More moves towards Triple Terms vs Quoted Triples.

Author: gkellogg

README.md

@@ -280,19 +280,24 @@ Internally, an `RDF::Statement` is treated as another resource, along with `RDF:
 
 **Note: This feature is subject to change or elimination as the standards process progresses.**
 
-### Serializing a Graph containing quoted triples
+### Serializing a Graph containing triple terms
 
     require 'rdf/ntriples'
     statement = RDF::Statement(RDF::URI('bob'), RDF::Vocab::FOAF.age, RDF::Literal(23))
-    graph = RDF::Graph.new << [statement, RDF::URI("ex:certainty"), RDF::Literal(0.9)]
+    reifier = RDF::Node.new
+    graph = RDF::Graph.new do |g|
+      g << [reifier, RDF.reifies, statement]
+      g << [reifier, RDF::URI("ex:certainty"), RDF::Literal(0.9)]
+    end
     graph.dump(:ntriples, validate: false)
-    # => '<<<bob> <http://xmlns.com/foaf/0.1/age> "23"^^<http://www.w3.org/2001/XMLSchema#integer>>> <ex:certainty> "0.9"^^<http://www.w3.org/2001/XMLSchema#double> .'
+    # ==> '_:bn <http://www.w3.org/1999/02/22-rdf-syntax-ns#reifies> <<(<bob> <http://xmlns.com/foaf/0.1/age> "23"^^<http://www.w3.org/2001/XMLSchema#integer>)>> .
+           _:bn <ex:certainty> "0.9"^^<http://www.w3.org/2001/XMLSchema#double> .'
 
-### Reading a Graph containing quoted triples
+### Reading a Graph containing triple terms
 
 By default, the N-Triples reader will reject a document containing a subject resource.
 
-    nt = '<<<bob> <http://xmlns.com/foaf/0.1/age> "23"^^<http://www.w3.org/2001/XMLSchema#integer>>> <ex:certainty> "0.9"^^<http://www.w3.org/2001/XMLSchema#double> .'
+    nt = '<<(<bob> <http://xmlns.com/foaf/0.1/age> "23"^^<http://www.w3.org/2001/XMLSchema#integer>)>> <ex:certainty> "0.9"^^<http://www.w3.org/2001/XMLSchema#double> .'
     graph = RDF::Graph.new do |graph|
       RDF::NTriples::Reader.new(nt) {|reader| graph << reader}
     end

lib/rdf/model/statement.rb

@@ -476,7 +476,7 @@ def to_h(subject_key = :subject, predicate_key = :predicate, object_key = :objec
     def to_s
       (graph_name ? to_quad : to_triple).map do |term|
         if term.is_a?(Statement)
-          "<<#{term.to_s[0..-3]}>>"
+          "<<(#{term.to_s[0..-3]})>>"
         elsif term.respond_to?(:to_base)
           term.to_base
         else

lib/rdf/ntriples/reader.rb

@@ -30,7 +30,7 @@ module RDF::NTriples
   #
   # ** RDF=star
   #
-  # Supports statements as resources using `<<s p o>>`.
+  # Supports statements as resources using `<<(s p o)>>`.
   #
   # @see http://www.w3.org/TR/rdf-testcases/#ntriples
   # @see http://www.w3.org/TR/n-triples/
@@ -73,8 +73,8 @@ class Reader < RDF::Reader
     TT_START              = /^<<\(/.freeze
     TT_END                = /^\s*\)>>/.freeze
 
-    QT_START              = /^<</.freeze
-    QT_END                = /^\s*>>/.freeze
+    QT_START              = /^<</.freeze      # DEPRECATED
+    QT_END                = /^\s*>>/.freeze   # DEPRECATED
 
     # @see http://www.w3.org/TR/rdf-testcases/#ntrip_grammar
     COMMENT               = /^#\s*(.*)$/.freeze