Class: BfInterpreter

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

Defined Under Namespace

Classes: BfCell, BfProgramUnit

Instance Method Summary collapse

Constructor Details

#initialize(debug = false, wrap_around = true, cell_size = 8) ⇒ BfInterpreter

Returns a new instance of BfInterpreter.



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# File 'lib/yarbf.rb', line 10

def initialize(debug = false, wrap_around = true, cell_size = 8)
  @option = Hash.new
  @option[KEY_DEBUG] = debug
  @option[KEY_WRAP] = wrap_around
  @option[KEY_CELL] = cell_size
end

Instance Method Details

#cell_size=(cell_size) ⇒ Object 



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# File 'lib/yarbf.rb', line 37

def cell_size=(cell_size)
  @option[KEY_CELL] = cell_size
end

#cell_size? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/yarbf.rb', line 33

def cell_size?
  @option[KEY_CELL]
end

#debug=(debug) ⇒ Object 



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# File 'lib/yarbf.rb', line 21

def debug=(debug)
  @option[KEY_DEBUG] = debug
end

#debug? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/yarbf.rb', line 17

def debug?
  @option[KEY_DEBUG]
end

#run(src) ⇒ Object 



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# File 'lib/yarbf.rb', line 41

def run(src)
  units = []

  # construct units
  File.open(src) do |file|
    units = construct_program_units(file)
  end

  # match brackets
  match_brackets(units)

  # do interpret
  tape = Array.new
  position = 0
  unit = units[0]
  while unit != nil
    tape[position] = BfCell.new(position) if tape[position] == nil

    STDERR.printf('%s', unit.instruction) if debug?

    case unit.instruction
      when '+' then tape[position].increase(1, wrap_around?)
      when '-' then tape[position].decrease(1, wrap_around?)
      when '<' then
        position -= 1
        fail 'Cell position out of bound!' if position < 0
      when '>' then position += 1
      when ',' then
        tape[position].value = STDIN.getch.ord
      when '.' then STDOUT.putc tape[position].value
      when '[' then
        if tape[position].value == 0
          unit = unit.match
          next
        end
      when ']' then
        if tape[position].value != 0
          unit = unit.match
          next
        end
      else fail "Illegal instruction '#{unit.instruction}'!"
    end

    unit = unit.next
  end
end

#wrap_around=(wrap_around) ⇒ Object 



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# File 'lib/yarbf.rb', line 29

def wrap_around=(wrap_around)
  @option[KEY_WRAP] = wrap_around
end

#wrap_around? ⇒ Boolean

Returns:

  • (Boolean) 


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

def wrap_around?
  @option[KEY_WRAP]
end