Class: Gecode::Constraints::IntEnum::Sort::SortConstraintWithOptions

Inherits:
Constraint
  • Object
show all
Defined in:
lib/gecoder/interface/constraints/int_enum/sort.rb

Overview

Describes a sort constraint which constrains a target enumeration of integer variables to be the sorted version of another set of integer variables. Optionally a third enumeration may be used to define the order in which the the variables should be sorted.

Neither negation nor reification is supported.

Example

# Constrains +sorted_numbers+ to be a sorted version of +numbers+. 
numbers.must_be.sorted(:as => sorted_numbers)

# Constrains +sorted_numbers+ to be +numbers+ sorted in the order 
# described by the integer variable enumeration +order+. 
numbers.must_be.sorted(:as => sorted_numbers, :order => order)

Instance Method Summary collapse

Methods inherited from Constraint

#initialize

Constructor Details

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

Instance Method Details

#post ⇒ Object 



72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
 
# File 'lib/gecoder/interface/constraints/int_enum/sort.rb', line 72

def post
  if @params[:target].nil?
    # We must have a target.
    lhs = @params[:lhs]
    @params[:target] = @model.int_var_array(lhs.size, lhs.domain_range)
  end
  
  # Prepare the parameters.
  params = @params.values_at(:lhs, :target, :order).map do |param| 
    if param.respond_to? :to_int_var_array
      param.to_int_var_array
    else
      param
    end
  end.delete_if{ |param| param.nil? }
  params.concat propagation_options
  
  # Post the constraint.
  Gecode::Raw::sorted(@model.active_space, *params)
end