Class: Gecode::Constraints::IntEnum::Arithmetic::MaxExpressionStub

Inherits:
Gecode::Constraints::Int::CompositeStub show all
Defined in:
lib/gecoder/interface/constraints/int_enum/arithmetic.rb

Overview

Describes a CompositeStub for the max constraint, which constrains the maximum value of the integer variables in an enumeration.

Example

# The maximum must be positive.
int_enum.max.must > 0

# The maximum must equal a integer variable +max+.
int_enum.max.must == max

# The maximum must not be negative. The constraint is reified with the 
# boolean variable +is_negative+ and strength +domain+ is selected.
int_enum.max.must_not_be.less_than(0, :reify => is_negative, 
  :strength => :domain)

Instance Method Summary collapse

Methods inherited from Gecode::Constraints::Int::CompositeStub

#initialize

Methods inherited from CompositeStub

#initialize

Methods included from LeftHandSideMethods

#must, #must_not

Methods inherited from ExpressionStub

#initialize

Constructor Details

This class inherits a constructor from Gecode::Constraints::Int::CompositeStub

Instance Method Details

#constrain_equal(variable, params, constrain) ⇒ Object 



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# File 'lib/gecoder/interface/constraints/int_enum/arithmetic.rb', line 35

def constrain_equal(variable, params, constrain)
  enum, strength = @params.values_at(:lhs, :strength)
  if constrain
    variable.must_be.in enum.domain_range
  end
  
  Gecode::Raw::max(@model.active_space, enum.to_int_var_array, 
    variable.bind, strength)
end