Add support for the annotated triples syntax

rdfjs · Jun 22, 2023 · 1d2a4e5 · 1d2a4e5
1 parent 312d5d5
commit 1d2a4e5
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Showing 4 changed files with 144 additions and 2 deletions.
diff --git a/src/N3Lexer.js b/src/N3Lexer.js
@@ -300,13 +300,35 @@ export default class N3Lexer {
       case ']':
       case '(':
       case ')':
-      case '{':
       case '}':
+        matchLength = 1;
+        type = firstChar;
+        break;
+      case '{':
         if (!this._lineMode) {
+          // We need at least 2 tokens lookahead to distinguish "{|" and "{ "
+          if (input.length < 2)
+            break;
+
+          // Try to find a quoted triple annotation start
+          if (input.length > 1 && input[1] === '|') {
+            type = '{|', matchLength = 2;
+            break;
+          }
+
           matchLength = 1;
           type = firstChar;
         }
         break;
+      case '|':
+        // We need at least 2 tokens lookahead to distinguish "|}" and "|"
+        if (input.length < 2)
+          break;
+        // Try to find a quoted triple annotation end
+        if (input[0] === '|' && input.length > 1 && input[1] === '}') {
+          type = '|}', matchLength = 2;
+          break;
+        }
 
       default:
         inconclusive = true;

diff --git a/src/N3Parser.js b/src/N3Parser.js
@@ -614,6 +614,23 @@ export default class N3Parser {
     case ',':
       next = this._readObject;
       break;
+    // {| means that the current triple is annotated with predicate-object pairs.
+    case '{|':
+      if (!this._supportsRDFStar)
+        return this._error('Unexpected RDF* syntax', token);
+
+      // Continue using the last triple as quoted triple subject for the predicate-object pairs.
+      const predicate = this._predicate, object = this._object;
+      this._subject = this._quad(subject, predicate, object, this.DEFAULTGRAPH);
+      next = this._readPredicate;
+      break;
+    // |} means that the current quoted triple in annotation syntax is finalized.
+    case '|}':
+      if (this._subject.termType !== 'Quad')
+        return this._error('Unexpected asserted triple closing', token);
+      this._subject = null;
+      next = this._readPunctuation;
+      break;
     default:
       // An entity means this is a quad (only allowed if not already inside a graph)
       if (this._supportsQuads && this._graph === null && (graph = this._readEntity(token)) !== undefined) {

diff --git a/test/N3Lexer-test.js b/test/N3Lexer-test.js
@@ -1090,6 +1090,49 @@ describe('Lexer', () => {
         { type: '.', line: 1 },
         { type: 'eof', line: 1 }));
 
+    it('should tokenize a quoted triple annotation start',
+        shouldTokenize('{|',
+            { type: '{|', line: 1 },
+            { type: 'eof', line: 1 }));
+
+    it('should tokenize a split quoted triple annotation start',
+        shouldTokenize(streamOf('{', '|'),
+            { type: '{|', line: 1 },
+            { type: 'eof', line: 1 }));
+
+    it('should tokenize a quoted triple annotation end',
+        shouldTokenize('|}',
+            { type: '|}', line: 1 },
+            { type: 'eof', line: 1 }));
+
+    it('should tokenize a split quoted triple annotation end',
+        shouldTokenize(streamOf('|', '}'),
+            { type: '|}', line: 1 },
+            { type: 'eof', line: 1 }));
+
+    it('should tokenize an empty quoted triple annotation',
+        shouldTokenize('{| |}',
+            { type: '{|', line: 1 },
+            { type: '|}', line: 1 },
+            { type: 'eof', line: 1 }));
+
+    it('should tokenize a non-empty quoted triple annotation',
+        shouldTokenize('{| <http://ex.org/?bla#bar> \n\t<http://ex.org/?bla#boo> |}.',
+            { type: '{|', line: 1 },
+            { type: 'IRI', value: 'http://ex.org/?bla#bar', line: 1 },
+            { type: 'IRI', value: 'http://ex.org/?bla#boo', line: 2 },
+            { type: '|}', line: 2 },
+            { type: '.', line: 2 },
+            { type: 'eof', line: 2 }));
+
+    it('should not tokenize an incomplete closing triple annotation',
+        shouldNotTokenize('{| |',
+            'Unexpected "|" on line 1.'));
+
+    it('should not tokenize an invalid closing triple annotation',
+        shouldNotTokenize('{| ||',
+            'Unexpected "||" on line 1.'));
+
     it('returns start and end index for every token', () => {
       const tokens = new Lexer().tokenize('<a:a> <b:c> "lit"@EN.');
       tokens.should.deep.equal([

