Class: CodeDoCountInstruction

Inherits:
Instruction show all
Defined in:
lib/instructions/code/code_do_count.rb

Overview

Again, the original description of this instruction appears to be confusing “CODE.DO*RANGE” with “EXEC.DO*RANGE”; I’ve made the adjustment to the code so that the behavior is as described, not the implementation.

Instance Attribute Summary

Attributes inherited from Instruction

#context

Instance Method Summary collapse

Methods inherited from Instruction

all_instructions, #go, inherited, #initialize, #needs, #pushes, to_nudgecode

Constructor Details

This class inherits a constructor from Instruction

Instance Method Details

#cleanup ⇒ Object 



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# File 'lib/instructions/code/code_do_count.rb', line 22

def cleanup
  recursor = CodeblockPoint.new([ValuePoint.new("int",0), @one_less,
    InstructionPoint.new("exec_do_range"),@codeblock])
  pushes :exec, recursor
end

#derive ⇒ Object 



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# File 'lib/instructions/code/code_do_count.rb', line 17

def derive
  @codeblock = NudgeProgram.new(@code).linked_code
  @one_less = ValuePoint.new("int",@destination.value-1)
end

#preconditions? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/instructions/code/code_do_count.rb', line 4

def preconditions?
  needs ExecDoRangeInstruction
  needs :code, 1
  needs :int, 1
end

#setup ⇒ Object

Raises:



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# File 'lib/instructions/code/code_do_count.rb', line 10

def setup
  @destination = @context.pop(:int)
  @code = @context.pop_value(:code)
  raise InstructionMethodError,
    "#{self.class.to_nudgecode} needs a positive argument" if @destination.value < 1
end