JSON

var json = require('JSON::PP').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"
)
{"ocean":{"water":["fishy","salty"]},"blue":[1,2]}