Class: Treat::Workers::Extractors::Distance::Levenshtein

Inherits:
Object
  • Object
show all
Defined in:
lib/treat/workers/extractors/distance/levenshtein.rb

Overview

The C extension uses char* strings, and so Unicode strings will give incorrect distances. Need to provide a pure implementation if that’s the case (FIX).

Constant Summary collapse

DefaultOptions = 
{
  ins_cost: 1,
  del_cost: 1,
  sub_cost: 1
}
@@matcher = 
nil

Class Method Summary collapse

Class Method Details

.distance(entity, options) ⇒ Object

Return the levensthein distance between two strings taking into account the costs of insertion, deletion, and substitution.



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# File 'lib/treat/workers/extractors/distance/levenshtein.rb', line 19

def self.distance(entity, options)

  options = DefaultOptions.merge(options)

  unless options[:to]
    raise Treat::Exception, "Must supply " +
    "a string/entity to compare to using " +
    "the option :to for this worker."
  end
  
  a, b = entity.to_s, options[:to].to_s

  Levenshtein.distance(a, b)

end