Module: Diggable

Defined in:
lib/diggable.rb,
lib/diggable/version.rb

Overview

Include in a class to give it the #dig method. It’s implemented so that it calls public methods.

Example:

class MyClass
  include Diggable

  attr_accessor :foo, :bar

  def initialize(foo:, bar:)
    @foo = foo
    @bar = bar
  end
end

obj = MyClass.new foo: [1, 2 ,3], bar: { some: { inner: :value } }
obj.dig(:foo, 0) #=> 1
obj.dig(:bar, :some, :inner) #=> :value

hash = { my_obj: MyClass.new(foo: 1, bar: ['hi mom', 'hi dad']) }
hash.dig(:my_obj, :foo) #=> 1
hash.dig(:my_obj, :bar, 1) #=> 'hi dad'

Constant Summary collapse

VERSION =

Returns:

  • (String) 
'0.1.0'

Instance Method Summary collapse

Instance Method Details

#dig(*args) ⇒ Object

Extracts the nested value specified by the sequence of key objects by calling dig at each step, returning nil if any intermediate step is nil.

This implementation of dig uses public_send under the hood.

Parameters:

  • args (Array<Symbol>, Array<String>)

Returns:

  • (Object)

Raises:

  • (TypeError) —

    value has no #dig method



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# File 'lib/diggable.rb', line 38

def dig(*args)
  return unless args.size.positive?

  return unless respond_to?(key = args.shift)

  value = public_send(key)
  return if value.nil?
  return value if args.empty?
  raise ::TypeError, "#{value.class} does not have #dig method" unless value.respond_to?(:dig)

  value.dig(*args)
rescue ::ArgumentError
  nil
end