What does compiling permutation mean in GWT?

When a Web App Project is compiled, 6 permutations are compiled. What are those permut开发者_开发问答ations, and what do they mean?

Google Web Toolkit uses deferred binding; it creates different versions of your application for different browser targets and localizations. Their FAQ response on Deferred Binding goes into more detail, but basically can be summed up in this quote:

For instance, if GWT supports 4 browsers, and you write your application in 3 languages, then GWT will generate a total of 12 different permutations of your application. During bootstrapping at runtime, GWT picks the appropriate permutation to show the user.

It is possible to temporarily remove some browser models and languages to shorten compilation times during development.

You can set the user agent and specify your browser in your *.gwt.xml (x5 compile if you use a specific browser)

For firefox only use: <set-property name="user.agent" value="gecko1_8" />

More info @topic

Skipping permutations is only useful for testing purposes. In example, I'm configuring maven assembly plugin, so skipping them allows me to do configuration tests with assembly MUCH more faster.