Splitting list into a list of possible tuples

Question

I need to split a list into a list of all possible tuples, but I\'m unsure of how to do so.

For example:

pairs [\"cat\",\"dog\",\"mouse\"]
         


        

Answer 1

You can use a list comprehension:

allpairs :: Eq a => [a] -> [(a,a)]
allpairs xs = [ (x1,x2) | x1 <- xs, x2 <- xs, x1 /= x2 ]