This is a bit related to the discussion about version().

In the Lambda the Ultimate blog-forum they are discussing about better support in languages for API Evolution:

http://lambda-the-ultimate.org/node/2950

In the discussion someone has said that it may be useful a syntax to specify what version of a module/package must be imported. (And now and then I have seen people in Python mailing lists ask for something similar, they have several versions of the same module/package and they want other modules to import only the right version).

A first possible raw idea:

This looks for a module foo strictly version 1.3:
import foo(1.3, 1.4) : bar;

This looks for a module foo version 1.3 or 1.4 only:
import foo(1.3, 1.4) : bar;

This looks for a module foo version 1.3 or successive:
import foo(1.3, +) : bar;

The compiler is of course supposed to look for modules by itself, as bud does, and it rises a compilation error if an acceptable version isn't available.

That idea may also need a way to define the version of the current module, a raw idea:

module foo(1.4);

A small problem is that versions of such module/package will have the same name, so you can't put them in the same directory...

Bye,
bearophile

bearophile wrote:
> This is a bit related to the discussion about version().
> 
> In the Lambda the Ultimate blog-forum they are discussing about better support in languages for API Evolution:
> 
> http://lambda-the-ultimate.org/node/2950
> 
> In the discussion someone has said that it may be useful a syntax to specify what version of a module/package must be imported. (And now and then I have seen people in Python mailing lists ask for something similar, they have several versions of the same module/package and they want other modules to import only the right version).
> 
> [snip]
> 
> Bye,
> bearophile

Couldn't you just compile with a specific version?  I don't see a reason for the language to support this when D currently doesn't even have the concept of libraries.

If anything, this should be a candidate feature for DSSS.  Maybe you could do it like so:

version( build )
{
    // Obviously, you'd only use ONE of these...
    pragma( library_version, derelict.gl, "1.3.*" );
    pragma( library_version, derelict.gl, "1.3.*", "1.4.*" );
    pragma( library_version, derelict.gl, "1.3+" );
}

import derelict.gl;

DSSS could then download and install the appropriate version if it isn't already present.

  -- Daniel

Daniel Keep wrote:
> bearophile wrote:
>> This is a bit related to the discussion about version().
>>
>> In the Lambda the Ultimate blog-forum they are discussing about better support in languages for API Evolution:
>>
>> http://lambda-the-ultimate.org/node/2950
>>
>> In the discussion someone has said that it may be useful a syntax to specify what version of a module/package must be imported. (And now and then I have seen people in Python mailing lists ask for something similar, they have several versions of the same module/package and they want other modules to import only the right version).
>>
>> [snip]
>>
>> Bye,
>> bearophile
> 
> Couldn't you just compile with a specific version?  I don't see a reason for the language to support this when D currently doesn't even have the concept of libraries.
> 
> If anything, this should be a candidate feature for DSSS.  Maybe you could do it like so:
> 
> version( build )
> {
>     // Obviously, you'd only use ONE of these...
>     pragma( library_version, derelict.gl, "1.3.*" );
>     pragma( library_version, derelict.gl, "1.3.*", "1.4.*" );
>     pragma( library_version, derelict.gl, "1.3+" );
> }
> 
> import derelict.gl;
> 
> DSSS could then download and install the appropriate version if it isn't already present.
> 
>   -- Daniel

This kind of thing would be awesome, whether it be by language builtins or by DSSS.  It's also the kind of thing I might just get frustrated and write at some point.  DSSS needs to act a bit more like portage ;)