Module: Gem::Text

Included in:
Commands::QueryCommand, Licenses, SpecFetcher
Defined in:
lib/rubygems/text.rb

Overview

A collection of text-wrangling methods

Instance Method Summary collapse

Instance Method Details

#clean_text(text) ⇒ Object

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


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# 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) ⇒ Object

Wraps text to wrap characters and optionally indents by indent characters


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# 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) ⇒ Object

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


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# 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

#min3(a, b, c) ⇒ Object

:nodoc:


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# File 'lib/rubygems/text.rb', line 43

def min3 a, b, c # :nodoc:
  if a < b && a < c then
    a
  elsif b < c then
    b
  else
    c
  end
end

#truncate_text(text, description, max_length = 100_000) ⇒ Object

Raises:

  • (ArgumentError)

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# 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