diff options
Diffstat (limited to 'activesupport/lib/active_support/core_ext/enumerable.rb')
| -rw-r--r-- | activesupport/lib/active_support/core_ext/enumerable.rb | 86 |
1 files changed, 17 insertions, 69 deletions
diff --git a/activesupport/lib/active_support/core_ext/enumerable.rb b/activesupport/lib/active_support/core_ext/enumerable.rb index ddb4f3012f..02d5a7080f 100644 --- a/activesupport/lib/active_support/core_ext/enumerable.rb +++ b/activesupport/lib/active_support/core_ext/enumerable.rb @@ -1,42 +1,5 @@ -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 - return to_enum :group_by unless block_given? - 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: + # Calculates a sum from the elements. # # payments.sum { |p| p.price * p.tax_rate } # payments.sum(&:price) @@ -48,7 +11,7 @@ module Enumerable # It can also calculate the sum without the use of a block. # # [5, 15, 10].sum # => 30 - # ["foo", "bar"].sum # => "foobar" + # ['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: @@ -63,28 +26,7 @@ module Enumerable 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) - return to_enum :each_with_object, memo unless block_given? - each do |element| - yield element, memo - end - memo - end unless [].respond_to?(:each_with_object) - - # Convert an enumerable to a hash. Examples: + # Convert an enumerable to a hash. # # people.index_by(&:login) # => { "nextangle" => <Person ...>, "chade-" => <Person ...>, ...} @@ -92,12 +34,15 @@ module Enumerable # => { "Chade- Fowlersburg-e" => <Person ...>, "David Heinemeier Hansson" => <Person ...>, ...} # def index_by - return to_enum :index_by unless block_given? - Hash[map { |elem| [yield(elem), elem] }] + if block_given? + Hash[map { |elem| [yield(elem), elem] }] + else + to_enum :index_by + end end # Returns true if the enumerable has more than 1 element. Functionally equivalent to enum.to_a.size > 1. - # Can be called with a block too, much like any?, so people.many? { |p| p.age > 26 } returns true if more than 1 person is over 26. + # Can be called with a block too, much like any?, so <tt>people.many? { |p| p.age > 26 }</tt> returns true if more than one person is over 26. def many? cnt = 0 if block_given? @@ -106,11 +51,11 @@ module Enumerable cnt > 1 end else - any?{ (cnt += 1) > 1 } + any? { (cnt += 1) > 1 } end end - # The negative of the Enumerable#include?. Returns true if the collection does not include the object. + # The negative of the <tt>Enumerable#include?</tt>. Returns true if the collection does not include the object. def exclude?(object) !include?(object) end @@ -120,8 +65,11 @@ class Range #:nodoc: # Optimize range sum to use arithmetic progression if a block is not given and # we have a range of numeric values. def sum(identity = 0) - return super if block_given? || !(first.instance_of?(Integer) && last.instance_of?(Integer)) - actual_last = exclude_end? ? (last - 1) : last - (actual_last - first + 1) * (actual_last + first) / 2 + if block_given? || !(first.instance_of?(Integer) && last.instance_of?(Integer)) + super + else + actual_last = exclude_end? ? (last - 1) : last + (actual_last - first + 1) * (actual_last + first) / 2 + end end end |