Module: Gemmy::Patches::HashPatch::InstanceMethods::Rekey

Defined in:
lib/gemmy/patches/hash_patch.rb

Instance Method Summary collapse

Instance Method Details

#rekey(key_map = nil, &block) ⇒ Object

facets rekey according to a block, i.e. 1.rekey &:to_s

Raises:

  • (ArgumentError) 


109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
 
# File 'lib/gemmy/patches/hash_patch.rb', line 109

def rekey(key_map=nil, &block)
  raise ArgumentError, "argument or block" if key_map && block

  if !(key_map or block)
    block = lambda{|k| k.to_sym}
  end

  if block
    hash = dup.clear
    if block.arity.abs == 1
      each_pair do |k, v|
        hash[block[k]] = v     #hash[block[k] || k] = v
      end
    else
      each_pair do |k, v|
        hash[block[k,v]] = v   #hash[block[k,v] || k] = v
      end
    end
  else
    #hash = dup.clear  # to keep default_proc
    #(keys - key_map.keys).each do |key|
    #  hash[key] = self[key]
    #end
    #key_map.each do |from, to|
    #  hash[to] = self[from] if key?(from)
    #end
    hash = dup  # to keep default_proc
    key_map.each_pair do |from, to|
      hash[to] = hash.delete(from) if hash.key?(from)
    end
  end

  hash
end