class DidYouMean::SpellChecker

Public Class Methods

new(dictionary: ) click to toggle source
# File lib/did_you_mean/spell_checker.rb, line 7
def initialize(dictionary: )
  @dictionary = dictionary
end

Public Instance Methods

correct(input) click to toggle source
# File lib/did_you_mean/spell_checker.rb, line 11
def correct(input)
  input     = normalize(input)
  threshold = input.length > 3 ? 0.834 : 0.77

  seed = @dictionary.select {|candidate| JaroWinkler.distance(normalize(candidate), input) >= threshold }
  seed.reject! {|candidate| input == candidate.to_s }
  seed.sort_by! {|candidate| JaroWinkler.distance(candidate.to_s, input) }
  seed.reverse!

  # Correct mistypes
  threshold   = (input.length * 0.25).ceil
  has_mistype = seed.rindex {|c| Levenshtein.distance(normalize(c), input) <= threshold }

  corrections = if has_mistype
    seed.take(has_mistype + 1)
  else
    # Correct misspells
    seed.select do |candidate|
      candidate = normalize(candidate)
      length    = input.length < candidate.length ? input.length : candidate.length

      Levenshtein.distance(candidate, input) < length
    end.first(1)
  end

  corrections
end