hg: penrose/penrose: 1. Update Penrose demos to support JSON format module info.

[Shi Jun Zhang]

On 7/5/2012 1:45 AM, Paul Sandoz wrote:
> Hi,
>
> On Jul 4, 2012, at 4:42 PM, David Bosschaert wrote:
>
>> Hi Shi Jun,
>>
>> On 4 July 2012 12:04, David Bosschaert<david.bosschaert at gmail.com>  wrote:
>>> On 4 July 2012 07:36, Shi Jun Zhang<zhangshj at linux.vnet.ibm.com>  wrote:
>>>> 2. Error message is not clear enough. I typed "jdk.desktip" by mistake in
>>>> requires section in modulebrowser, and then I got an error said
>>>> "modulebrowser cannot be solved" when installing the module into module
>>>> library. It should tell "jdk.desktip cannot be solved" instead.
>>> Thanks - I'll look into that.
>> Actually this is more of an issue for the Jigsaw resolver. It should
>> report better why a module cannot be resolved, so let's say
>> com.greetings.json has a dependency that isn't found, it simply
>> reports this:
>>
>> org.openjdk.jigsaw.ConfigurationException: com.greetings.json@=0.1:
>> Cannot resolve
>> 	at org.openjdk.jigsaw.Resolver.fail(Resolver.java:91)
>> 	at org.openjdk.jigsaw.Resolver.run(Resolver.java:460)
>> 	at org.openjdk.jigsaw.Configurator.configure(Configurator.java:144)
>> 	at org.openjdk.jigsaw.Configurator.configure(Configurator.java:204)
>> 	at org.openjdk.jigsaw.SimpleLibrary.configureWhileModuleDirectoryLocked(SimpleLibrary.java:1720)
>> 	at org.openjdk.jigsaw.SimpleLibrary.installFromManifests(SimpleLibrary.java:1154)
>> 	at org.openjdk.jigsaw.cli.Librarian$Install.go(Librarian.java:207)
>>
>> If the resolver would give a better error message that would resolve
>> your issue.
> Yes, another TODO :-) Very important to make such errors as a clear and meaningful as possible.
>
> In the interim if you set the JIGSAW_TRACE environment variable e.g.:
>
>   export JIGSAW_TRACE=1000
>
> you will see tracing output from the resolver.

Thanks. That's helpful.

>
>
>> The resolver is independent from the JSON module metadata,
>> because the module metadata is internally represented in the same way,
>> regardless of whether it was read from a module-info.json or a
>> module-info.class file.
>>
>> With the module-info.java you get this warning earlier, during the
>> javac process as it converts the .java file into a .class file. The
>> .json file does not need to be compiled, but it would be good if the
>> javac compiler could validate it in the future. BTW the error message
>> from javac doesn't tell you why the resolution failed either right
>> now...
>>
> The resolver will also be used by javac, so i would expect an error when compiling such a module.
>
> Was the JSON module declaration modified after compilation?
>
> Paul.
>
The module-info.json will not be compiled. We didn't do any changes in 
javac.

-- 
Regards,

Shi Jun Zhang