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authorJari Vetoniemi <jari.vetoniemi@indooratlas.com>2020-03-16 18:49:26 +0900
committerJari Vetoniemi <jari.vetoniemi@indooratlas.com>2020-03-30 00:39:06 +0900
commitfcbf63e62c627deae76c1b8cb8c0876c536ed811 (patch)
tree64cb17de3f41a2b6fef2368028fbd00349946994 /jni/ruby/lib/rubygems/text.rb
Fresh start
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diff --git a/jni/ruby/lib/rubygems/text.rb b/jni/ruby/lib/rubygems/text.rb
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+require 'rubygems'
+
+##
+# A collection of text-wrangling methods
+
+module Gem::Text
+
+ ##
+ # Wraps +text+ to +wrap+ characters and optionally indents by +indent+
+ # characters
+
+ def format_text(text, wrap, indent=0)
+ result = []
+ work = text.dup
+
+ 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
+ max = n/2
+
+ return m if (0 == n)
+ return n if (0 == m)
+ return n if (n - m).abs > max
+
+ 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
+