[Gambas-user] Proposal for namespace support

[Benoît Minisini]

Le 12/05/2021 à 01:06, Christof Thalhofer a écrit :
> Hi Benoît,
> 
> Am 11.05.21 um 23:30 schrieb Benoît Minisini:
> 
>> Here is the result of my thoughts about namespace support.
> 
> Thank you!
> 
>> I tried to find the simpler and less disturbing solution for the
>> interpreter code.
>>
>> 1) A new syntax for exporting classes.
>>
>> ' Class MyClass
>> Export As NameSpace:PublicName
>>
>> will export the class MyClass in the global table as "NameSpace:PublicName"
> 
> Looks good for me if we see the CamelCase in the IDE. Here I think of
> things like
> 
> ComCompanyDb:Orm
> ComCompanyCrypt:Hash
> 
>> The MyClass name is still available inside the code of the current project.
> 
> Is the class also available inside the project under its Namespace
> entry? This would make it easier to test it with gb.test.

Only if it is exported.

Exporting makes the string "NameSpace:ClassName" points at the class 
MyClass inside the global symbol table.

> 
>> Note that the old 'Export' keyword alone would be an equivalent of
>> 'Export As MyClass'
> 
> If we could do as a shortcut:
> 
> ' Class MyClass
> Export As NameSpace:
> 
> and this were extended to 'NameSpace:MyClass', that would be fine. Here
> I think about typos where one would name the class file 'MyClass', then
> writes 'Export As NameSpace:MzCass'.

I don't really like the syntax, but I get the point.

> 
> Another Point: Can we make an entry in the '.project' file
> 'namespace=MyNameSpace' and if it is filled every class  in the project
> is automatically exported with 'MyNameSpace'? Except classes that the
> author explicitly exported with another namespace.
> 
> This would also prevent us from typos. Is that complicated?
> 

Not a good idea to export all classes of a project.

But we can imagine that 'Export' alone will export to the default 
namespace of the project, and that the "default default" namespace is 
the global symbol table.

>> 2) A new syntax for class names.
>>
>> Dim A As NameSpace:PublicName
>>
>> will automatically get the class named 'NameSpace:PublicName class' in
>> the global table by the export made in 1)
> 
> With static classes this happens analogously? So that we can write:
> 
> 'NameSpace:MyModule.MyMethod()'

I didn't think about class names used for calling static methods.

Yes, logically we should be able to do that. It's just problematic for 
the compiler parser... must think about that.

> 
> If this becomes too long, other languages provide aliases. For example PHP:
> 
> https://www.php.net/manual/en/language.namespaces.importing.php
> 
> has the syntax
> 
> 'use MyReallyVeryLongNamespace as MyLong;'

This is a common feature I don't really want. Because then you can 
mismatch the reader of the code, which cannot be sure which namespace we 
refer at first sight.

Regards,

-- 
Benoît Minisini