Method: Hash#alias!

Defined in:

lib/core/facets/hash/alias.rb

#alias!(newkey, oldkey) ⇒ Object

Modifies the receiving Hash so that the value previously referred to by oldkey is also referenced by newkey; oldkey is retained in the Hash. If oldkey does not exist as a key in the Hash, no change is effected.

Returns a reference to the Hash.

foo = { :name=>'Gavin', 'wife'=>:Lisa }
foo.alias!('name',:name)     #=> { :name=>'Gavin', 'name'=>'Gavin', 'wife'=>:Lisa }

foo = { :name=>'Gavin', 'wife'=>:Lisa }
foo.alias!('spouse','wife')  #=> { :name=>'Gavin', 'wife'=>:Lisa, 'spouse'=>:Lisa }

foo = { :name=>'Gavin', 'wife'=>:Lisa }
foo.alias!('bar','foo')      #=> { :name=>'Gavin', 'wife'=>:Lisa }

Note that if the oldkey is reassigned, the reference will no longer exist, and the newkey will remain as it was.

CREDIT: Gavin Sinclair

TODO: Rename to #aliaskey or something else.

# File 'lib/core/facets/hash/alias.rb', line 25

def alias!(newkey, oldkey)
  self[newkey] = self[oldkey] if self.has_key?(oldkey)
  self
end