[isabelle-dev] JDK 8 release

[Makarius]

According to the plan (which was revised many times before), Oracle
has released official JDK 8 two days ago.  See also 
http://www.oracle.com/technetwork/java/javase/downloads/index.html

It is interesting to see that Java 8 now takes pride in functional 
programming basics, with several decades of delay.  When I was a young 
student, there was this odd social phenomenon that the label 
"object-oriented" had to be attached to everything that considered itself 
important and "up-to-date", but times have changed a lot.

For us, slight reforms of the Java source language are not of primary 
importance.  What counts is the JVM as basis for the higher-order 
object-oriented functional parallel-and-asynchronous programming of Scala 
-- Odersky had the 10th anniversary recently.


I did not have time yet to try out JDK 8 systematically, but it still 
looks fine after 5min of testing.  People who want to do it themselves can 
add something like this to $ISABELLE_HOME_USER/etc/settings:

   ISABELLE_JDK_HOME="/Library/Java/JavaVirtualMachines/jdk1.8.0.jdk/Contents/Home"

where the directory in question is the regular JAVA_HOME of a normal 
installation of JDK from Oracle.

It is important to keep such manual changes of settings in mind, when 
official Isabelle components of newer versions of JDK 8 become available 
eventually (maybe after 1 or 2 more releases by Oracle).


For the summer release of Isabelle, we should be routinely on JDK 8 on all 
platforms as usual.  (Hopefully with less problems due to Linux window 
manager fragmentation, although this affects only a minority of users.)


 	Makarius