add functions to obtain Java classes to java.base

As part of my continuing campaign to alleviate the need to use ceylon.interop.java for most programming tasks, I propose adding the following functions to java.base (in java.lang, I guess):

• Class<out T> classForInstance<T>(T instance)
• Class<out T> classForModel<T>(ClassOrInterface<T> model)
• Class<out Anything> classForDeclaration(ClassOrInterfaceDeclaration declaration)
• classForAnnotation() ???
• ObjectArray<StackTraceElement> stackTrace(Throwable throwable)

This would alleviate the need to use ceylon.interop.java for anything except collection adaptors.

[jvasileff]

There would be Ceylon source code for a Ceylon module called java.lang which would include declarations for everything added to java.lang. All declarations would be native. Ceylon-docs for this module would be published to Herd.

Users wouldn’t actually import this module. From their perspective, these declarations would be made available by importing java.base, just as the java.lang declarations in Oracle’s Java-docs are made available by importing java.base.

[gavinking]

Why can’t we use top-levels? Needing Type.

Well, I could have, but as was suggested here above, it’s weird that there would be toplevel functions in java.lang when Java doesn’t have toplevel functions.