module Gem::Text

A collection of text-wrangling methods

Public Instance Methods

clean_text(text) click to toggle source

Remove any non-printable characters and make the text suitable for printing.

# File lib/rubygems/text.rb, line 12
def clean_text(text)
  text.gsub(/[\000-\b\v-\f\016-\037\177]/, ".".freeze)
end
format_text(text, wrap, indent=0) click to toggle source

Wraps text to wrap characters and optionally indents by indent characters

# File lib/rubygems/text.rb, line 26
def format_text(text, wrap, indent=0)
  result = []
  work = clean_text(text)

  while work.length > wrap do
    if work =~ /^(.{0,#{wrap}})[ \n]/
      result << $1.rstrip
      work.slice!(0, $&.length)
    else
      result << work.slice!(0, wrap)
    end
  end

  result << work if work.length.nonzero?
  result.join("\n").gsub(/^/, " " * indent)
end
levenshtein_distance(str1, str2) click to toggle source

This code is based directly on the Text gem implementation Returns a value representing the “cost” of transforming str1 into str2

# File lib/rubygems/text.rb, line 55
def levenshtein_distance(str1, str2)
  s = str1
  t = str2
  n = s.length
  m = t.length

  return m if (0 == n)
  return n if (0 == m)

  d = (0..m).to_a
  x = nil

  str1.each_char.each_with_index do |char1,i|
    e = i + 1

    str2.each_char.each_with_index do |char2,j|
      cost = (char1 == char2) ? 0 : 1
      x = min3(
           d[j + 1] + 1, # insertion
           e + 1,      # deletion
           d[j] + cost # substitution
         )
      d[j] = e
      e = x
    end

    d[m] = x
  end

  return x
end
truncate_text(text, description, max_length = 100_000) click to toggle source
# File lib/rubygems/text.rb, line 16
def truncate_text(text, description, max_length = 100_000)
  raise ArgumentError, "max_length must be positive" unless max_length > 0
  return text if text.size <= max_length
  "Truncating #{description} to #{max_length.to_s.reverse.gsub(/...(?=.)/,'\&,').reverse} characters:\n" + text[0, max_length]
end