Class: BrainLove::VM

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

Constant Summary collapse

NOOP = 
0
INC_DP = 
1
DEC_DP = 
2
INC_BYTE = 
3
DEC_BYTE = 
4
PUTC = 
5
GETC = 
6
JMPFZ = 
7
JMPBNZ = 
8

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(code, input, output) ⇒ VM

Returns a new instance of VM.



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# File 'lib/brain_love/vm.rb', line 16

def initialize(code, input, output)
  @code, @input, @output = code, input, output
  @ip = 0
  @dp = 0
  @data = [0] * 30_000
end

Instance Attribute Details

#code ⇒ Object (readonly)

Returns the value of attribute code.



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# File 'lib/brain_love/vm.rb', line 14

def code
  @code
end

#data ⇒ Object (readonly)

Returns the value of attribute data.



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# File 'lib/brain_love/vm.rb', line 14

def data
  @data
end

#dp ⇒ Object (readonly)

Returns the value of attribute dp.



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# File 'lib/brain_love/vm.rb', line 14

def dp
  @dp
end

#ip ⇒ Object (readonly)

Returns the value of attribute ip.



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# File 'lib/brain_love/vm.rb', line 14

def ip
  @ip
end

Instance Method Details

#code_dump ⇒ Object 



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# File 'lib/brain_love/vm.rb', line 23

def code_dump
  index = 0
  @code.each_byte do |b|
    print "#{index} "
    index += 1
    case b
    when NOOP
      puts "NOOP"
    when INC_DP
      puts "INC_DP"
    when DEC_DP
      puts "DEC_DP"
    when INC_BYTE
      puts "INC_BYTE"
    when DEC_BYTE
      puts "DEC_BYTE"
    when PUTC
      puts "PUTC"
    when GETC
      puts "GETC"
    when JMPFZ
      puts "JMPFZ"
      @jmp = true
    when JMPBNZ
      puts "JMPBNZ"
      @jmp = true
    else
      if @jmp
        @jmp = false
        puts " offset #{b}"
      else
        puts "UNKNOWN BYTECODE"
      end
    end
  end
end

#execute ⇒ Object 



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# File 'lib/brain_love/vm.rb', line 60

def execute
  while @ip < @code.bytesize do
    case @code[@ip].ord
    when NOOP
    when INC_DP
      @dp += 1
    when DEC_DP
      @dp -= 1
    when INC_BYTE
      @data[@dp] = 0 if @data[@dp] == 255
      @data[@dp] += 1
    when DEC_BYTE
      @data[@dp] = 256 if @data[@dp] == 0
      @data[@dp] -= 1
    when PUTC
      @output.putc(@data[@dp].chr)
    when GETC
      @data[@dp] = (@input.getc || 0).ord
    when JMPFZ
      @ip += @code[@ip + 1].ord - 1 if @data[@dp] == 0
    when JMPBNZ
      unless @data[@dp] == 0
        @ip -= @code[@ip + 1].ord
      else
        @ip += 1
      end
    end

    @ip += 1
  end
end