Class: ShEx::Algebra::TripleConstraint

Inherits:
Operator
  • Object
show all
Includes:
TripleExpression
Defined in:
lib/shex/algebra/triple_constraint.rb

Constant Summary collapse

NAME = 
:tripleConstraint

Constants inherited from Operator

Operator::ARITY

Instance Attribute Summary

Attributes inherited from Operator

#id, #logger, #operands, #options, #schema

Class Method Summary collapse

Instance Method Summary collapse

Methods included from TripleExpression

#maximum, #minimum, #triple_expression?

Methods inherited from Operator

#base_uri, #closed?, #each_descendant, #eql?, #expression, #expressions, #focus, #focus=, #initialize, #inspect, #iri, iri, #json_type, #matched, #matched=, #message, #message=, #not_matched, #not_satisfied, #operand, #parent, #parent=, #satisfied, #satisfied=, #satisfy, #semact?, #semantic_actions, #serialize_value, #status, #structure_error, #to_h, #to_json, #to_sxp, #to_sxp_bin, #triple_expression?, #unmatched, #unmatched=, #unsatisfied, #unsatisfied=, value, #value

Constructor Details

This class inherits a constructor from ShEx::Algebra::Operator

Class Method Details

.from_shexj(operator, options = {}) ⇒ Operator

Creates an operator instance from a parsed ShExJ representation

Returns:

Raises:

  • (ArgumentError) 


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# File 'lib/shex/algebra/triple_constraint.rb', line 11

def self.from_shexj(operator, options = {})
  raise ArgumentError unless operator.is_a?(Hash) && operator['type'] == 'TripleConstraint'
  raise ArgumentError unless operator.has_key?('predicate')
  super
end

Instance Method Details

#inverse? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/shex/algebra/triple_constraint.rb', line 112

def inverse?
  operands.include?(:inverse)
end

#matches(arcs_in, arcs_out, depth: 0) ⇒ TripleExpression

In this case, we accept an array of statements, and match based on cardinality.

Parameters:

  • arcs_in (Array<RDF::Statement>)
  • arcs_out (Array<RDF::Statement>)

Returns:

Raises:

  • (ShEx::NotMatched) —

    with ‘expression` accessor to access `matched` and `unmatched` statements along with `satisfied` and `unsatisfied` operations.



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# File 'lib/shex/algebra/triple_constraint.rb', line 23

def matches(arcs_in, arcs_out, depth: 0)
  status "predicate #{predicate}", depth: depth
  results, unmatched, satisfied, unsatisfied = [], [], [], []
  num_iters, max = 0, maximum

  statements = inverse? ? arcs_in : arcs_out
  statements.select {|st| st.predicate == predicate}.each do |statement|
    break if num_iters == max # matched enough

    focus = inverse? ? statement.subject : statement.object

    begin
      matched_shape = if expression.is_a?(RDF::Resource)
        schema.enter_shape(expression, focus) do |shape|
          if shape
            shape.satisfies?(focus, depth: depth + 1)
          else
            status "Satisfy as #{expression} was re-entered for #{focus}", depth: depth
            nil
          end
        end
      elsif expression
        expression.satisfies?(focus, depth: depth + 1)
      end
      status "matched #{statement.to_sxp}", depth: depth
      if matched_shape
        matched_shape.matched = [statement]
        statement = statement.dup.extend(ReferencedStatement)
        statement.referenced = matched_shape
        satisfied << matched_shape
      end
      results << statement
      num_iters += 1
    rescue ShEx::NotSatisfied => e
      status "not satisfied: #{e.message}", depth: depth
      unsatisfied << e.expression
      statement = statement.dup.extend(ReferencedStatement)
      statement.referenced = expression
      unmatched << statement
    end
  end

  # Max violations handled in Shape
  if results.length < minimum
    raise ShEx::NotMatched, "Minimum Cardinality Violation: #{results.length} < #{minimum}"
  end

  # Last, evaluate semantic acts
  semantic_actions.each do |op|
    op.satisfies?(results, matched: results, depth: depth + 1)
  end unless results.empty?

  satisfy matched:   results,   unmatched:   unmatched,
          satisfied: satisfied, unsatisfied: unsatisfied, depth: depth
rescue ShEx::NotMatched, ShEx::NotSatisfied => e
  not_matched e.message,
              matched:   results,   unmatched:   unmatched,
              satisfied: satisfied, unsatisfied: unsatisfied, depth: depth
end

#predicate ⇒ Object 



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# File 'lib/shex/algebra/triple_constraint.rb', line 83

def predicate
  @predicate ||= operands.detect {|o| o.is_a?(Array) && o.first == :predicate}.last
end

#triple_constraints ⇒ Array<TripleConstraints>

Included TripleConstraints

Returns:

  • (Array<TripleConstraints>) 


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# File 'lib/shex/algebra/triple_constraint.rb', line 108

def triple_constraints
  [self]
end

#validate! ⇒ Operator

expression must be a ShapeExpression

Returns:

Raises:



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# File 'lib/shex/algebra/triple_constraint.rb', line 92

def validate!
  case expression
  when nil, ShapeExpression
  when RDF::Resource
    ref = schema.find(expression)
    ref.is_a?(ShapeExpression) ||
    structure_error("#{json_type} must reference a ShapeExpression: #{ref}")
  else
    structure_error("#{json_type} must reference a ShapeExpression: #{ref}")
  end
  super
end