http://www.perlmonks.org?node_id=505047


in reply to cross combinations

I beleive Perl6's solution could be as concise and lazy as Haskell's one:
[(x,y)|x<-[1,2],y<-[3,4]]
... reesults in (when running in GHCi)
[(1,3),(1,4),(2,3),(2,4)]