Rubyには差分を求めるライブラリが存在する
require 'diff/lcs'
Diff::LCS.diff(A, B): 配列の要素に差があれば差分をとる
Diff::LCS.diff([2, 3, 4, 'b'], [1, 2, 3, 'a', 'b'])
# => [[["+", 0, 1]], [["-", 2, 4], ["+", 3, "a"]]]
Diff::LCS.sdiff(A, B): 配列の要素１つごとに差分があるかを返す
Diff::LCS.sdiff([2, 3, 4, 'b'], [1, 2, 3, 'a', 'b'])
# => [["+", [0, nil], [0, 1]], ["=", [0, 2], [1, 2]], ["=", [1, 3], [2, 3]], ["!", [2, 4], [3, "a"]], ["=", [3, "b"], [4, "b"]]]
Diff::LCS::Changeオブジェクトに使えるメソッド
:<=>, :==, :inspect, :to_a, :new_element, :old_position, :new_position, :old_element, :changed?, :action, :adding?, :deleting?, :unchanged?, :finished_a?, :finished_b?, :<, :>, :<=, :>=, :between?, :tap, :public_send, :instance_variables, :instance_variable_set, :instance_variable_defined?, :remove_instance_variable, :private_methods, :kind_of?, :is_a?, :instance_variable_get, :instance_of?, :public_method, :extend, :define_singleton_method, :singleton_method, :to_enum, :enum_for, :===, :=~, :!~, :eql?, :respond_to?, :freeze, :display, :object_id, :send, :to_s, :method, :nil?, :hash, :class, :singleton_class, :clone, :dup, :itself, :taint, :tainted?, :untaint, :untrust, :trust, :untrusted?, :methods, :protected_methods, :frozen?, :public_methods, :singleton_methods, :!, :!=, :__send__, :equal?, :instance_eval, :instance_exec, :__id__