File: casefold.rb

package info (click to toggle)
ruby-unicode-utils 1.4.0-2
  • links: PTS, VCS
  • area: main
  • in suites: bookworm, bullseye, forky, sid, trixie
  • size: 1,988 kB
  • sloc: ruby: 1,877; makefile: 4
file content (34 lines) | stat: -rw-r--r-- 926 bytes parent folder | download
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
# -*- encoding: utf-8 -*-

require "unicode_utils/read_cdata"
require "unicode_utils/simple_casefold"

module UnicodeUtils

  CASEFOLD_F_MAP = Impl.read_multivalued_map("casefold_f_map") # :nodoc:

  # Perform full case folding. The returned string may be longer than
  # +str+. The purpose of case folding is case insensitive string
  # comparison.
  #
  # Examples:
  #
  #   require "unicode_utils/casefold"
  #   UnicodeUtils.casefold("Ümit") == UnicodeUtils.casefold("ümit") => true
  #   UnicodeUtils.casefold("WEISS") == UnicodeUtils.casefold("weiß") => true
  def casefold(str)
    String.new.force_encoding(str.encoding).tap do |res|
      str.each_codepoint { |cp|
        if mapping = CASEFOLD_C_MAP[cp]
          res << mapping
        elsif mapping = CASEFOLD_F_MAP[cp]
          mapping.each { |m| res << m }
        else
          res << cp
        end
      }
    end
  end
  module_function :casefold

end