Class: Brainfuckrb::Brainfuck

Inherits:
Object
  • Object
show all
Defined in:
lib/brainfuckrb.rb

Instance Method Summary collapse

Constructor Details

#initialize(program) ⇒ Brainfuck

Returns a new instance of Brainfuck.



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# File 'lib/brainfuckrb.rb', line 7

def initialize(program)
  @program = program
  reset
end

Instance Method Details

#_run(stop = nil) ⇒ Object 



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# File 'lib/brainfuckrb.rb', line 25

def _run(stop = nil)
  stop ||= @program.length

  while @pc < stop
    case @program[@pc].chr
      when ">" then @p += 1
      when "<" then @p -= 1
      when "+" then @mem[@p] += 1
      when "-" then @mem[@p] -= 1
      when "." then STDOUT.putc @mem[@p].chr
      when "," then @mem[@p] = STDIN.readchar.ord
      when "["
        depth = 1
        start = _end = @pc
        while depth != 0
            _end += 1
            depth += 1 if @program[_end] == "["
            depth -= 1 if @program[_end] == "]"
        end
        while @mem[@p] != 0
            @pc = start + 1 
            _run(_end)
        end
        @pc = _end
      when "]" then raise "x:y: not expecting \']\'" 
    end
    @pc += 1
  end
end

#reset ⇒ Object 



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# File 'lib/brainfuckrb.rb', line 12

def reset
  @mem = [0] * 65535
  @p = 0
  @pc = 0
end

#run(stop = nil) ⇒ Object 



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# File 'lib/brainfuckrb.rb', line 18

def run(stop = nil)
  _run(stop)
  result = @mem[@p]
  reset
  return result
end