Class: Gecode::Constraints::Set::Relation::EqualityRelationConstraint

Inherits:
ReifiableConstraint show all
Defined in:
lib/gecoder/interface/constraints/set/relation.rb

Overview

Describes a relation constraint which constrains a set variable to be equal to another set variable. Equality may either be expressed as ==, equal or equal_to.

Examples

# +set_1+ must be equal to +set_2+
set_1.must == set_2

# +set_1+ must not be equal to +set_2+
set_1.must_not == set_2

# The same as above but reified with the boolean variable 
# +are_not_equal+.
set_1.must_not.equal(set_2, :reify => are_not_equal)

Instance Method Summary collapse

Methods inherited from ReifiableConstraint

#&, #reification_var, #reification_var=, #|

Methods inherited from Constraint

#initialize

Constructor Details

This class inherits a constructor from Gecode::Constraints::Constraint

Instance Method Details

#post ⇒ Object 



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# File 'lib/gecoder/interface/constraints/set/relation.rb', line 69

def post
  var, rhs, reif_var, negate = @params.values_at(:lhs, :rhs, :reif, 
    :negate)
  if negate
    rel_type = Gecode::Constraints::Util::NEGATED_SET_RELATION_TYPES[:==]
  else
    rel_type = Gecode::Constraints::Util::SET_RELATION_TYPES[:==]
  end
  
  (params = []) << var.bind
  params << rel_type
  params << rhs.bind
  params << reif_var.bind if reif_var.respond_to? :bind
  Gecode::Raw::rel(@model.active_space, *params)
end