Class: IntPowerInstruction

Inherits:
Instruction show all
Defined in:
lib/instructions/int/int_power.rb

Overview

pops the top 2 items of the :int stack; pushes a ValuePoint with value x**y, where x is the second stack item, y the top one

note: the top item is the exponent, the second item is the base

note: will push an :error ValuePoint instead of an :int if asked to take a negative root of 0

needs: 2 :int

pushes: 1 :int

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/int/int_power.rb', line 25

def cleanup
  pushes :int, @result
end

#derive ⇒ Object

Raises:



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# File 'lib/instructions/int/int_power.rb', line 21

def derive
  raise NaNResultError,"#{self.class} attempted negative root of 0" if @arg1 == 0 && @arg2 < 0
  @result = ValuePoint.new("int", (@arg1**@arg2).to_i)
end

#preconditions? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/instructions/int/int_power.rb', line 14

def preconditions?
  needs :int, 2
end

#setup ⇒ Object 



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# File 'lib/instructions/int/int_power.rb', line 17

def setup
  @arg2 = @context.pop_value(:int)
  @arg1 = @context.pop_value(:int)
end