Class: Solitaire::Cipher

Inherits:
Object show all
Defined in:
lib/quiz1/t/solutions/Moses Hohman/cipher.rb

Constant Summary collapse

ENCRYPTED_TEXT_PATTERN = 
/\A[A-Z]{5}( [A-Z]{5})*\Z/

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(text, deck = Deck.new) ⇒ Cipher

Returns a new instance of Cipher.



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# File 'lib/quiz1/t/solutions/Moses Hohman/cipher.rb', line 74

def initialize(text, deck=Deck.new)
	@chunker = Chunker.new(text)
	keystream = Keystream.new(deck)
	@keystream_chunker = Chunker.new(keystream.keystream_letters(@chunker.chunks).join)
	if text =~ ENCRYPTED_TEXT_PATTERN
		@mode = "decrypt"
		@calc_number = proc { |num, keystream_num| num - keystream_num }
	else
		@mode = "encrypt"
		@calc_number = proc { |num, keystream_num| num + keystream_num }
	end
end

Instance Attribute Details

#mode ⇒ Object (readonly)

Returns the value of attribute mode.



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# File 'lib/quiz1/t/solutions/Moses Hohman/cipher.rb', line 86

def mode
  @mode
end

Instance Method Details

#crypt ⇒ Object 



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# File 'lib/quiz1/t/solutions/Moses Hohman/cipher.rb', line 88

def crypt
	ciphered = [@chunker.number_chunks, @keystream_chunker.number_chunks].collect_peel do |num_chunk, keystream_num_chunk|
		[num_chunk, keystream_num_chunk].collect_peel do |num, keystream_num|
			@calc_number.call(num,keystream_num).offset_mod(ALPHABET_SIZE)
		end
	end
	Chunker.to_letters(ciphered).join(" ").rstrip
end