Class: JSON::Expect::Buffer

Inherits:
Object
  • Object
show all
Defined in:
lib/json/expect/parser.rb

Instance Method Summary collapse

Constructor Details

#initialize(input, size) ⇒ Buffer

Returns a new instance of Buffer.



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# File 'lib/json/expect/parser.rb', line 7

def initialize(input, size)
  unless 0 < size
    raise ArgumentError, "negative buffer_size"
  end
  @io = case input
  when String
    StringIO.new(input)
  when IO, StringIO
    input
  else
    raise ArgumentError, "#{input.class} is not supported"
  end
  @string = String.new
  @index = 0
  @size = size
end

Instance Method Details

#back(len = 1) ⇒ Object 



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# File 'lib/json/expect/parser.rb', line 50

def back(len = 1)
  @index -= len
end

#fetch(len = 0) ⇒ Object 



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# File 'lib/json/expect/parser.rb', line 24

def fetch(len = 0)
  if str = @io.read(@size + len)
    @string = @string[@index..-1] << str
    @index = 0
  else
    nil
  end
end

#next(len = 1) ⇒ Object 



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# File 'lib/json/expect/parser.rb', line 33

def next(len = 1)
  if @string.length - @index < len
    if str = @io.read(@size + len)
      @string = @string[@index..-1] << str
      @index = 0
    end
  end

  if @string.length <= @index
    nil
  else
    r = @string[@index, len]
    @index += r.length
    r
  end
end

#next_without_whitespace ⇒ Object 



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# File 'lib/json/expect/parser.rb', line 63

def next_without_whitespace
  while ch = self.next
    case ch
    when " ", "\t", "\n", "\r"
    else
      return ch
    end
  end
end

#rewind ⇒ Object 



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# File 'lib/json/expect/parser.rb', line 73

def rewind
  @string.clear
  @index = 0
  @io.rewind
end

#scan(regexp) ⇒ Object 



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# File 'lib/json/expect/parser.rb', line 54

def scan(regexp)
  if m = regexp.match(@string, @index)
    @index += m[0].length
    m[0]
  else
    nil
  end
end