Shortest way of creating combinations of array elements

[Schalk Cronjé <ys...@gmail.com>]

I am trying to find the shortest method of creating pairs of values from 
two lists.

    def a = [ 1,2,3,4,5,6 ]
    def b = [ 'a','b','c' ]

    assert [ [ 1,'a'], [2,'a'], ... [5,'c'],[6,'c'] == f(a,b)

The question is what te shortest possible implementation f(a,b) looks like.

I know a.collect { item -> b.collect { [item,it] }  } should work, but 
wondering if there is something better.

-- 
Schalk W. Cronjé
Twitter / Ello / Toeter : @ysb33r

RE: Shortest way of creating combinations of array elements

["Winnebeck, Jason" <Ja...@windstream.com>]

Is this what you want?

http://docs.groovy-lang.org/latest/html/groovy-jdk/java/lang/Iterable.html#combinations%28%29

assert [['a', 'b'],[1, 2, 3]].combinations() == [['a', 1], ['b', 1], ['a', 2], ['b', 2], ['a', 3], ['b', 3]]
assert [[2, 3],[4, 5, 6]].combinations {x,y -> x*y } == [8, 12, 10, 15, 12, 18]


From: Schalk Cronjé [mailto:ysb33r@gmail.com]
Sent: Thursday, November 12, 2015 11:06 AM
To: users@groovy.incubator.apache.org
Subject: Shortest way of creating combinations of array elements

I am trying to find the shortest method of creating pairs of values from two lists.
def a = [ 1,2,3,4,5,6 ]
def b = [ 'a','b','c' ]

assert [ [ 1,'a'], [2,'a'], ... [5,'c'],[6,'c'] == f(a,b)
The question is what te shortest possible implementation f(a,b) looks like.

I know a.collect { item -> b.collect { [item,it] }  } should work, but wondering if there is something better.


--

Schalk W. Cronjé

Twitter / Ello / Toeter : @ysb33r

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