This feature has been a long time coming. It was suggested as far back as 2001, and was closed at that time with the following comment by Gilad Bracha:
Humans benefit from the redundancy of the type declaration in two ways. First, the redundant type serves as valuable documentation – readers do not have to search for the declaration of getMap() to find out what type it returns. Second, the redundancy allows the programmer to declare the intended type, and thereby benefit from a cross-check performed by the compiler.
Interesting, I kinda agree about the need for redundancy at times (which is not forbidden by ML typing). But it rejected a very good idea for a decade.. A bit like lambda expressions. Damn Java
——— start quote ———
This feature has been a long time coming. It was suggested as far back as 2001, and was closed at that time with the following comment by Gilad Bracha:
Humans benefit from the redundancy of the type declaration in two ways. First, the redundant type serves as valuable documentation – readers do not have to search for the declaration of getMap() to find out what type it returns. Second, the redundancy allows the programmer to declare the intended type, and thereby benefit from a cross-check performed by the compiler.
——— end quote ———
Link to original RFE and quote source: https://bugs.java.com/bugdatabase/view_bug.do?bug_id=4459053