# frozen_string_literal: true
require 'rubygems'
##
# A collection of text-wrangling methods
module Gem::Text
##
# Remove any non-printable characters and make the text suitable for
# printing.
def clean_text(text)
text.gsub(/[\000-\b\v-\f\016-\037\177]/, ".".freeze)
end
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
##
# Wraps +text+ to +wrap+ characters and optionally indents by +indent+
# characters
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
def min3 a, b, c # :nodoc:
if a < b && a < c then
a
elsif b < c then
b
else
c
end
end
# This code is based directly on the Text gem implementation
# Returns a value representing the "cost" of transforming str1 into str2
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
end
|