json to ruby literal

literal.rb

require 'json'
require 'unparser'

include Unparser::NodeHelpers

def mk_hash(hash)
  s(:hash, *mk_pairs(hash))
end

def mk_pairs(hash)
  hash.map do |key, value|
    s(:pair,
      s(:sym, key.to_sym),
      mk_value(value)
    )
  end
end

def mk_value(value)
  case value
  when String
    s(:str, value)
  when Array
    mk_array(value)
  when Hash
    mk_hash(value)
  when Integer
    s(:int, value)
  when NilClass
    s(:nil)
  when TrueClass
    s(:true)
  when FalseClass
    s(:true)
  else
    fail "Not a supported literal: #{value.class}"
  end
end

def mk_array(values)
  s(:array, *values.map(&method(:mk_value)))
end

puts Unparser.unparse(mk_value(JSON.load_file('response.json')))

Note it creates symbol keys, was required for my case.

To make it more generic call:

    s(:pair,
      mk_value(key),
      mk_value(value)

instead of:

    s(:pair,
      s(:sym, key.to_sym),
      mk_value(value)