Fun with reactive functions...
=MAP('hello', name => 'hello ' + name + '!!!')
=MAP("bla", (a, b) => a + ', ' + b)
=MAP('concat', (...list) => list.join('; ')) 50
=MAP('give', n => Array(n).fill(0).map((i, j) => j)) =concat.value( ...give.value(D3))