JSON

var json = require('JSON').new
var data = json.decode('{"blue": [1, 2], "ocean": "water"}')
say data
data{:ocean} = Hash(water => %w[fishy salty])
say json.encode(data)

Output:

Hash(
    'blue' => [1, 2],
    'ocean' => 'water'
    )
{"blue":[1,2],"ocean":{"water":["fishy","salty"]}}