Class: SPARQL::Algebra::Operator::Table

Inherits:
SPARQL::Algebra::Operator show all
Includes:
Query
Defined in:
vendor/bundler/ruby/2.5.0/bundler/gems/sparql-b66c70fb77a0/lib/sparql/algebra/operator/table.rb

Overview

The SPARQL Table operator.

This is used to provide inline values. Each row becomes a solution.

Examples:

(table (vars ?book ?title)
  (row (?title "SPARQL Tutorial"))
  (row (?book :book2)))

empty table

(table unit)

See Also:

Constant Summary collapse

NAME =
[:table]

Constants inherited from SPARQL::Algebra::Operator

ARITY, IsURI, URI

Instance Attribute Summary

Attributes included from Query

#solutions

Attributes inherited from SPARQL::Algebra::Operator

#operands

Instance Method Summary collapse

Methods included from Query

#each_solution, #empty?, #failed?, #graph_name=, #matched?, #query_yields_boolean?, #query_yields_solutions?, #query_yields_statements?, #unshift, #variables

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

Instance Method Details

#execute(queryable, options = {}) {|solution| ... } ⇒ RDF::Query::Solutions

Returns solutions for each row

Parameters:

  • queryable (RDF::Queryable)

    the graph or repository to query

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

    any additional keyword options

Yields:

  • (solution)

    each matching solution

Yield Parameters:

Yield Returns:

  • (void)

    ignored

Returns:

See Also:



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# File 'vendor/bundler/ruby/2.5.0/bundler/gems/sparql-b66c70fb77a0/lib/sparql/algebra/operator/table.rb', line 36

def execute(queryable, options = {}, &block)
  @solutions = RDF::Query::Solutions()
  Array(operands[1..-1]).each do |row|
    next unless row.is_a?(Array)
    bindings = row[1..-1].inject({}) do |memo, (var, value)|
      memo[var.to_sym] = value unless value == :undef
      memo
    end
    @solutions << RDF::Query::Solution.new(bindings)
  end
  @solutions.each(&block) if block_given?
  @solutions
end