Class: SPARQL::Algebra::Operator::Delete

Inherits:
Unary show all
Includes:
Update
Defined in:
vendor/bundler/ruby/2.5.0/bundler/gems/sparql-7b34b4cf091a/lib/sparql/algebra/operator/delete.rb

Overview

The SPARQL UPDATE delete operator.

The DELETE operation is a form of the DELETE/INSERT operation having no INSERT section

Examples:

(delete ((triple ?s ?p ?o))))

See Also:

Constant Summary collapse

NAME =
[:delete]

Constants inherited from Unary

Unary::ARITY

Constants inherited from SPARQL::Algebra::Operator

ARITY, IsURI, URI

Instance Attribute Summary

Attributes inherited from SPARQL::Algebra::Operator

#operands

Instance Method Summary collapse

Methods included from Update

#graph_name=, #unshift, #variables

Methods inherited from Unary

#initialize

Methods inherited from SPARQL::Algebra::Operator

#aggregate?, arity, #base_uri, base_uri, base_uri=, #boolean, #constant?, #each_descendant, #eql?, #evaluatable?, evaluate, #executable?, #first_ancestor, for, #initialize, #inspect, #ndvars, #node?, #operand, #optimize, #parent, #parent=, prefixes, #prefixes, prefixes=, #rewrite, #to_binary, #to_sxp, #to_sxp_bin, #validate!, #variable?, #vars

Methods included from Expression

cast, #constant?, #evaluate, extension, extensions, for, #invalid?, new, #node?, open, #optimize, parse, register_extension, #to_sxp_bin, #valid?, #validate!, #variable?

Constructor Details

This class inherits a constructor from SPARQL::Algebra::Operator::Unary

Instance Method Details

#execute(queryable, solution, options = {}) ⇒ RDF::Queryable

Executes this upate on the given writable graph or repository.

Parameters:

  • queryable (RDF::Queryable)

    the graph or repository to write

  • solution (RDF::Query::Solution)

    Solution to map to patterns for this operation

  • options (Hash{Symbol => Object}) (defaults to: {})

    any additional keyword options

Options Hash (options):

  • debug (Boolean)

    Query execution debugging

Returns:

Raises:

  • (IOError)

    If from does not exist, unless the silent operator is present

See Also:



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# File 'vendor/bundler/ruby/2.5.0/bundler/gems/sparql-7b34b4cf091a/lib/sparql/algebra/operator/delete.rb', line 34

def execute(queryable, solution, options = {})
  debug(options) {"Delete: #{solution} against #{operands.to_sse}"}
  # Operands are an array of patterns and Queries (when named).
  # Create a new query made up all patterns
  patterns = operand.inject([]) do |memo, op|
    if op.respond_to?(:statements)
      memo += op.statements.to_a
    else
      memo << op
    end
    memo
  end
  patterns.each do |pattern|
    pattern = pattern.dup.bind(solution)
    debug(options) {"Delete statement #{statement.to_sse}"}
    queryable.delete(RDF::Statement.from(pattern)) if pattern.bound? || pattern.constant?
  end
  queryable
end