module vs import

Tomas Lindquist Olsen tomas at
Tue Jun 10 03:17:10 PDT 2008

Tomasz Sowiñski wrote:
> Robert Fraser Wrote:
>> The "module" keyword is used to assign a name to your module (which 
>> incidentally must coincide with its filename & folder structure) while 
>> "import" gives you access to the module with the given name.
> By the way, why do you have to repeat the filename in the file itself? I'm sure there must be some reason, but I can't see it now.
> Tomek

First, the module identifier *must* not coincide with the file path.

One case where this is useful, and not mentioned in the other replies (I think), is when a 
module can have multiple implementations. The module that imports find could be a .di file, for 
example foobar.di, while the actual implementation .d files could have other file names, for 
example foobar_win32.d, foobar_linux.d etc, here the module identifier is necessary to mangle 
symbols correctly.

If you're using Makefiles or simple scripts to build your software this is an entirely feasible 

Of course D has the 'version' keyword for this, but sometimes the code can be very big and 
seperate files might be more maintainable. I personally prefer switching my editor to another 
file than scrolling a hundreds of lines to look at the other implementation.


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