Class: SPARQL::Algebra::Operator::SHA256

Inherits:

Unary

• Object
• SPARQL::Algebra::Operator
• Unary
• SPARQL::Algebra::Operator::SHA256

Includes:

Evaluatable

Defined in:

vendor/bundler/ruby/2.5.0/bundler/gems/sparql-b66c70fb77a0/lib/sparql/algebra/operator/sha256.rb

Overview

The SPARQL logical sha256 operator.

Returns the SHA256 checksum, as a hex digit string, calculated on the UTF-8 representation of the simple literal or lexical form of the xsd:string. Hex digits SHOULD be in lower case.

Examples:

(prefix ((: <http://example.org/>))
  (project (?hash)
    (extend ((?hash (sha256 ?l)))
      (bgp (triple :s1 :str ?l)))))

See Also:

• http://www.w3.org/TR/sparql11-query/#func-sha256

Constant Summary

NAME =

:sha256

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

• #apply(operand) ⇒ RDF::Literal

  Returns the SHA256 checksum, as a hex digit string, calculated on the UTF-8 representation of the simple literal or lexical form of the xsd:string.

Methods included from Evaluatable

#evaluate, #memoize, #replace_aggregate!, #replace_vars!

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

#apply(operand) ⇒ RDF::Literal

Returns the SHA256 checksum, as a hex digit string, calculated on the UTF-8 representation of the simple literal or lexical form of the xsd:string. Hex digits should be in lower case.

Parameters:

• operand (RDF::Literal) —

  the operand

Returns:

• (RDF::Literal)

Raises:

• (TypeError) —

  if the operand is not a simple literal

# File 'vendor/bundler/ruby/2.5.0/bundler/gems/sparql-b66c70fb77a0/lib/sparql/algebra/operator/sha256.rb', line 29

def apply(operand)
  raise TypeError, "expected an RDF::Literal, but got #{operand.inspect}" unless operand.literal?
  raise TypeError, "expected simple literal or xsd:string, but got #{operand.inspect}" unless (operand.datatype || RDF::XSD.string) == RDF::XSD.string
  RDF::Literal(Digest::SHA256.new.hexdigest(operand.to_s))
end