Proposal for a simplified syntax for invoking @FunctionalInterface methods
maurizio.cimadamore at oracle.com
Thu Mar 23 13:54:53 UTC 2017
This is a question for lambda-dev.
Something like this was present in the very first draft of the lambda
language support  - syntax aside, the main issue with this avenue, is
that Java has separate namespaces for methods and fields. That is, you
are able to declare a field AND a method whose type is 'doubleString'.
So, if you start treating fields in a more method-y way, the namespace
issue might pop up, and ambiguities might ensue.
 - http://cr.openjdk.java.net/~mr/lambda/straw-man/
On 02/03/17 15:10, Timothy Fagan wrote:
> I'm not sure if this is the appropriate forum, or if this idea has been
> proposed elsewhere, but I'd like to suggest a simplified syntax for
> invoking @FunctionalInterface methods.
> The idea is that if:
> * foo is a object reference (field, local variable or parameter) whose
> type is a @FunctionalInterface
> * there is a statement or expression where foo is used as if it were a
> method name
> * the formal parameters of the statement or expression match the formal
> parameters of the abstract method on the @FunctionalInterface
> * the formal parameters of the statement or expression do NOT match the
> formal parameters of any other method in scope named foo
> * the statement or expression is compiled as an invocation of the
> @FunctionalInterface abstract method on foo's type.
> Function<String, String> doubleString = s -> s + s;
> // prints "hellohello"
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