Add Compact Profile Support

[webfolderio]

Hi,

Is it possible to remove Full JRE dependency. Picocli use java.awt.Point which requires Full JRE.

Thanks

jdeps -P picocli-1.0.0.jar

picocli-1.0.0.jar -> C:\Java\jdk1.8.0_141\jre\lib\rt.jar (Full JRE)
   picocli (picocli-1.0.0.jar)
      -> java.awt                                           Full JRE
      -> java.io                                            compact1
      -> java.lang                                          compact1
      -> java.lang.annotation                               compact1
      -> java.lang.reflect                                  compact1
      -> java.math                                          compact1
      -> java.net                                           compact1
      -> java.nio.charset                                   compact1
      -> java.sql                                           compact2
      -> java.text                                          compact1
      -> java.util                                          compact1
      -> java.util.concurrent                               compact1
      -> java.util.regex                                    compact1

[remkop]

Ok, I can see the value of doing this.

Two things:

• TextTable#putValue is a public method in a public inner class, so the class replacing java.awt.Point also needs to be public. (Also, we may take this opportunity to name the class something clearer than Point... Position, Cell, Address, At come to mind. Other suggestions welcome...)
• this is a breaking API change, so the next version needs to become 2.0.0 since picocli follows semantic versioning

(These are not objections, just noting them)

[remkop]

I also noticed that the type converter for java.sql.Time introduces a dependency on compact2, everything else is compact1.

I wonder if it is worth using reflection to avoid a hard dependency on compact2...

Background: there is an outstanding ticket (#83) to support more built-in types. Some of the types I'm planning to support were introduced in java 7 and java 8. At the same time, I would like picocli to continue be compatible with java 5. To solve this, I plan to use reflection to implement type converters for java.time.* classes, java.nio.file.Path, etc.

So if we will be using reflection anyway, why not use reflection for anything other than compact1?
Thoughts?

[webfolderio]

I wonder if it is worth using reflection to avoid a hard dependency on compact2...

Its OK, there is no big difference between compact 1 and compact2 profile.

Here is JRE 8 size for windows platform:

• compact1 15MB
• compact2 20MB
• cmpact3 23MB
• j2re-full 54MB

So if we will be using reflection anyway, why not use reflection for anything other than compact1?

I think there is no reason to use reflection. CommandLine.java and common types (Date, Time, BigDecimal...) should depend on compact profile. If a type requires Full JRE you might place them as an extension project.