IdentityParade

gem 'identity_parade'

# Checks the similarity between to arguments. Returns a number between
# 0 and 1. 0 is no similarity and 1 is a complete duplicate.
IdentityParade.match(arg1, arg2)
# => 0.95

# When matching score is equal or greater than the global +matching_score+
# it returns true - otherwise false.
IdentityParade.match?(arg1, arg2)
# => true

IdentityParade.match(1, 1)
=> 1
IdentityParade.match(1, 0)
=> 0.0

IdentityParade.match("hello", "hello")
=> 1.0
IdentityParade.match("hello", "hallo")
=> 0.88
IdentityParade.match("a", "z")
=> 0.0

IdentityParade.match([1, 2, 'foo', { a: 'b'}], [1, 2, 'foo', { a: 'b' }])
=> 1.0
IdentityParade.match([1, 2, 'foo', { a: 'b'}], [1, 3, 'foo', { a: 'b' }])
=> 0.75
IdentityParade.match([1, 2, 'foo', { foo: 'bar'}], [])
=> 0.0

IdentityParade.match({ a: 'b', c: 'd'}, { a: 'b', c: 'd'})
=> 1.0
IdentityParade.match({ a: 'b', c: 'd'}, { a: 'b', c: 'e'})
=> 0.5
IdentityParade.match({ a: 'b', c: 'd'}, { a: 'x', c: 'y'})
=> 0.0

IdentityParade.configure do |config|
  # Blacklist some keys in a hash that should not be compared.
  config.blacklisted_keys = %w[id created_at updated_at]
  # Set the global match score to 80%
  config.match_score = 0.80
end

module IdentityParade
  module Matchers
    class FoobarMatcher < Matcher
      def score
        # You can access the first given object as +left+ and the
        # other as +right+:

        # When #some_value is the same we have a match
        return 1 if left.some_value == right.some_value

        # Do some more complicated stuff here.

        # If there is no similarity at all return 0
        0
      end
    end
  end
end