selectPairs -- select a part of a hash table by pairs

i1 : x = hashTable{(1, 2), (2, 4), (3, 6), (4, 8), (5, 10)}

o1 = HashTable{1 => 2 }
               2 => 4
               3 => 6
               4 => 8
               5 => 10

o1 : HashTable

i2 : selectPairs(x, (k,v) -> odd(k + v))

o2 = HashTable{1 => 2 }
               3 => 6
               5 => 10

o2 : HashTable

i3 : selectPairs(2, x, (k, v) -> odd(k + v))

o3 = HashTable{1 => 2}
               3 => 6

o3 : HashTable

i4 : selectPairs(toList(1..10), (i, x) -> even x)

o4 = {(1, 2), (3, 4), (5, 6), (7, 8), (9, 10)}

o4 : List

i5 : selectPairs(3, toList(1..10), (i, x) -> even x)

o5 = {(1, 2), (3, 4), (5, 6)}

o5 : List