Class: IOSegmenter::Parser

Inherits:
Object
  • Object
show all
Defined in:
lib/io-segmenter/parser.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(starting_char, ending_char, quote_char, escape_char) ⇒ Parser

Returns a new instance of Parser.



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# File 'lib/io-segmenter/parser.rb', line 7

def initialize(starting_char, ending_char, quote_char, escape_char)
  @starting_char = starting_char
  @ending_char = ending_char
  @quote_char = quote_char
  @escape_char = escape_char

  terms = [
    @starting_char,
    @ending_char,
    @quote_char,
    @escape_char
  ]
  terms.compact!
  terms.map! { |str| Regexp.escape(str) }

  @search = Regexp.new('(:?' + terms.join('|') + ')')
  @buffer = String.new
end

Instance Attribute Details

#buffer ⇒ Object (readonly)

Returns the value of attribute buffer.



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# File 'lib/io-segmenter/parser.rb', line 5

def buffer
  @buffer
end

Instance Method Details

#each_segment(buffer) ⇒ Object 



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# File 'lib/io-segmenter/parser.rb', line 33

def each_segment(buffer)
  return unless (start_offset = buffer.index(@starting_char))

  brackets = 1
  offset = start_offset

  opened_quote = false

  while (offset = buffer.index(@search, offset + 1))
    case buffer[offset]
    when @ending_char
      next if opened_quote
      brackets -= 1
    when @starting_char
      next if opened_quote
      brackets += 1
    when @quote_char
      opened_quote = !opened_quote
      next
    when @escape_char
      offset += @escape_char.size
      next
    else
      if @ending_char == buffer[offset, @ending_char.size]
        next if opened_quote
        brackets -= 1
      elsif @starting_char == buffer[offset, @starting_char.size]
        next if opened_quote
        brackets += 1
      else
        raise("unhandled offset #{offset}, at #{buffer[offset, 20]}...")
      end
    end

    next unless brackets.zero?

    len = (offset + @ending_char.size) - start_offset
    yield buffer[start_offset, len]
    buffer.slice!(0, offset + @ending_char.size)
    return unless (start_offset = buffer.index(@starting_char))
    offset = start_offset
    brackets = 1
  end
end

#unpack(str) ⇒ Object 



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# File 'lib/io-segmenter/parser.rb', line 26

def unpack(str)
  @buffer << str
  each_segment(@buffer) do |segment|
    yield segment
  end
end