More than 5 years have passed since last update.

JuliaでBrainfuck

Posted at 2016-12-08

function parse_parens(code)
  pos_open = [i for (i, c) in enumerate(code) if c  == '[']
  pos_close = [i for (i, c) in enumerate(code) if c  == ']']
  if length(pos_open) != length(pos_close)
    error("parenthesis mismatch")
  end
  dict_parenspos = Dict(zip(pos_open, reverse(pos_close)))
  return dict_parenspos
end


function brainfuck(code)
  tape = zeros(Int, 30_000)
  tape_ptr = 1
  code_ptr = 1
  dict_parenspos = parse_parens(code)
  stack = []

  while code_ptr < length(code)
    c = code[code_ptr]

    if c == '[' && tape[tape_ptr] == 0
      code_ptr = dict_parenspos[tape_ptr]
    elseif c == '[' && tape[tape_ptr] != 0
      push!(stack, code_ptr)

    elseif c == ']' && tape[tape_ptr] == 0
      pop!(stack)
    elseif c == ']' && tape[tape_ptr] != 0
      code_ptr = pop!(stack) - 1

    elseif c == '>'
      if 30_000 <= tape_ptr
          error("Segmentation fault")
      end
      tape_ptr += 1
    elseif c == '<'
      if tape_ptr <= 0
          error("Segmentation fault")
      end
      tape_ptr -= 1

    elseif c == '+'
      tape[tape_ptr] = mod(tape[tape_ptr] + 1, 256)
    elseif c == '-'
      tape[tape_ptr] = mod(tape[tape_ptr] - 1, 256)
    elseif c == '.'
      print( Char(tape[tape_ptr]) )
    end

    code_ptr += 1
  end
end


code = """
  +++++++++[>++++++++>+++++++++++>+++++<<<-]>.>++.+++++++..+++.>-.
  ------------.<++++++++.--------.+++.------.--------.>+.
  """

brainfuck(code)

こんな感じでしょうか。

参考資料

You get articles that match your needs
You can efficiently read back useful information
You can use dark theme

What you can do with signing up