Class: TofuKey

Inherits:
Object
  • Object
show all
Defined in:
lib/tofuhash/tofukey.rb

Overview

TofuKey

Links:

For use with TofuHash. A wrapper for the key of a Hash which will alter the behavior of keys. The behavior provided by default is case-insensitive, and indifferent access for strings and symbols. By subclassing TofuHash, you can create your own behavior.

License:

(The MIT License + Free Software Foundation Advertising Prohibition)

Copyright © 2007 Gregory N. Houston

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Except as contained in this notice, the name(s) of the above copyright holders shall not be used in advertising or otherwise to promote the sale, use or other dealings in this Software without prior written authorization.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(key) ⇒ TofuKey

preserve the key (Strings are cloned and frozen just like Hash’s behavior); then encodes the key for fast comparison



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# File 'lib/tofuhash/tofukey.rb', line 43

def initialize( key )
  if key.instance_of? String
    @original_key = key.clone.freeze
  else
    @original_key = key
  end
  encode
end

Instance Attribute Details

#coded_key ⇒ Object (readonly)

Returns the value of attribute coded_key.



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# File 'lib/tofuhash/tofukey.rb', line 40

def coded_key
  @coded_key
end

#original_key ⇒ Object (readonly)

Returns the value of attribute original_key.



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# File 'lib/tofuhash/tofukey.rb', line 40

def original_key
  @original_key
end

Instance Method Details

#<=>(obj) ⇒ Object 



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# File 'lib/tofuhash/tofukey.rb', line 95

def <=> obj
  if obj.instance_of? Symbol
    @coded_key <=> obj.to_s.downcase
  elsif obj.instance_of? TofuKey
    @coded_key <=> obj.coded_key
  elsif obj.respond_to? :downcase
    @coded_key <=> obj.downcase
  else
    @coded_key <=> obj
  end
end

#==(obj) ⇒ Object 



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# File 'lib/tofuhash/tofukey.rb', line 91

def == obj
  self.eql? obj
end

#decode ⇒ Object

returns the preserved key



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# File 'lib/tofuhash/tofukey.rb', line 65

def decode
  @original_key
end

#encode ⇒ Object

stores a @coded_key which is used for quick comparison and as the hash key. the default encoding will convert Symbols to downcased strings; anything responding to downcase is converted via downcase.



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# File 'lib/tofuhash/tofukey.rb', line 54

def encode
  if @original_key.instance_of? Symbol
    @coded_key = @original_key.to_s.downcase
  elsif @original_key.respond_to? :downcase
    @coded_key = @original_key.downcase
  else
    @coded_key = @original_key
  end
end

#eql?(obj) ⇒ Boolean

compares the encoded key to another object.

given symbols are converted to downcase strings before comparison. given objects which respond to downcase are downcased before comparison. given TofuKey will compare the encoded keys.

Returns:

  • (Boolean) 


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# File 'lib/tofuhash/tofukey.rb', line 79

def eql? obj
  if obj.instance_of? Symbol
    @coded_key.eql?( obj.to_s.downcase )
  elsif obj.instance_of? TofuKey
    @coded_key.eql?( obj.coded_key )
  elsif obj.respond_to? :downcase
    @coded_key.eql?( obj.downcase )
  else
    @coded_key.eql?( obj )
  end
end

#hash ⇒ Object

get the hash of the key, which calls #hash on the encoded key.



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# File 'lib/tofuhash/tofukey.rb', line 70

def hash
  @coded_key.hash
end