Class: Gecode::Constraints::Set::Cardinality::SizeExpressionStub

Inherits:
CompositeStub show all
Defined in:
lib/gecoder/interface/constraints/set/cardinality.rb

Overview

Describes a CompositeStub for the cardianlity constraint which constrains the cardianlity (size) of a set.

Example

# The size of +set+ must be within 1..17
set.size.must_be.in 1..17

# The size must equal the integer variable +size+.
set.size.must == size

# The size must not be larger than 17
set.size.must_not > 17

# We reify the above with a boolean variable called +is_not_large+ and 
# select the strength +domain+.
set.size.must_not_be.larger_than(17, :reify => is_not_large, 
  :strength => :domain)

Instance Method Summary collapse

Methods inherited from 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::Set::Cardinality::CompositeStub

Instance Method Details

#constrain_equal(variable, params, constrain) ⇒ Object 



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# File 'lib/gecoder/interface/constraints/set/cardinality.rb', line 65

def constrain_equal(variable, params, constrain)
  lhs = @params[:lhs]
  if constrain
    variable.must_be.in lhs.lower_bound.size..lhs.upper_bound.size
  end
  
  Gecode::Raw::cardinality(@model.active_space, lhs.bind, variable.bind)
end