CODEWITHSUNDEEP
groovyclosuresdynamic-programming
Roy Truelove
Roy Truelove

Reputation: 22456

Groovy - expanding list into closure arguments

Is it possible to have a list and use it as an argument for a closure signature that instead several variables? The reason is that I have to call a closure from java code, and the java code won't know what variables the groovy closure needs.

This is better served with an example.

Say I have a 'closure repository', where each closure might have different signatures. EG:

closures = [
    closureA: { int a, String b ->
        a.times {
            System.err.println(b);
        }
    },
    closureB: { int a, int b, String c ->
        (a+b).times {
            System.err.println(c);
        }
    }
]

Then I've got a method that I'm exposing to my java code to call these closures:

def tryClosureExpansion(String whichClosure, Object ... args) {
    def c = closures[whichClosure]
    c.call(args)     // DOESNT COMPILE !
}

And it Java I'd call this method like this:

// these calls will happen from Java, not from Groovy
tryClosureExpansion("closureA", 1, "Hello");
tryClosureExpansion("closureB", 1, 5, "Hello more");

See above on the line that doesn't compile. I feel like groovy is 'groovy' enough to handle something like this. Any alternative that might fly?

Upvotes: 8

Views: 3154

Answers (1)

tim_yates
tim_yates

Reputation: 171084

Does:

c.call( *args )

Work? Not at a computer atm to test it

Upvotes: 11

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