Module: Gem::Text

Relationships & Source Files
Extension / Inclusion / Inheritance Descendants
Extended In: Licenses
Included In: Commands::ListCommand, Commands::QueryCommand, Commands::SearchCommand, SpecFetcher
Defined in:	lib/rubygems/text.rb

Overview

A collection of text-wrangling methods

Instance Method Summary

#clean_text(text)

Remove any non-printable characters and make the text suitable for printing.
#format_text(text, wrap, indent = 0)

Wraps text to wrap characters and optionally indents by indent characters.
#levenshtein_distance(str1, str2)

This code is based directly on the Text gem implementation Returns a value representing the “cost” of transforming str1 into str2.
#truncate_text(text, description, max_length = 100_000)

Instance Method Details

#clean_text(text)

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

[ GitHub ]

# 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)

Wraps text to wrap characters and optionally indents by indent characters

[ GitHub ]

# 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]/ then
      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)

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

[ GitHub ]

# 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)

Raises:

(ArgumentError)

[ GitHub ]

# 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