Class: Gecode::Int::Arithmetic::IntSquareRootOperand

Inherits:
ShortCircuitEqualityOperand show all
Defined in:
lib/gecoder/interface/constraints/int/arithmetic.rb

Overview

:nodoc:

Instance Attribute Summary

Attributes inherited from ShortCircuitEqualityOperand

#model

Instance Method Summary collapse

Methods inherited from ShortCircuitEqualityOperand

#construct_receiver, #to_int_var

Methods included from IntOperand

#*, #+, #-, #abs, #method_missing, #pre_arith_mult, #square_root, #squared

Methods included from Operand

#model, #must, #must_not

Constructor Details

#initialize(model, int_op) ⇒ IntSquareRootOperand

Returns a new instance of IntSquareRootOperand.



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# File 'lib/gecoder/interface/constraints/int/arithmetic.rb', line 119

def initialize(model, int_op)
  super model
  @int = int_op
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method in the class Gecode::Int::IntOperand

Instance Method Details

#constrain_equal(int_operand, constrain, propagation_options) ⇒ Object 



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# File 'lib/gecoder/interface/constraints/int/arithmetic.rb', line 124

def constrain_equal(int_operand, constrain, propagation_options)
  int_op = @int.to_int_var
  if constrain
    max = int_op.max
    if max < 0
      # The left hand side does not have a real valued square root.
      upper_bound = 0
    else
      upper_bound = Math.sqrt(max).floor;
    end
    
    min = int_op.min
    if min < 0
      lower_bound = 0
    else
      lower_bound = Math.sqrt(min).floor;
    end
    
    int_operand.must_be.in lower_bound..upper_bound
  end

  Gecode::Raw::sqrt(@model.active_space, int_op.to_int_var.bind, 
    int_operand.to_int_var.bind, *propagation_options)
end