P4
ADDITIONAL SYSTEM INFORMATION :
C:\Users\hwaite>ver
Microsoft Windows [Version 10.0.17763.914]
C:\Users\hwaite>C:\jdk-13.0.1\bin\java -version
openjdk version "13.0.1" 2019-10-15
OpenJDK Runtime Environment (build 13.0.1+9)
OpenJDK 64-Bit Server VM (build 13.0.1+9, mixed mode, sharing)
A DESCRIPTION OF THE PROBLEM :
Callback is a redundant interface; Ideally we'd remove. Since that might break too much existing code, next best thing is to make it a sub-interface of Function. At least this allows users to leverage Callbacks more broadly. It will also allow for more graceful deprecation in the future. This seems to be the approach taken by Guava team with com.google.common.base.Function (see Guava v20 vs Guava v21).
C:\Users\hwaite>ver
Microsoft Windows [Version 10.0.17763.914]
C:\Users\hwaite>C:\jdk-13.0.1\bin\java -version
openjdk version "13.0.1" 2019-10-15
OpenJDK Runtime Environment (build 13.0.1+9)
OpenJDK 64-Bit Server VM (build 13.0.1+9, mixed mode, sharing)
A DESCRIPTION OF THE PROBLEM :
Callback is a redundant interface; Ideally we'd remove. Since that might break too much existing code, next best thing is to make it a sub-interface of Function. At least this allows users to leverage Callbacks more broadly. It will also allow for more graceful deprecation in the future. This seems to be the approach taken by Guava team with com.google.common.base.Function (see Guava v20 vs Guava v21).