Java Method References and higher order functions

[bdw429s]

And finally this enhancement as well has come from this discussion:

New Feature: Functional binding to member methods

This is a follow-on from yesterday’s post that showed how BoxLang now allows you to perform functional static binding to BIFs (built in functions) like so: [ "luis", "brad", "jon" ].map( ::uCase ) // [ "BRAD","LUIS","JON" ] Another type of method reference you may want to bind to is a member method on an object. Member methods could be order.submit() // method on a class companyName.uCase() // BoxLang string member method companyName.getBytes() // Java String member method So, historical…

@seancorfield This one is based on what we discussed as

SomeClass::.instanceMethod – treating such unbound Java instance method reference

We analyzed the syntax as well as how some other dynamic languages and even JS frameworks handle this sort of thing. In the end

• Since “member methods” in CF/BL are more of a loose concept, and can be member methods on a java class, or “magic” member methods from CF/BL types like numeric or array, the class name didn’t really work in all scenarios, so we simplified the syntax to simply .methodName
• instead of ::. we went with just a period in front of the construct to look like a headless method call which is a bit more readable.
• I’m not sure about Clojure, but java’s String::concat method binding doesn’t allow args to be specified. We are also allowing .methodName( arg ) to include arg(s) along with the member method binding.

pendingOrders.each( .submit )

or

[ "brad", "luis", "jon" ].map( .left( 1 ) ); // [ "b", "l", "j" ]

There are more examples in the linked thread, and even more examples on the ticket.