Module: Pray::CLI::Suggest

Defined in:
lib/pray/cli/suggest.rb

Constant Summary collapse

TOP_LEVEL_COMMANDS = 
%w[
  add apply clean confess drift explain fmt format help init install list login manifest
  outdated package plan prayer publish remove render repo serve sync tree trust unlock
  update vendor verify version
].freeze

Class Method Summary collapse

Class Method Details

.levenshtein_distance(left, right) ⇒ Object 



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# File 'lib/pray/cli/suggest.rb', line 30

def levenshtein_distance(left, right)
  left_chars = left.chars
  right_chars = right.chars
  left_length = left_chars.length
  right_length = right_chars.length
  return right_length if left_length.zero?
  return left_length if right_length.zero?

  previous_row = (0..right_length).to_a
  current_row = Array.new(right_length + 1, 0)

  left_chars.each_with_index do |left_character, left_index|
    current_row[0] = left_index + 1
    right_chars.each_with_index do |right_character, right_index|
      substitution_cost = (left_character == right_character) ? 0 : 1
      current_row[right_index + 1] = [
        previous_row[right_index + 1] + 1,
        current_row[right_index] + 1,
        previous_row[right_index] + substitution_cost
      ].min
    end
    previous_row, current_row = current_row, previous_row
  end

  previous_row[right_length]
end

.suggest_command(input, candidates) ⇒ Object 



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# File 'lib/pray/cli/suggest.rb', line 21

def suggest_command(input, candidates)
  maximum_distance = (input.length <= 3) ? 1 : 2
  candidates
    .map { |candidate| [candidate, levenshtein_distance(input, candidate)] }
    .select { |(_, distance)| distance <= maximum_distance }
    .min_by { |(_, distance)| distance }
    &.first
end

.unknown_command_message(command) ⇒ Object 



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# File 'lib/pray/cli/suggest.rb', line 14

def unknown_command_message(command)
  message = "unknown command: #{command}"
  suggestion = suggest_command(command, TOP_LEVEL_COMMANDS)
  message = "#{message}\nDid you mean `#{suggestion}`?" if suggestion
  "#{message}\nSee 'pray --help'."
end