Is it possible to describe modules in terms of packages (as found in Java)?

The features that Java packages have that I can't seem to get in D are:
1) You can have classes that are in the same package, but kept in separate files.
2) You can import many classes using the '*' syntax.

Is this possible in D?

What I understand is that if I have ClassA and ClassB in Module1, and I want to keep the classes in separate files, then I have to use the following module statements:

in ClassA:
module Module1.ClassA;

in ClassB:
module Module1.ClassB;

But now it becomes cumbersome to use the classes because now I have to import them explicitely:

import Module1.ClassA;
import Module1.ClassB;



If I wanted to use:
import Module1;

Then it seems I have to have ClassA and ClassB in the same D file.

Am I missing something?

On Tuesday, 31 December 2013 at 06:01:21 UTC, Afshin wrote:
> Is it possible to describe modules in terms of packages (as found in Java)?
>
> The features that Java packages have that I can't seem to get in D are:
> 1) You can have classes that are in the same package, but kept in separate files.
> 2) You can import many classes using the '*' syntax.
>
> Is this possible in D?
>
> What I understand is that if I have ClassA and ClassB in Module1, and I want to keep the classes in separate files, then I have to use the following module statements:
>
> in ClassA:
> module Module1.ClassA;
>
> in ClassB:
> module Module1.ClassB;
>
> But now it becomes cumbersome to use the classes because now I have to import them explicitely:
>
> import Module1.ClassA;
> import Module1.ClassB;
>
>
>
> If I wanted to use:
> import Module1;
>
> Then it seems I have to have ClassA and ClassB in the same D file.
>
> Am I missing something?


It is possible if you have your file system set up like this.

Module1
    -ClassA.d
    -ClassB.d
    -package.d

//In Module1/ClassA.d
module Module1.ClassA;
class ClassA { ... }

//In Module1/ClassB.d
module Module1.ClassB;
class ClassB { ... }

//In Module1/package.d
module Module1;

public import Module1.ClassA;
public import Module1.ClassB;


//In main.d

module main;

import Module1; //This will import both ClassA and ClassB.

Very important! The name of the file with the public imports must be package.d

>> 2) You can import many classes using the '*' syntax.

You don't use the * syntax. Just stop after the module name.

On 2013-12-31 07:01, Afshin wrote:
> Is it possible to describe modules in terms of packages (as found in Java)?
>
> The features that Java packages have that I can't seem to get in D are:
> 1) You can have classes that are in the same package, but kept in
> separate files.

See below.

> 2) You can import many classes using the '*' syntax.

You cannot do that in D. You can do something similar as described here:

http://forum.dlang.org/thread/garueoxkjjqgqpqqhrmc@forum.dlang.org#post-sdueirvfgsxjtahmapla:40forum.dlang.org

> Is this possible in D?
>
> What I understand is that if I have ClassA and ClassB in Module1, and I
> want to keep the classes in separate files, then I have to use the
> following module statements:
>
> in ClassA:
> module Module1.ClassA;
>
> in ClassB:
> module Module1.ClassB;
>
> But now it becomes cumbersome to use the classes because now I have to
> import them explicitely:
>
> import Module1.ClassA;
> import Module1.ClassB;

Yes, that's how it works in D. That's because in Java there's a one-to-one mapping of classes and files. In D you can have many classes (or other declarations) in the same file. I suggest you use this approach.

> If I wanted to use:
> import Module1;
>
> Then it seems I have to have ClassA and ClassB in the same D file.
>
> Am I missing something?


-- 
/Jacob Carlborg

Afshin:

> in ClassA:
> module Module1.ClassA;
>
> in ClassB:
> module Module1.ClassB;

In D module names usually start with a lowercase letter (usually they are all lowercase, because different file systems manage upper case letters in different ways).

Bye,
bearophile