random idea

Question

random idea <https twitter com warianoguerra status 1040525691048128512>

Vladimir Gordeev · Answer

If so what s the difference between modules and objects then If it s basically the same do modules have to be first class

Mariano Guerra · Answer

there s not much of a difference but you have to treat them differently You can t access all the implicit behaviour of modules with objects the closest I saw was the with statement in javascript and object capability model but why not just make modules just objects and unify the resolution logic in scopes to allow modifying introspecting the scope chain

Mariano Guerra · Answer

in many programming languages you can t pass modules as values Imagine if the top of your module instead of being a sequence of imperative imports and renames was treated as an interface your module expects to be instantiated and then you can override the default references provided by the global module system mocking and sandboxing would be builtin

Vladimir Gordeev · Answer

Well such change will make whole thing more flexible Make mocking in tests much easier Not sure would it make things easier though

Mariano Guerra · Answer

mocking sandboxing dependency injection and registries wouldn t be needed that s a big simplification

Mariano Guerra · Answer

also module object distinction would disappear and the dual resolution between scopes and global module system would disappear too

Mariano Guerra · Answer

I would like to have to think about less things slightly smiling face

Vladimir Gordeev · Answer

But this big singleton thing is not going away right

Mariano Guerra · Answer

no it s just another instance that s there by default you can remove it explicitly or introspect it

Mariano Guerra · Answer

```Newspeak is a new programming language in the tradition of Self and Smalltalk Newspeak is highly dynamic and reflective but designed to support modularity and security It supports both object oriented and functional programming Like Self Newspeak is message based all names are dynamically bound However like Smalltalk Newspeak uses classes rather than prototypes As in Beta classes may nest Because class names are late bound all classes are virtual every class can act as a mixin and class hierarchy inheritance falls out automatically Top level classes are essentially self contained parametric namespaces and serve to define component style modules which naturally define sandboxes in an object capability style ```

Mariano Guerra · Answer

don t know a lot about the details but Newspeak sounds like it s going in that direction

Vladimir Gordeev · Answer

Seems like so Don t know what to say I still feel pessimistic about it Things are really complicated when modules do have state

Vladimir Gordeev · Answer

There are two problems dependencies of code and dependencies of state If modules are just pack of functions without internal state I guess it will make it easier to tackle with second problem

Mariano Guerra · Answer

I like immutable languages wink

Mariano Guerra · Answer

modules as stateless interfaces with associated implementations

Mariano Guerra · Answer

you can layer partial implementations like scopes to override different parts

Vladimir Gordeev · Answer

yeah good idea

Mariano Guerra · Answer

Mariano Guerra · Answer

check also at minute 9

Vladimir Gordeev · Answer

Yeah he also talks about it I don t have the vision to understand is it awesome or not

shalabh · Answer

I feel this is related to the idea of early late binding wrt time T In Python you can overwrite a module at runtime by doing something like ``` import moduleA moduleA moduleB = myModuleB ``` This will affect all references to `ModuleB foo` from within moduleA but not all cases only explicit global lookups of ModuleB You can also pass modules around as objects Are you thinking about something similar

Mariano Guerra · Answer

that s one part it s kind of first class because it behaves like an object but changes to alter resolution of some value inside the module are global and as you mentioned there s no way to change the values for other modules who hold a reference to moduleB not through moduleA What can be achieved in python sounds like monkey patching in ruby and we know what that s like slightly smiling face

shalabh · Answer

Yes its similar You can also overwrite the global `sys modules moduleB = newModuleB` and it will change for all modules that reference moduleB because the runtime lookup goes through that dict Monkey patching is powerful and make mocking etc very easy but the issue is doing it in a controlled transactional way

shalabh · Answer

Sorry I misspoke changing sys modules will not change the already bound imports

shalabh · Answer

In new versions of Python you can partially hack this by implementing getattr at the top level of your module <https www python org dev peps pep 0562 > In general I think first class modules and good support for routing binding modules at runtime seem like a good idea