Class: ErrorToCommunicate::Levenshtein

Inherits:
Object
  • Object
show all
Defined in:
lib/error_to_communicate/levenshtein.rb

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(target, actual) ⇒ Levenshtein

Returns a new instance of Levenshtein.



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# File 'lib/error_to_communicate/levenshtein.rb', line 8

def initialize(target, actual)
  self.target   = target
  self.actual   = actual
  self.memoized = {}
end

Instance Attribute Details

#actual ⇒ Object

Returns the value of attribute actual.



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# File 'lib/error_to_communicate/levenshtein.rb', line 7

def actual
  @actual
end

#memoized ⇒ Object

Returns the value of attribute memoized.



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# File 'lib/error_to_communicate/levenshtein.rb', line 7

def memoized
  @memoized
end

#target ⇒ Object

Returns the value of attribute target.



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# File 'lib/error_to_communicate/levenshtein.rb', line 7

def target
  @target
end

Class Method Details

.call(target, actual) ⇒ Object 



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# File 'lib/error_to_communicate/levenshtein.rb', line 3

def self.call(target, actual)
  new(target, actual).distance
end

Instance Method Details

#call(target_length, actual_length) ⇒ Object 



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# File 'lib/error_to_communicate/levenshtein.rb', line 18

def call(target_length, actual_length)
  memoized[[target_length, actual_length]] ||=
    if target_length.zero?
      actual_length
    elsif actual_length.zero?
      target_length
    elsif target[target_length - 1] == actual[actual_length - 1]
      call(target_length - 1, actual_length - 1)
    else
      [ call(target_length    , actual_length - 1),
        call(target_length - 1, actual_length    ),
        call(target_length - 1, actual_length - 1),
      ].min + 1
    end
end

#distance ⇒ Object 



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# File 'lib/error_to_communicate/levenshtein.rb', line 14

def distance
  @distance ||= call target.length, actual.length
end