Collect only if result is not null

Question

I have a collection and I'm wanting to find certain elements and transform them. I can do this in two closures but I was wondering if it is possible with only one?

def c = [1, 2, 3, 4]

def result = c.findAll {
    it % 2 == 0
}

result = result.collect {
   it /= 2
}

My true use case is with Gradle, I want to find a specific bunch of files and transform them to their fully-qualified package name.

Asseveration

Answer 1

You can use findResults:

def c = [1, 2, 3, 4]
c.findResults { i ->
        i % 2 == 0 ?    // if this is true
            i / 2 :    // return this
            null        // otherwise skip this one
    }

Also, you will get [] in case none of the elements satisfies the criteria (closure)

Interbedded

That was right under my nose the entire time... Thank you. (Will accept as answer when the question is old enough) – Asseveration

Hmm, this doesn't quite do the same as in my OP? findResults stops after the first non-null element. – Asseveration

You've typed findResult not findResults ;-) – Interbedded

Ahh this explains why I couldn't find it, I was looking at the Collection docs, not the Iterable docs and the Collection docs only has findResult. – Asseveration

Yeh, it's hard to find some things in the docs... List, Iterable, Collection or Object are all candidate pages some times ;-) – Interbedded

Sort of confusing that findResults also allows you to transform the collection. Should be named collectSome or similar – Teethe