module DeepHashStruct

Mixin module for converter.

Constants

VERSION

Public Instance Methods

deep_struct(input) click to toggle source

Converts a Hash to a Struct. If the Hash has nested Hash objects, they are converted to Struct as well.

output = deep_struct({x: 1, y: {z: 2}})
output.x #=> 1
output.y.z #=> 2

@param [Hash] input @return [Struct]

# File lib/deep_hash_struct.rb, line 13
def deep_struct(input)
  output = input.clone
  levels = expand_levels(output)
  collapse_levels(levels)
  klass = Struct.new(*output.keys, keyword_init: true)
  klass.new(output)
end

Private Instance Methods

collapse_levels(levels) click to toggle source

# File lib/deep_hash_struct.rb, line 46
def collapse_levels(levels)
  levels.reverse_each do |k, context|
    if context[k].is_a?(Hash)
      klass = Struct.new(*context[k].keys, keyword_init: true)
      context[k] = klass.new(context[k])
    end
  end
end

deep_struct_enumerable(enumerable) click to toggle source

@param [Enumerable] enumerable

# File lib/deep_hash_struct.rb, line 41
def deep_struct_enumerable(enumerable)
  enumerable.map { |v| v.is_a?(Hash) ? deep_struct(v) : v }
end

expand_levels(output) click to toggle source

# File lib/deep_hash_struct.rb, line 21
def expand_levels(output)
  levels = output.keys.map { |key| [key, output] }
  levels.each do |key, context|
    if context[key].is_a?(Hash)
      # overwrite the shared reference with input by a new reference
      context[key] = context[key].clone
      subset = context[key]
      subset.each do |subkey, subvalue|
        levels.push([subkey, subset]) if subvalue.is_a?(Hash)
        subset[subkey] = deep_struct_enumerable(subset[subkey]) if subvalue.is_a?(Array)
      end
    elsif context[key].is_a?(Array)
      context[key] = deep_struct_enumerable(context[key])
    end
  end
  levels
end