https://cookies.hatenablog.jp/entry/2020/12/29/080000

wasmbfvis.rb

require 'curses'

progs = [
  '-.+',
  '----[---->+<]>--.',
  '--[--->+<]>.++++.------.-[--->+<]>--.+++++[->+++<]>.-.---------.+++++++++++++..---.+++.[-->+<]>++++.+[-->+<]>+++.[--->++<]>.+++.------------.--.--[--->+<]>-.-----------.',
  '++++++.-.[----->++<]>++.+[--->+<]>+++.++++++++++.-------------.+.+++[->+++<]>++.-[--->++<]>-.----[->+++<]>-.++++++++++++..----.[-->+<]>++.-----------..-[--->++<]>--.',
  '-------------.++++++++++++.++++.++[->+++<]>.[--->+<]>----.+.++[->+++<]>.+++++++.+++++.[----->++<]>++.--[-->+++++<]>.---------.[--->+<]>---.[++>---<]>+.-[--->++<]>--.++[++>---<]>+.',
  '---[->++<]>....+[--->+++++<]>.[--->++<]>---.++++.+[--->+<]>.+++++++++++.------------.-[--->+<]>-.--------.--------.+++++++++.++++++.[++>---<]>.--[--->+<]>-.++++++++++++..----.--.----.',
  '+[--->+<]>.--.---[->++++<]>-.-.++++[->+++<]>+.[--->++<]>-----.-[->++<]>.[-->+<]>+.',
  '[-<+]+',
  '>->>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>+>',
]
prog = progs.join

mem = 0.chr*4000
bptr = 1024
mbase = mptr = 1136
# pbase = pptr = 2144
pbase = pptr = 1024 + 256
mem[pptr, prog.size] = prog

step = ->() {
  return false if mem[pptr].ord == 0

  case mem[pptr]
  when '>' then mptr += 1
  when '<' then mptr -= 1
  when '+' then mem[mptr] = ((mem[mptr].ord + 1)%256).chr
  when '-' then mem[mptr] = ((mem[mptr].ord + 255)%256).chr
  when '['
    if mem[mptr] == 0.chr
      dep = 1
      until dep == 0
        pptr += 1
        case mem[pptr]
        when '[' then dep += 1
        when ']' then dep -= 1
        end
      end
    end
  when ']'
    unless mem[mptr] == 0.chr
      dep = 1
      until dep == 0
        pptr -= 1
        case mem[pptr]
        when '[' then dep -= 1
        when ']' then dep += 1
        end
      end
    end
  when '.'
    mem[bptr] = mem[mptr]
    bptr += 1
  else
    raise 'a'
  end

  pptr += 1
  true
}

chr = ->(x) {
  return x.chr if 0x20 <= x && x < 0x7E
  ' '
}

Curses.init_screen
Curses.start_color

NPTR_C = 0; 
MPTR_C = 1; Curses.init_pair(MPTR_C, Curses::COLOR_BLACK, Curses::COLOR_RED)
PPTR_C = 2; Curses.init_pair(PPTR_C, Curses::COLOR_BLACK, Curses::COLOR_GREEN)
BPTR_C = 3; Curses.init_pair(BPTR_C, Curses::COLOR_BLACK, Curses::COLOR_CYAN)

begin
  pk = 0
  ppi = -1
  (0..).each do |k|
    w = 32
    h = 15
    bs = 1024 - 64
    Curses.setpos 0, 0
    Curses.attrset Curses.color_pair(NPTR_C)
    Curses.addstr k.to_s

    Curses.setpos 0, 8
    Curses.attrset Curses.color_pair(BPTR_C)
    Curses.addstr "BUFFER"
    Curses.attrset Curses.color_pair(MPTR_C)
    Curses.addstr "MEMORY"
    Curses.attrset Curses.color_pair(PPTR_C)
    Curses.addstr "PROGRAM"

    pc = -1
    (1...h).each do |i|
      Curses.attrset Curses.color_pair(NPTR_C)
      Curses.setpos i, 0
      Curses.addstr "%04X: " % [bs + i*w]

      w.times do |j|
        addr = bs + i*w + j
        cid = case addr
              when mptr
                MPTR_C
              when bptr
                BPTR_C
              when pptr
                PPTR_C
              else
                NPTR_C
              end
        Curses.attrset Curses.color_pair(cid) unless pc == cid
        pc = cid

        Curses.setpos i, 6 + j*3
        Curses.addstr "%02X" % mem[addr].ord

        Curses.setpos i, 6 + w*3+5 + j
        Curses.addstr chr[mem[addr].ord]
      end
    end

    pi = (progs.size.times.find{|x| progs[0,x].join.size > pptr - pbase} || progs.size) - 1
    pj = pptr - pbase - progs[0,pi].join.size
    begin
      Curses.setpos h+2, 0
      Curses.attrset Curses.color_pair(NPTR_C)
      progs.each do |ln|
        Curses.addstr ln + "\n"
      end
      Curses.setpos h+2+pi, pj
      Curses.attrset Curses.color_pair(PPTR_C)
      Curses.addstr progs[pi][pj]
    end

    Curses.refresh

    sleep 1 if k == 0
    pk = 0 unless ppi == pi
    ppi = pi

    sleep (case
           when pk == 0
             2
           when pk < 5
             0.5
           when pk < 20
             0.1
           when pk < 50
             0.05
           when pk < 100
             0.01
           else
             0
           end
          )

    pk += 1
    break unless step[]
  end
rescue
ensure
  sleep 3
  Curses.close_screen
end