Class: Base::VM

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

Constant Summary collapse

Error = 
Class.new(StandardError)
MAX_MEMORY = 
1048576
COMMANDS = 
%w(debug push discard duplicate write read add subtract multiply divide jump bltz bgtz betz bnetz out halt)

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(program, debug: false) ⇒ VM

Returns a new instance of VM.



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# File 'lib/base/vm.rb', line 11

def initialize(program, debug: false)
  @ip = program.start_location
  @memory = program.memory
  @debug = debug
  @stack = Stack.new
end

Instance Attribute Details

#ip ⇒ Object (readonly)

Returns the value of attribute ip.



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# File 'lib/base/vm.rb', line 7

def ip
  @ip
end

#memory ⇒ Object (readonly)

Returns the value of attribute memory.



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# File 'lib/base/vm.rb', line 7

def memory
  @memory
end

#stack ⇒ Object (readonly)

Returns the value of attribute stack.



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# File 'lib/base/vm.rb', line 7

def stack
  @stack
end

Instance Method Details

#run ⇒ Object

Raises:



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# File 'lib/base/vm.rb', line 18

def run
  loop do
    raise Error, "IP reached end of memory" if memory[ip].nil?

    @debug = Debugger.new(self).debug if @debug

    begin
      result = execute
      break if result == :halt
    rescue Error => e
      $stderr.puts("error: #{e.message}")
      @debug = true
    end
  end

  raise Error, "warning: stack not empty at program termination, #{stack.inner}" unless @stack.empty?
end