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.

score 47 · Accepted Answer · edited Mar 18 '20 at 11:32

47

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)

edited Mar 18 '20 at 11:32

Alexander Druzhynin

103
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answered Jan 07 '14 at 13:39

tim_yates

167,322
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That was right under my nose the entire time... Thank you. (Will accept as answer when the question is old enough) – Lerp Jan 07 '14 at 13:41
Hmm, this doesn't quite do the same as in my OP? `findResults` stops after the first non-null element. – Lerp Jan 07 '14 at 13:47
You've typed `findResult` not `findResults` ;-) – tim_yates Jan 07 '14 at 13:49
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`. – Lerp Jan 07 '14 at 13:53
2

Yeh, it's hard to find some things in the docs... List, Iterable, Collection or Object are all candidate pages some times ;-) – tim_yates Jan 07 '14 at 13:54
Sort of confusing that `findResults` also allows you to transform the collection. Should be named `collectSome` or similar – Mar 06 '16 at 02:17

Collect only if result is not null

1 Answers1