diff options
Diffstat (limited to 'activesupport/lib/active_support/core_ext/hash/reverse_merge.rb')
-rw-r--r-- | activesupport/lib/active_support/core_ext/hash/reverse_merge.rb | 23 |
1 files changed, 9 insertions, 14 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 d7ebd5feef..01863a162b 100644 --- a/activesupport/lib/active_support/core_ext/hash/reverse_merge.rb +++ b/activesupport/lib/active_support/core_ext/hash/reverse_merge.rb @@ -1,27 +1,22 @@ 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) # - # Using <tt>merge</tt>, the above example would look as follows: + # is equivalent to # - # def setup(options = {}) - # { :size => 25, :velocity => 10 }.merge(options) - # end + # options = {:size => 25, :velocity => 10}.merge(options) # - # 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. + # 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) - merge!( other_hash ){|k,o,n| o } + # right wins if there is no left + merge!( other_hash ){|key,left,right| left } end alias_method :reverse_update, :reverse_merge! |