lib/erd_handler/label.rb

   1 class Label
   2
   3   attr_reader :original, :processed
   4
   5   def initialize(original = "")
   6     @original = original
   7     @processed = [original]
   8   end
   9
  10   def split(opts = {})
  11     if opts.class == Regexp
  12       regexp = opts
  13       split_camel_case = true
  14     else
  15       regexp = opts[:regexp] || /[\t\n _,.-]+/
  16       if opts.has_key? :camel_case
  17         split_camel_case = opts[:camel_case]
  18       else
  19         split_camel_case = true
  20       end
  21       if opts.has_key? :numbers
  22         split_numbers = opts[:numbers]
  23       else
  24         split_numbers = true
  25       end
  26     end
  27     @processed = @processed.map do |segment|
  28       segment.split(regexp)
  29     end.flatten
  30
  31     if split_camel_case
  32       @processed = @processed.map do |segment|
  33         segment.split(/(?<=[a-z])(?=[A-Z])/)
  34       end.flatten
  35     end
  36
  37     if split_numbers
  38       @processed = @processed.map do |segment|
  39         segment.split(/(?:(?<!\d)(?=\d))|(?:(?<=\d)(?!\d))/)
  40       end.flatten
  41     end
  42     self
  43   end
  44
  45   def downcase
  46     @processed = @processed.map do |segment| segment.downcase end
  47     self
  48   end
  49
  50   def stem(gb_english = false)
  51     @processed = @processed.map do |segment| segment.stem(gb_english) end
  52     self
  53   end
  54
  55   def tidy
  56     self.split.downcase.stem
  57   end
  58
  59   def levenshtein(other_object)
  60     if other_object.class == Label
  61       other = other_object.processed.join('')
  62     else
  63       other = other_object
  64     end
  65     s = @processed.join('')
  66     n = s.length
  67     m = other.length
  68     return m if (0 == n)
  69     return n if (0 == m)
  70
  71     d = Array.new(m+1) {Array.new(n+1, 0)} # one row for each characer in other, one column for each charater in self
  72
  73     (0..n).each {|i| d[0][i] = i}
  74     (0..m).each {|j| d[j][0] = j}
  75     (1..m).each do |i|
  76       (1..n).each do |j|
  77         d[i][j] = [d[i-1][j-1] + ((s[j-1] == other[i-1]) ? 0 : 1),  # substitution
  78                    d[i-1][j] + 1, # deletion
  79                    d[i][j-1] + 1  # addition
  80                    ].min
  81       end
  82     end
  83     d[-1][-1]
  84   end
  85
  86   alias :edit_distance :levenshtein
  87 end