). >>> We talked endlessly about namespaces and so far we lived happily without. >>> Right now I will not talk about that. Read subsystem the paper of >>> wirfs-brock >>> if you want to see what I would prefer to have. But we need to have a >>> scientific approach to evaluate. >>> And yes I read the implementation two years ago. >>> Finally did you see the list of topics that I mention? >>> - do you want to help in any of them to make pharo better? >>> because we have to get them first and I need all my energy for them. >>> >>> Stef >>> >>> >>> On Jun 27, 2012, at 12:25 AM, James Foster wrote: >>> >>>> On Jun 26, 2012, at 12:51 PM, Stéphane Ducasse wrote: >>>> >>>>> On Jun 26, 2012, at 9:30 PM, James Foster wrote: >>>>> >>>>>> On Jun 26, 2012, at 11:19 AM, Stéphane Ducasse wrote: >>>>>> >>>>>>>>>> What happened to the project from Germán Leiva >>>>>>>>>> http://www.youtube.com/watch?v=n4I7fSVNX2A >>>>>>>>> >>>>>>>>> we do not want class level namespace because this is the mess >>>>>>>> >>>>>>>> As the sponsor for Germán's project, I have some interest in this >>>>>>>> topic. Stéphane has said a couple times that it is wrong but has never >>>>>>>> taken time to explain his objections. >>>>>>> >>>>>>> We do not want to have class name resolution at the granularity of a >>>>>>> class. >>>>>> >>>>>> And are you saying this because you think Germán's implementation does >>>>>> this? >>>>>> >>>>>>> Why because it means that in the same package reading the code >>>>>>> containing a class Foo could be a different one. >>>>> >>>>>>> Why because it means that in the same package, reading the code >>>>>>> containing a class Foo could be a different one. >>>>> ^^^^^ >>>>> >>>>> Class level namespace import means that in a given class, a method >>>>> accessing the variable Foo may end up pointing to another class Foo in a >>>>> class in the same package importing another namespace. >>>> >>>> I still don't understand the definition. What do you mean by "another >>>> class Foo in a class." How can a class be in a class? Is Foo defined in >>>> two packages? Is the method on the class Foo? Should the name be resolved >>>> to the Foo in the package containing the method or to another Foo? Perhaps >>>> it would help if you named the sample classes, packages, and methods. >>>> >>>> Are you saying that if the namespace is allowed to be defined (or refined) >>>> at any level other than the package, then it is lumped into the bucket >>>> called "class level namespace import"? >>>> >>>>>> I don't understand your example. I don't know what you mean by "package >>>>>> reading the code." Are you describing a package that defines classes Foo >>>>>> and Bar, and a method in a class Bar that references the Foo in the same >>>>>> package? Are you providing this example because you think Germán's >>>>>> implementation does not support this use case? >>>>> >>>>> No >>>>> I just say that changing binding of variables at the class level is not a >>>>> good granularity. I do not want to have >>>>> >>>>> Object subclass: #NameOfSubclass >>>>> instanceVariableNames: '' >>>>> classVariableNames: '' >>>>> poolDictionaries: '' >>>>> category: 'Bob' >>>>>>>> environment: >>>> >>>> Is it your impression that Germán's implementation requires this? If so, >>>> on what do you base that understanding? Have you looked at the code? >>>> >>>>>>> I'm saying that since years. >>>>>> >>>>>> I agree you have been saying that Germán's implementation isn't what you >>>>>> want. I just don't understand what you don't like about it. >>>>> >>>>> because this is a class level import. >>>> >>>> I still don't know what you mean by "class level import" or why you think >>>> Germán's implementation fits your definition. >>>> >>>>>> Name resolution of all variables (including Globals, of which Classes >>>>>> are a subset) should be part of a method compile. At the time a method >>>>>> is compiled, an 'environment' should be provided to the compiler that >>>>>> indicates how global name resolution should occur. >>>>> >>>>> Usually this is the class of the method. >>>> >>>> By "Usually" do you mean in pre-namespace Pharo? That is, the class is one >>>> of the factors that the compiler considers in doing name lookup? Is the >>>> "usual" approach good? Would it still be a factor considered by the >>>> compiler in an environment namespace regime? >>>> >>>>>> This is a tools issue and it should be possible to specify the default >>>>>> namespace environment for the method, for a method category, for a >>>>>> class, for a class category, for a package, and for the system as a >>>>>> whole. >>>>> >>>>> no this is a question of language design. >>>> >>>> Do you consider packages to be part of the language? I have always thought >>>> that one of the nice things about Smalltalk is how little of the >>>> development environment is actually part of the language. Being able to >>>> augment things through tools rather than changing the language seems to me >>>> to be a feature, not a bug. >>>> >>>>>> In addition, within a particular method it should be possible to >>>>>> explicitly reference a particular namespace environment, whether through >>>>>> syntax (dot or double colons) >>>>> >>>>> No we do not want to have that. >>>>> We want import to be specified at the border: i.e. during module import. >>>>> Inside a module the world is flat and as a developer I do not want to >>>>> know that this Point is from Core when that one is from MyCore. >>>> >>>> By "I do not want to know" do you mean "I do not want to be required to >>>> specify" or do you mean "I do not want anyone else to be able to find >>>> out"? If I want to know (say, to build tools), would that be okay? If I'm >>>> willing to let you remain ignorant of a global's source would you be >>>> willing to let me be enlightened? >>>> >>>>> If I want both, at the module import level I write >>>>> >>>>> Import: Point from: core as: CorePoint; >>>>> import: Point from: dev as: DevPoint; >>>> >>>> What object implements #'import:from:as:'? >>>> >>>>>> or through message sends (e.g., a Dictionary's #'at:' method). I prefer >>>>>> not to add new syntax and favor GemStone's implementation over that of >>>>>> VisualWorks. >>>>> >>>>> I dislike them both. >>>>> A module should provide a certain level of encapsulation, else naming >>>>> convention is good enough. >>>>> Because else having namespace does not prevent you to have to declare >>>>> that WA is not a namespace somebody else should use. >>>> >>>> You say that you "do not want to" allow code "to explicitly reference a >>>> particular namespace." Do you mean that arbitrary code should not be able >>>> to see a global that is not explicitly imported at package load time and >>>> that code should never be able to explicitly look at and manipulate >>>> namespaces. Really? This seems to me to be very much contrary to the >>>> existing spirit of reflection and introspection in Smalltalk and would >>>> make tools much more limited. I suspect that this is not really what you >>>> mean. >>>> >>>> I believe that a package should be allowed to provide a default >>>> environment, but I don't see the need to make it mandatory or exclusive. I >>>> believe that a class should be allowed to override the default >>>> environment, but I don't think it should be required. >>>> >>>> If a class is allowed (but not required) to override the default (provided >>>> by the package/module, for example), does that make it a "class level >>>> import" (and wrong, in your view)? >>>> >>>> What I understand from your statements so far is that Germán's approach >>>> allows too much flexibility (namespace can be specified not just at the >>>> package level but also at the class level and explicitly in code). You do >>>> not want to allow anyone to experiment with different levels of >>>> granularity. Is that it? >>>> >>>> Thanks for engaging in the discussion. >>>> >>>> James Foster >>>> >>>> >>> >>> >>> >> >> > > >
