Initial import of Treetop-based N3 parser

lib/rena/n3_grammer.treetop

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+grammar N3Grammer
+	rule document
+		statements
+	end
+
+	rule statements
+		(space / (statement / directive) space* ('.' space*)? )*
+	end
+
+	rule statement
+		subject space+ property_list
+	end
+
+	rule subject
+		node
+	end
+
+	rule verb
+		">-" prop "->"      # has xxx of 
+		/ "<-" prop "<-"    # is xxx of 
+		# / # / operator     # has operator:xxx of??? NOT IMPLMENTED
+		/ prop              # has xxx of -- shorthand
+		# / "has" prop        # has xxx of
+		# / "is" prop "of"    # is xxx of
+		/ "a"               # has rdf:type of
+		# / "="               # has daml:equivaent of
+	end
+
+	rule prop
+		node
+	end
+
+	rule node
+		uri_ref2 / anonnode / 'this'
+	end
+
+	rule anonnode
+		"[" space* property_list space* "]"  # something which ...
+		/ "{" statementlist "}"  # the statementlist itself as a resource
+		/ "(" nodelist ")" {
+			def anonnode; true; end
+		}
+	end
+
+	rule property_list
+		verb space+ object_list space* ";" space+ property_list
+		/ verb space+ object_list
+		/ ":-" anonnode  #to allow two anonymous forms to be given eg [ a :Truth; :- { :sky :color :blue } ] )
+		/ ":-" anonnode ";" property_list
+		/ '.'
+	end
+
+	rule object_list
+		object "," space* object_list / object
+	end
+
+	rule directive
+		'@prefix' space+ nprefix:nprefix? ':' space+ uri_ref2:uri_ref2 {
+			def directive; true; end
+		}
+	end
+
+	rule uri_ref2
+		qname / "<" uri:URI_Reference ">"
+	end
+
+	rule qname
+		nprefix ":" localname / ':' localname
+	end
+
+	rule object
+		subject 
+		/ string1 # " constant-value-with-escaping "
+		/ string2 # """ constant value with escaping including single or double occurences of quotes and/or newlines """
+	end
+
+	rule localname
+		fragid
+	end
+
+	rule URI_Reference
+		[^{}<>]*
+	end
+
+	rule nprefix
+		((alpha / "_") alphanumeric*)
+	end
+
+	rule fragid
+		alpha alphanumeric*
+	end
+
+	rule alpha
+		[a-zA-Z]
+	end
+
+	rule alphanumeric
+		alpha / [0-9] / "_"
+	end
+
+	rule space
+		[ \t\n\r]+ / comment
+	end
+
+	rule comment
+	  '#' (![\n\r] .)*
+	end
+
+	rule string1
+		'"' string1_char+ '"'
+	end
+
+	rule string1_char
+		!["] .
+	end
+
+	rule string2
+		'"""' string2_char* '"""'
+	end
+
+	rule string2_char
+		!'"""' . # something like this; need to think about it some more	
+	end
+
+end

