/usr/lib/ruby/2.3.0/rdf/redland/statement.rb is in ruby-librdf 1.0.17.1+dfsg-1.3+b1.
This file is owned by root:root, with mode 0o644.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 | require 'rdf/redland'
module Redland
# Redland Statement (triple class). The main means of manipulating
# statements is by the subject,predicate,and object properties
#
# require 'rdf'
# Statement creation from nodes
# statement1 = Statement.new(node1,node2,node3)
# statement2 = Statement.new(:statement=>statement)
#
# if statement2.resource?
# puts "statement2.subject has uri #{statement2.subject.uri}"
#
class Statement
include Util
# the internal librdf statement
attr_reader :statement
# create a new Statement with subject,predicate,and object
# the subject, predicate, and objects can be of class String or
# Uri.
def initialize(subject=nil,predicate=nil,object=nil,model=nil)
@model = model
if subject.class == Hash
if subject.key?(:from_object)
@statement = Redland.librdf_new_statement_from_statement(subject[:from_object])
@model = subject[:model]
end
else
unless subject
s = nil
else
if (subject.class == Uri)|| (subject.class == String)
subject = Node.new(subject)
end
s = Redland.librdf_new_node_from_node(subject.node)
end
unless predicate
p = nil
else
if (predicate.class == Uri) || (predicate.class == String)
predicate = Node.new(predicate)
end
p = Redland.librdf_new_node_from_node(predicate.node)
end
unless object
o = nil
else
if (object.class == Uri) || (object.class == String)
object = Node.new(object)
end
o = Redland.librdf_new_node_from_node(object.node)
end
@statement = Redland.librdf_new_statement_from_nodes($world.world,s,p,o)
end
raise RedlandError.new("Statement construction failed") if !@statement
ObjectSpace.define_finalizer(self,Statement.create_finalizer(@statement))
end
# You shouldn't use this. Used internally for cleanup.
def Statement.create_finalizer(statement)
proc {|id| Redland::librdf_free_statement(statement) }
end
def wrap_node(rednode)
return Node.new(:from_object=>rednode)
end
private :wrap_node
# return the subject of the statement triple. The subject is of class
# Resource
def subject()
return Resource.new(Redland.librdf_statement_get_subject(self.statement),@model)
end
# return the predicate of the statement triple.
def predicate()
return wrap_node(Redland.librdf_statement_get_predicate(self.statement))
end
# return the object of the statement triple. The return value is either
# a Literal or Resource depending if object returned from the store
# is literal or not
def object()
object_node = Redland.librdf_statement_get_object(self.statement)
return Literal.from_node(object_node) if is_literal?(object_node)
return Resource.new(object_node,@model)
end
# set the subject of the statement
def subject=(value)
if value
Redland.librdf_statement_set_subject(self.statement,
Redland.librdf_new_node_from_node(value.node))
else
Redland.librdf_statement_set_subject(self.statement, nil)
end
end
# set the object of the statement
def object=(value)
if value
Redland.librdf_statement_set_object(self.statement,
Redland.librdf_new_node_from_node(value.node))
else
Redland.librdf_statement_set_object(self.statement, nil)
end
end
# set the predicate of the statement
def predicate=(value)
if value
Redland.librdf_statement_set_predicate(self.statement,
Redland.librdf_new_node_from_node(value.node))
else
Redland.librdf_statement_set_predicate(self.statement, nil)
end
end
# Convert this Statement to a string
def to_s()
unless self.statement
raise RedlandError.new("Statement is invalid")
else
return Redland.librdf_statement_to_string(self.statement)
end
end
# Equivalency. Only works for comparing two Statements
def ==(other)
return (Redland.librdf_statement_equals(self.statement,other.statement) != 0)
end
end
end #module Redland
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