diff options
| -rw-r--r-- | activesupport/CHANGELOG | 2 | ||||
| -rw-r--r-- | activesupport/lib/active_support/core_ext/hash/diff.rb | 8 |
2 files changed, 10 insertions, 0 deletions
diff --git a/activesupport/CHANGELOG b/activesupport/CHANGELOG index 4b22b6e7b2..e63915a754 100644 --- a/activesupport/CHANGELOG +++ b/activesupport/CHANGELOG @@ -1,5 +1,7 @@ *SVN* +* Add documentation for Hash#diff. Closes #9306 [tarmo] + * Add new superclass_delegating_accessors. Similar to class inheritable attributes but with subtly different semantics. [Koz, tarmo] * Change JSON to encode %w(< > &) as 4 digit hex codes to be in compliance with the JSON spec. Closes #9975 [josh, chuyeow, tpope] diff --git a/activesupport/lib/active_support/core_ext/hash/diff.rb b/activesupport/lib/active_support/core_ext/hash/diff.rb index deace40a29..6abd678822 100644 --- a/activesupport/lib/active_support/core_ext/hash/diff.rb +++ b/activesupport/lib/active_support/core_ext/hash/diff.rb @@ -2,6 +2,14 @@ module ActiveSupport #:nodoc: module CoreExtensions #:nodoc: module Hash #:nodoc: module Diff + # Returns a hash that represents the difference between two hashes. + # + # Examples: + # + # {1 => 2}.diff(1 => 2) # => {} + # {1 => 2}.diff(1 => 3) # => {1 => 2} + # {}.diff(1 => 2) # => {1 => 2} + # {1 => 2, 3 => 4}.diff(1 => 2) # => {3 => 4} def diff(h2) self.dup.delete_if { |k, v| h2[k] == v }.merge(h2.dup.delete_if { |k, v| self.has_key?(k) }) end |