module-info platform dependencies

[Jonathan Gibbons]

On May 15, 2009, at 9:14 AM, Mark Reinhold wrote:

>> Date: Fri, 15 May 2009 08:52:49 -0700
>> From: jonathan.gibbons at sun.com
>
>> So can you give me a method that maps a target number into an
>> equivalent version query, or do I hard-code ("jdk@>=" + targetValue)
>> into the compiler?
>
> The former, of course.  How about this:
>
>    public class org.openjdk.jigsaw.Platform {
>        public static boolean isPlatformModuleName(String mn);
>        public static ModuleIdQuery defaultPlatformModule(int target);
>    }


Either that (int target) or a nice friendly type-safe enum.


>
>
>> "jdk" seems like the wrong name to use eventually.  If you're writing
>> it into the module-class file, we don't want to constrain apps to run
>> on a large platform.  But, it'll do for now.
>
> Actually, "jdk" is the wrong name because it refers to an  
> implementation
> of the Java platform rather than the platform itself.  The default  
> should
> really be "java@>=7", but I haven't implemented the "provides" feature
> yet, so we can't do that yet.
>
> I do think that the default should be upon the whole platform.  That's
> effectively what it is today.  If you want something smaller then  
> you can
> specify it, or maybe use a tool which can analyze your class  
> dependences,
> identify the smallest suitable platform module, and insert that into  
> your
> module-info source file.

The default today is that if I compile something like Hello World, it  
will run
on any version of the platform, even the smallest. (Well, perhaps not  
JavaCard.)

>
>
> - Mark