Froze rails gems

[depot.git] / vendor / rails / activesupport / lib / active_support / core_ext / enumerable.rb

diff --git a/vendor/rails/activesupport/lib/active_support/core_ext/enumerable.rb b/vendor/rails/activesupport/lib/active_support/core_ext/enumerable.rb
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+++ b/vendor/rails/activesupport/lib/active_support/core_ext/enumerable.rb
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+require 'active_support/ordered_hash'
+
+module Enumerable
+  # Ruby 1.8.7 introduces group_by, but the result isn't ordered. Override it.
+  remove_method(:group_by) if [].respond_to?(:group_by) && RUBY_VERSION < '1.9'
+
+  # Collect an enumerable into sets, grouped by the result of a block. Useful,
+  # for example, for grouping records by date.
+  #
+  # Example:
+  #
+  #   latest_transcripts.group_by(&:day).each do |day, transcripts| 
+  #     p "#{day} -> #{transcripts.map(&:class).join(', ')}"
+  #   end
+  #   "2006-03-01 -> Transcript"
+  #   "2006-02-28 -> Transcript"
+  #   "2006-02-27 -> Transcript, Transcript"
+  #   "2006-02-26 -> Transcript, Transcript"
+  #   "2006-02-25 -> Transcript"
+  #   "2006-02-24 -> Transcript, Transcript"
+  #   "2006-02-23 -> Transcript"
+  def group_by
+    assoc = ActiveSupport::OrderedHash.new
+
+    each do |element|
+      key = yield(element)
+
+      if assoc.has_key?(key)
+        assoc[key] << element
+      else
+        assoc[key] = [element]
+      end
+    end
+
+    assoc
+  end unless [].respond_to?(:group_by)
+
+  # Calculates a sum from the elements. Examples:
+  #
+  #  payments.sum { |p| p.price * p.tax_rate }
+  #  payments.sum(&:price)
+  #
+  # The latter is a shortcut for:
+  #
+  #  payments.inject { |sum, p| sum + p.price }
+  #
+  # It can also calculate the sum without the use of a block.
+  #
+  #  [5, 15, 10].sum # => 30
+  #  ["foo", "bar"].sum # => "foobar"
+  #  [[1, 2], [3, 1, 5]].sum => [1, 2, 3, 1, 5]
+  #
+  # The default sum of an empty list is zero. You can override this default:
+  #
+  #  [].sum(Payment.new(0)) { |i| i.amount } # => Payment.new(0)
+  #
+  def sum(identity = 0, &block)
+    return identity unless size > 0
+
+    if block_given?
+      map(&block).sum
+    else
+      inject { |sum, element| sum + element }
+    end
+  end
+
+  # Iterates over a collection, passing the current element *and* the
+  # +memo+ to the block. Handy for building up hashes or
+  # reducing collections down to one object. Examples:
+  #
+  #   %w(foo bar).each_with_object({}) { |str, hsh| hsh[str] = str.upcase } #=> {'foo' => 'FOO', 'bar' => 'BAR'}
+  #
+  # *Note* that you can't use immutable objects like numbers, true or false as
+  # the memo. You would think the following returns 120, but since the memo is
+  # never changed, it does not.
+  #
+  #   (1..5).each_with_object(1) { |value, memo| memo *= value } # => 1
+  #
+  def each_with_object(memo, &block)
+    returning memo do |m|
+      each do |element|
+        block.call(element, m)
+      end
+    end
+  end unless [].respond_to?(:each_with_object)
+
+  # Convert an enumerable to a hash. Examples:
+  #
+  #   people.index_by(&:login)
+  #     => { "nextangle" => <Person ...>, "chade-" => <Person ...>, ...}
+  #   people.index_by { |person| "#{person.first_name} #{person.last_name}" }
+  #     => { "Chade- Fowlersburg-e" => <Person ...>, "David Heinemeier Hansson" => <Person ...>, ...}
+  # 
+  def index_by
+    inject({}) do |accum, elem|
+      accum[yield(elem)] = elem
+      accum
+    end
+  end
+  
+  # Returns true if the collection has more than 1 element. Functionally equivalent to collection.size > 1.
+  # Works with a block too ala any?, so people.many? { |p| p.age > 26 } # => returns true if more than 1 person is over 26.
+  def many?(&block)
+    size = block_given? ? select(&block).size : self.size
+    size > 1
+  end
+end