Class: ICU::Transliteration::Transliterator

Inherits:
Object
  • Object
show all
Defined in:
lib/ffi-icu/transliteration.rb

Instance Method Summary collapse

Constructor Details

#initialize(id, rules = nil, direction = :forward) ⇒ Transliterator

Returns a new instance of Transliterator.



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# File 'lib/ffi-icu/transliteration.rb', line 25

def initialize(id, rules = nil, direction = :forward)
  rules_length = 0

  if rules
    rules_length = rules.size + 1
    rules = UCharPointer.from_string(rules)
  end

  parse_error = Lib::UParseError.new
  begin
    Lib.check_error do |status|
      ptr = Lib.utrans_openU(UCharPointer.from_string(id), id.size, direction, rules, rules_length,
                             @parse_error, status)
      @tr = FFI::AutoPointer.new(ptr, Lib.method(:utrans_close))
    end
  rescue ICU::Error => e
    raise(e, "#{e.message} (#{parse_error})")
  end
end

Instance Method Details

#transliterate(from) ⇒ Object 



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# File 'lib/ffi-icu/transliteration.rb', line 45

def transliterate(from)
  # this is a bit unpleasant

  unicode_size = from.unpack('U*').size
  capacity     = unicode_size + 1
  buf          = UCharPointer.from_string(from, capacity)
  limit        = FFI::MemoryPointer.new(:int32)
  text_length  = FFI::MemoryPointer.new(:int32)

  retried = false

  begin
    # resets to original size on retry
    [limit, text_length].each do |ptr|
      ptr.put_int32(0, unicode_size)
    end

    Lib.check_error do |error|
      Lib.utrans_transUChars(@tr, buf, text_length, capacity, 0, limit, error)
    end
  rescue BufferOverflowError
    new_size = text_length.get_int32(0)
    warn("BufferOverflowError, needs: #{new_size}") if $DEBUG

    raise(BufferOverflowError, "needed #{new_size}") if retried

    capacity = new_size + 1

    # create a new buffer with more capacity instead of resizing,
    # since the old buffer now has result data
    buf.free
    buf = UCharPointer.from_string(from, capacity)

    retried = true
    retry
  end

  buf.string(text_length.get_int32(0))
end