#!/usr/bin/ruby
#
## Tests for Array.cartesian()
#
assert_eq(
    gather {
        [^3, ^3, ^3].cartesian { |a,b,c|
            take([a,b,c])
            if (b==2 && c==1) {
                break
            }
        }
    }, [[0, 0, 0],[0, 0, 1],[0, 0, 2],[0, 1, 0],[0, 1, 1],[0, 1, 2],[0, 2, 0],[0, 2, 1]]
)
var arr = [[:a,:b], [:c,:d], [:e,:f,:g]]
assert_eq(
    gather {
        arr.cartesian { |*a| take(a) }
    },
    [["a", "c", "e"],
     ["a", "c", "f"],
     ["a", "c", "g"],
     ["a", "d", "e"],
     ["a", "d", "f"],
     ["a", "d", "g"],
     ["b", "c", "e"],
     ["b", "c", "f"],
     ["b", "c", "g"],
     ["b", "d", "e"],
     ["b", "d", "f"],
     ["b", "d", "g"]]
)
assert_eq(arr, [[:a,:b], [:c,:d], [:e,:f,:g]])
assert_eq(cartesian([[1, 2, 3], [30], [500, 100]]), [[1, 30, 500], [1, 30, 100], [2, 30, 500], [2, 30, 100], [3, 30, 500], [3, 30, 100]])
assert_eq(cartesian([[1, 2, 3], [], [500, 100]]), [])
assert_eq(cartesian([[1,2], [3,4]]), [[1, 3], [1, 4], [2, 3], [2, 4]])
assert_eq(cartesian([[3,4], [1,2]]), [[3, 1], [3, 2], [4, 1], [4, 2]])
say "** Test passed!"