diff options
| -rw-r--r-- | activesupport/lib/active_support/core_ext/hash/reverse_merge.rb | 20 |
1 files changed, 7 insertions, 13 deletions
diff --git a/activesupport/lib/active_support/core_ext/hash/reverse_merge.rb b/activesupport/lib/active_support/core_ext/hash/reverse_merge.rb index 87a7bebd7b..01863a162b 100644 --- a/activesupport/lib/active_support/core_ext/hash/reverse_merge.rb +++ b/activesupport/lib/active_support/core_ext/hash/reverse_merge.rb @@ -1,25 +1,19 @@ class Hash - # Allows for reverse merging two hashes where the keys in the calling hash take precedence over those - # in the <tt>other_hash</tt>. This is particularly useful for initializing an option hash with default values: + # Merges the caller into +other_hash+. For example, # - # def setup(options = {}) - # options.reverse_merge! :size => 25, :velocity => 10 - # end + # options = options.reverse_merge(:size => 25, :velocity => 10) # - # The default <tt>:size</tt> and <tt>:velocity</tt> are only set if the +options+ hash passed in doesn't already - # have the respective key. + # is equivalent to # - # As contrast, using Ruby's built in <tt>merge</tt> would require writing the following: + # options = {:size => 25, :velocity => 10}.merge(options) # - # def setup(options = {}) - # options = { :size => 25, :velocity => 10 }.merge(options) - # end + # This is particularly useful for initializing an options hash + # with default values. def reverse_merge(other_hash) other_hash.merge(self) end - # Performs the opposite of <tt>merge</tt>, with the keys and values from the first hash taking precedence over the second. - # Modifies the receiver in place. + # Destructive +reverse_merge+. def reverse_merge!(other_hash) # right wins if there is no left merge!( other_hash ){|key,left,right| left } |