lib/rena/n3parser.rb

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+require 'rena/graph'
+require 'treetop'
+
+Treetop.load(File.join(File.dirname(__FILE__), "n3_grammer"))
+
+class N3Parser
+  attr_accessor :graph
+
+  def initialize(n3_str, uri=nil)
+    @uri = Addressable::URI.parse(uri) unless uri.nil?
+    parser = N3GrammerParser.new
+    document = parser.parse(n3_str)
+    if document
+      @graph = Graph.new
+      process_directives(document)
+      process_statements(document)
+    else
+      parser.terminal_failures.each do |tf|
+        puts "Expected #{tf.expected_string.inspect} (#{tf.index})- '#{string[tf.index,10].inspect}'"
+      end
+    end
+  end
+
+  protected
+
+  def process_directives(document)
+    directives = document.elements.find_all { |e| e.elements.first.respond_to? :directive }
+    directives.map! { |d| d.elements.first }
+    directives.each { |d| namespace(d.uri_ref2.uri.text_value, d.nprefix.text_value) }
+  end
+
+  def namespace(uri, short)
+    short = '__local__' if short == ''
+    @graph.namespace(uri, short)
+  end
+
+  def process_statements(document)
+    subjects = document.elements.find_all { |e| e.elements.first.respond_to? :subject }
+    subjects.map! { |s| s.elements.first }
+    subjects.each do |s|
+      subject = process_node(s.subject)
+      properties = process_properties(s.property_list)
+      properties.each do |p|      
+        predicate = process_verb(p.verb)
+        objects = process_objects(p.object_list)
+        objects.each { |object| triple(subject, predicate, object) }
+      end
+    end
+  end
+
+  def triple(subject, predicate, object)
+    @graph.add_triple(subject, predicate, object)
+  end
+
+  def process_anonnode(anonnode)
+    bnode = BNode.new
+    properties = process_properties(anonnode.property_list)
+    properties.each do |p|      
+      predicate = process_node(p.verb)
+      objects = process_objects(p.object_list)
+      objects.each { |object| triple(bnode, predicate, object) }
+    end
+    bnode
+  end
+
+  def process_verb(verb)
+    return URIRef.new('http://www.w3.org/1999/02/22-rdf-syntax-ns#type') if (verb.text_value=='a')
+    return process_node(verb)
+  end
+
+  def process_node(node)
+    if (node.respond_to? :uri)
+      URIRef.new(node.uri.text_value)
+    else      
+      prefix = (node.respond_to? :nprefix) ? node.nprefix.text_value : nil
+      localname = node.localname.text_value
+      build_uri(prefix, localname)
+    end
+  end
+
+  def process_properties(properties)
+    result = []
+    result << properties if (properties.respond_to? :verb)
+    result << process_properties(properties.property_list) if (properties.respond_to? :property_list)
+    result.flatten
+  end
+
+  def process_objects(objects)
+    result = []
+    if (objects.respond_to? :object)
+      result << process_object(objects.object)
+    else
+      result << process_object(objects)
+    end
+    result << process_objects(objects.object_list) if (objects.respond_to? :object_list)
+    result.flatten
+  end
+
+  def process_object(object)
+    if (object.respond_to? :localname or object.respond_to? :uri)
+      process_node(object)
+    elsif (object.respond_to? :property_list)
+      process_anonnode(object)
+    else
+      Literal.new(object.elements[1].text_value)
+    end
+  end
+
+    # pp objects.object
+    # if (objects.respond_to? :object and objects.object.respond_to? :anonnode)
+    #   pp 'foo'
+    # elsif (objects.respond_to? :object and objects.respond_to? :object_list)
+    #   result << process_node(objects.object)
+    #   result << process_objects(objects.object_list)
+    # elsif (objects.respond_to? :localname)
+    #   result << process_node(objects)
+    # elsif (objects.respond_to? :uri)
+    #   result << URIRef.new(objects.uri.text_value)
+    # else
+    #   result << Literal.new(objects.elements[1].text_value)
+    # end
+  #   result.flatten
+  # end
+
+  def build_uri(prefix, localname)
+    prefix = '__local__' if prefix.nil?
+    if (prefix=='_')
+      BNode.new(localname)
+    else
+      @graph.nsbinding[prefix].send(localname)
+    end
+  end
+
+
+end
+
+# # string = %[
+# #   <rdf:RDF xmlns="http://example.org/#"
+# #       xmlns:log="http://www.w3.org/2000/10/swap/log#"
+# #       xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
+# # 
+# #       <rdf:Description rdf:about="http://example.org/#Subject">
+# #           <predicate rdf:resource="http://example.org/#ObjectP"/>
+# #       </rdf:Description>
+# #   </rdf:RDF>
+# # ]
+# # parser = RdfXmlParser.new(string)
+# # puts parser.graph.to_ntriples
+# 
+# [ 'simple-01.n3', 
+#   'simple-02.n3',
+#   'simple-03.n3',
+#   'simple-04.n3',
+#   'simple-05.n3',
+#   'simple-06.n3',
+#   'simple-07.n3',
+#   'on_now-01.n3',
+#  ].each do |f|
+#   string = File.read("test/n3p_tests/#{f}")
+#   parser = N3Parser.new(string)
+#   puts f
+#   puts parser.graph.to_ntriples
+# end

test/n3_tests/misc/on_now-01.n3

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+@prefix dc: <http://purl.org/dc/elements/1.1/>.
+@prefix po: <http://purl.org/ontology/po/>.
+@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>.
+_:broadcast
+ a po:Broadcast;
+ po:schedule_date """2008-06-24T12:00:00Z""";
+ po:broadcast_of _:version;
+ po:broadcast_on <http://www.bbc.co.uk/programmes/service/6music>;
+.
+_:version
+ a po:Version;
+.
+<http://www.bbc.co.uk/programmes/b0072l93>
+ dc:title """Nemone""";
+ a po:Brand;
+.
+<http://www.bbc.co.uk/programmes/b00c735d>
+ a po:Episode;
+ po:episode <http://www.bbc.co.uk/programmes/b0072l93>;
+ po:version _:version;
+ po:long_synopsis """Actor and comedian Rhys Darby chats to Nemone.""";
+ dc:title """Nemone""";
+ po:synopsis """Actor and comedian Rhys Darby chats to Nemone.""";
+.
+<http://www.bbc.co.uk/programmes/service/6music>
+ a po:Service;
+ dc:title """BBC 6 Music""";
+.

