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Contents
require 'facets/symbol/to_proc'
class Hash
# Rekey a hash.
#
# rekey()
# rekey(to_key, from_key)
# rekey{ |key| ... }
#
# If no arguments or block are given, then all keys are converted
# to Symbols.
#
# If two keys are given, then the second key is changed to
# the first. You can think of it as +alias+ for hash keys.
#
# foo = { :a=>1, :b=>2 }
# foo.rekey('a',:a) #=> { 'a'=>1, :b=>2 }
# foo.rekey('b',:b) #=> { 'a'=>1, 'b'=>2 }
# foo.rekey('foo','bar') #=> { 'a'=>1, 'b'=>2 }
#
# If a block is given, converts all keys in the Hash accroding
# to the given block. If the block returns +nil+ for given key,
# then that key will be left intact.
#
# foo = { :name=>'Gavin', :wife=>:Lisa }
# foo.rekey{ |k| k.to_s } #=> { "name"=>"Gavin", "wife"=>:Lisa }
# foo.inspect #=> { :name =>"Gavin", :wife=>:Lisa }
#
# CREDIT: Trans, Gavin Kistner
def rekey(*args, &block)
dup.rekey!(*args, &block)
end
# Synonym for Hash#rekey, but modifies the receiver in place (and returns it).
#
# foo = { :name=>'Gavin', :wife=>:Lisa }
# foo.rekey!{ |k| k.to_s } #=> { "name"=>"Gavin", "wife"=>:Lisa }
# foo.inspect #=> { "name"=>"Gavin", "wife"=>:Lisa }
#
# CREDIT: Trans, Gavin Kistner
def rekey!(*args, &block)
# for backward comptability (TODO: DEPRECATE).
block = args.pop.to_sym.to_proc if args.size == 1
# if no args use block.
if args.empty?
block = lambda{|k| k.to_sym} unless block
keys.each do |k|
nk = block[k]
self[nk]=delete(k) if nk
end
else
raise ArgumentError, "3 for 2" if block
to, from = *args
self[to] = self.delete(from) if self.has_key?(from)
end
self
end
end
Version data entries
10 entries across 10 versions & 1 rubygems