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

Inherits:

Unary

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

Includes:

Evaluatable

Defined in:

vendor/bundler/ruby/3.3.0/bundler/gems/sparql-796d3be4aa08/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.

[121] BuiltInCall ::= ... | 'SHA256' '(' Expression ')'

Examples:

SPARQL Grammar

PREFIX : <http://example.org/>
SELECT (SHA256(?l) AS ?hash) WHERE {
 :s1 :str ?l
}

SSE

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

See Also:

• https://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

Constants included from Expression

Expression::PATTERN_PARENTS

Constants included from RDF::Util::Logger

RDF::Util::Logger::IOWrapper

Instance Attribute Summary

Attributes inherited from SPARQL::Algebra::Operator

#operands

Instance Method Summary

• #apply(operand, **options) ⇒ 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.

• #to_sparql(**options) ⇒ String

  Returns a partial SPARQL grammar for this operator.

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=, #bind, #boolean, #constant?, #deep_dup, #each_descendant, #eql?, #evaluatable?, evaluate, #executable?, #first_ancestor, for, #formulae, #initialize, #inspect, #mergable?, #ndvars, #node?, #operand, #optimize, #optimize!, #parent, #parent=, #prefixes, prefixes, prefixes=, #rewrite, #to_binary, to_sparql, #to_sxp, #to_sxp_bin, #validate!, #variable?, #variables, #vars

Methods included from Expression

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

Methods included from RDF::Util::Logger

#log_debug, #log_depth, #log_error, #log_fatal, #log_info, #log_recover, #log_recovering?, #log_statistics, #log_warn, #logger

Constructor Details

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

Instance Method Details

#apply(operand, **options) ⇒ 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/3.3.0/bundler/gems/sparql-796d3be4aa08/lib/sparql/algebra/operator/sha256.rb', line 37

def apply(operand, **options)
  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

#to_sparql(**options) ⇒ String

Returns a partial SPARQL grammar for this operator.

Returns:

• (String)

# File 'vendor/bundler/ruby/3.3.0/bundler/gems/sparql-796d3be4aa08/lib/sparql/algebra/operator/sha256.rb', line 48

def to_sparql(**options)
  "SHA256(" + operands.to_sparql(**options) + ")"
end