Class: BurrowsWheeler::CircularString

Inherits:
Object
  • Object
show all
Includes:
Comparable
Defined in:
lib/burrows_wheeler/circular_string.rb

Overview

> CircularString.new(str, 5).to_s

> “ADABRA!ABRAC”,

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(string, shift) ⇒ CircularString

Returns a new instance of CircularString.



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# File 'lib/burrows_wheeler/circular_string.rb', line 11

def initialize(string, shift)
  @string = string
  @shift = shift
end

Instance Attribute Details

#shift ⇒ Object (readonly)

Returns the value of attribute shift.



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# File 'lib/burrows_wheeler/circular_string.rb', line 9

def shift
  @shift
end

#string ⇒ Object (readonly)

Returns the value of attribute string.



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# File 'lib/burrows_wheeler/circular_string.rb', line 8

def string
  @string
end

Instance Method Details

#<=>(other) ⇒ Object 



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# File 'lib/burrows_wheeler/circular_string.rb', line 31

def <=>(other)
  len = [length, other.length].min

  (0..len - 1).each do |i|
    c1, c2 = self[i], other[i]
    return (c1 <=> c2) if c1 != c2
  end

  length <=> other.length
end

#[](index) ⇒ Object 



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# File 'lib/burrows_wheeler/circular_string.rb', line 16

def [](index)
  return nil if index < 0 || index >= string.length
  idx = (index + @shift) % @string.length
  @string[idx]
end

#last ⇒ Object 



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# File 'lib/burrows_wheeler/circular_string.rb', line 22

def last
  self[length - 1]
end

#length ⇒ Object 



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# File 'lib/burrows_wheeler/circular_string.rb', line 42

def length
  @string.length
end

#subsequence(start, finish) ⇒ Object 



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# File 'lib/burrows_wheeler/circular_string.rb', line 26

def subsequence(start, finish)
  len = finish - start
  CircularString.new(@string[start, len], @shift)
end

#to_s ⇒ Object 



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# File 'lib/burrows_wheeler/circular_string.rb', line 46

def to_s
  (0..@string.length - 1).reduce('') do |str, idx|
    str + self[idx]
  end
end