Class: ANSEL::Converter

Inherits:
Object
  • Object
show all
Includes:
CharacterMap
Defined in:
lib/ansel/converter.rb

Instance Method Summary collapse

Constructor Details

#initialize(to_charset = 'UTF-8') ⇒ Converter

Returns a new instance of Converter.



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# File 'lib/ansel/converter.rb', line 7

def initialize(to_charset = 'UTF-8')
  @to_charset = to_charset
end

Instance Method Details

#ansi_to_utf16 ⇒ Object 



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# File 'lib/ansel/converter.rb', line 11

def ansi_to_utf16
  @ansi_to_utf16 ||= @@non_combining.merge(@@combining)
end

#convert(string) ⇒ Object 



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# File 'lib/ansel/converter.rb', line 15

def convert(string)
  output = ''
  scanner = StringScanner.new(string)
  until scanner.eos? do
    byte = scanner.get_byte
    char = byte.unpack('C')[0]

    case char
    when 0x00..0x7F
      output << byte.force_encoding('UTF-8')
    when 0x88..0xC8
      hex_key = char.to_s(16).upcase
      output << (ansi_to_utf16[hex_key] || ansi_to_utf16['ERR']).force_encoding('UTF-16BE').encode('UTF-8')
      scanner.get_byte # ignore the next byte
    when 0xE0..0xFB
      [2, 1, 0].each do |n| # try 3 bytes, then 2 bytes, then 1 byte
        bytes = [char.to_s(16).upcase]
        scanner.peek(n).each_byte {|b| bytes << b.to_s(16).upcase}
        hex_key = bytes.join('+')
        if ansi_to_utf16.has_key?(hex_key)
          output << ansi_to_utf16[hex_key].force_encoding('UTF-16BE').encode('UTF-8')
          n.times {scanner.get_byte}
          break
        end
      end
    else
      output << ansi_to_utf16['ERR'].force_encoding('UTF-16BE').encode('UTF-8')
      scanner.get_byte if scanner.get_byte.unpack('C')[0] >= 0xE0 # ignore the next byte
    end
  end

  output.force_encoding('UTF-8')
end