test/n3_tests/misc/on_now-01.nt

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+_:broadcast <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://purl.org/ontology/po/Broadcast> .
+_:broadcast <http://purl.org/ontology/po/schedule_date> "2008-06-24T12:00:00Z" .
+_:broadcast <http://purl.org/ontology/po/broadcast_of> _:version .
+_:broadcast <http://purl.org/ontology/po/broadcast_on> <http://www.bbc.co.uk/programmes/service/6music> .
+_:version <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://purl.org/ontology/po/Version> .
+<http://www.bbc.co.uk/programmes/b0072l93> <http://purl.org/dc/elements/1.1/title> "Nemone" .
+<http://www.bbc.co.uk/programmes/b0072l93> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://purl.org/ontology/po/Brand> .
+<http://www.bbc.co.uk/programmes/b00c735d> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://purl.org/ontology/po/Episode> .
+<http://www.bbc.co.uk/programmes/b00c735d> <http://purl.org/ontology/po/episode> <http://www.bbc.co.uk/programmes/b0072l93> .
+<http://www.bbc.co.uk/programmes/b00c735d> <http://purl.org/ontology/po/version> _:version .
+<http://www.bbc.co.uk/programmes/b00c735d> <http://purl.org/ontology/po/long_synopsis> "Actor and comedian Rhys Darby chats to Nemone." .
+<http://www.bbc.co.uk/programmes/b00c735d> <http://purl.org/dc/elements/1.1/title> "Nemone" .
+<http://www.bbc.co.uk/programmes/b00c735d> <http://purl.org/ontology/po/synopsis> "Actor and comedian Rhys Darby chats to Nemone." .
+<http://www.bbc.co.uk/programmes/service/6music> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://purl.org/ontology/po/Service> .
+<http://www.bbc.co.uk/programmes/service/6music> <http://purl.org/dc/elements/1.1/title> "BBC 6 Music" .

test/n3_tests/n3p/simple-01.n3

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+# simple-01.n3 - Empty file

test/n3_tests/n3p/simple-02.n3

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+# simple-02.n3 - Prefix and Keywords
+
+@prefix : <#> .
+@prefix foaf: <http://xmlns.com/foaf/0.1/> .

test/n3_tests/n3p/simple-03.n3

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+# simple-03.n3 - Simple triple
+
+@prefix foaf: <http://xmlns.com/foaf/0.1/> .
+
+_:Sean foaf:name "Sean B. Palmer" .

test/n3_tests/n3p/simple-03.nt

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+_:Sean <http://xmlns.com/foaf/0.1/name> "Sean B. Palmer" .

test/n3_tests/n3p/simple-04.n3

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+# simple-04.n3 - Multiple objects
+
+@prefix : <http://example.org/#> .
+
+:Subject :predicate :ObjectP, :ObjectQ, 
+                    :ObjectR .

test/n3_tests/n3p/simple-04.nt

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+<http://example.org/#Subject> <http://example.org/#predicate> <http://example.org/#ObjectP> .
+<http://example.org/#Subject> <http://example.org/#predicate> <http://example.org/#ObjectQ> .
+<http://example.org/#Subject> <http://example.org/#predicate> <http://example.org/#ObjectR> .

test/n3_tests/n3p/simple-05.n3

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+# simple-05.n3 - Popairs
+
+@prefix : <#> .
+@prefix foaf: <http://xmlns.com/foaf/0.1/> .
+
+_:Sean foaf:name "Sean B. Palmer"; 
+       foaf:homepage <http://inamidst.com/sbp/> .

test/n3_tests/n3p/simple-05.nt

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+_:Sean <http://xmlns.com/foaf/0.1/name> "Sean B. Palmer" .
+_:Sean <http://xmlns.com/foaf/0.1/homepage> <http://inamidst.com/sbp/> .

test/n3_tests/n3p/simple-06.n3

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+# simple-06.n3 - Popairs and multiple objects
+
+@prefix : <http://example.org/#> .
+
+:Subject :predicateOne :ObjectA, :ObjectB; 
+         :predicateTwo :ObjectC, :ObjectD .

test/n3_tests/n3p/simple-06.nt

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+<http://example.org/#Subject> <http://example.org/#predicateOne> <http://example.org/#ObjectA> .
+<http://example.org/#Subject> <http://example.org/#predicateOne> <http://example.org/#ObjectB> .
+<http://example.org/#Subject> <http://example.org/#predicateTwo> <http://example.org/#ObjectC> .
+<http://example.org/#Subject> <http://example.org/#predicateTwo> <http://example.org/#ObjectD> .

test/n3_tests/n3p/simple-07.n3

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+# simple-07.n3 - Popairs and multiple objects, mixed types
+
+@prefix : <http://example.org/#> .
+@prefix foaf: <http://xmlns.com/foaf/0.1/> .
+
+:Subject :predicateOne :ObjectP, <http://example.org/path#ObjectQ>; 
+         :predicateTwo [ foaf:nick "spiggot" ], "ObjectR", _:ObjectS .

test/n3_tests/n3p/simple-07.nt

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+<http://example.org/#Subject> <http://example.org/#predicateOne> <http://example.org/#ObjectP> .
+<http://example.org/#Subject> <http://example.org/#predicateOne> <http://example.org/path#ObjectQ> .
+<http://example.org/#Subject> <http://example.org/#predicateTwo> _:node1 .
+_:node1 <http://xmlns.com/foaf/0.1/nick> "spiggot" .
+<http://example.org/#Subject> <http://example.org/#predicateTwo> "ObjectR" .
+<http://example.org/#Subject> <http://example.org/#predicateTwo> _:ObjectS .