diff --git a/test/N3Parser-test.js b/test/N3Parser-test.js
@@ -746,7 +746,7 @@ describe('Parser', () => {
 
     it('should not parse a single opening brace',
       shouldNotParse('{',
-                     'Expected entity but got eof on line 1.'));
+                     'Unexpected "{" on line 1.'));
 
     it('should not parse a superfluous closing brace ',
       shouldNotParse('{}}',
@@ -1044,6 +1044,46 @@ describe('Parser', () => {
       shouldParse('<a> <b> <c> <g>.\n<<<a> <b> <c>>> <d> <e>.',
           ['a', 'b', 'c', 'g'],
           [['a', 'b', 'c'], 'd', 'e']));
+
+    it('should parse an RDF* triple using annotation syntax with one predicate-object',
+      shouldParse('<a> <b> <c> {| <b> <c> |}.',
+          ['a', 'b', 'c'], [['a', 'b', 'c'], 'b', 'c']));
+
+    it('should parse an RDF* triple using annotation syntax with two predicate-objects',
+        shouldParse('<a> <b> <c> {| <b1> <c1>; <b2> <c2> |}.',
+            ['a', 'b', 'c'], [['a', 'b', 'c'], 'b1', 'c1'], [['a', 'b', 'c'], 'b2', 'c2']));
+
+    it('should parse an RDF* triple using annotation syntax with one predicate-object followed by regular triples',
+        shouldParse('<a> <b> <c> {| <b> <c> |}.\n<a2> <b2> <c2>.',
+            ['a', 'b', 'c'], [['a', 'b', 'c'], 'b', 'c'], ['a2', 'b2', 'c2']));
+
+    it('should not parse an RDF* triple using annotation syntax with zero predicate-objects',
+        shouldNotParse('<a> <b> <c> {| |}',
+            'Expected entity but got |} on line 1.'));
+
+    it('should not parse an RDF* triple using an incomplete annotation syntax',
+        shouldNotParse('<a> <b> <c> {| <b> |}',
+            'Expected entity but got |} on line 1.'));
+
+    it('should not parse an RDF* triple using an incomplete annotation syntax after a semicolon',
+        shouldNotParse('<a> <b> <c> {| <b1> <c1>; |}',
+            'Expected entity but got |} on line 1.'));
+
+    it('should not parse an RDF* triple using an incomplete annotation syntax after a semicolon and entity',
+        shouldNotParse('<a> <b> <c> {| <b1> <c1>; <b2> |}',
+            'Expected entity but got |} on line 1.'));
+
+    it('should not parse an RDF* triple using an incomplete annotation syntax that misses |}',
+        shouldNotParse('<a> <b> <c> {| <b1> <c1>',
+            'Expected entity but got eof on line 1.'));
+
+    it('should not parse an RDF* triple using an incomplete annotation syntax that misses |} and starts a new subject',
+        shouldNotParse('<a> <b> <c> {| <b1> <c1>. <a2> <b2> <c2>',
+            'Expected entity but got eof on line 1.'));
+
+    it('should not parse an out of place |}',
+        shouldNotParse('<a> <b> <c> |}',
+            'Unexpected asserted triple closing on line 1.'));
   });
 
   describe('An Parser instance without document IRI', () => {
@@ -1227,6 +1267,10 @@ describe('Parser', () => {
     it('should not parse RDF* in the object position',
       shouldNotParse(parser, '<a> <b> <<a> <b> <c>>>.',
         'Unexpected RDF* syntax on line 1.'));
+
+    it('should not parse RDF* with annotated syntax',
+        shouldNotParse(parser, '<a> <b> <c> {| <b> <c> |}.',
+            'Unexpected RDF* syntax on line 1.'));
   });
 
   describe('A Parser instance for the TurtleStar format', () => {
@@ -1288,6 +1332,10 @@ describe('Parser', () => {
     it('should not parse RDF* in the object position',
       shouldNotParse(parser, '<a> <b> <<<a> <b> <c>>>.',
         'Unexpected RDF* syntax on line 1.'));
+
+    it('should not parse RDF* with annotated syntax',
+        shouldNotParse(parser, '<a> <b> <c> {| <b> <c> |}.',
+            'Unexpected RDF* syntax on line 1.'));
   });
 
   describe('A Parser instance for the TriGStar format', () => {
@@ -1375,6 +1423,10 @@ describe('Parser', () => {
     it('should not parse nested quads',
       shouldNotParse(parser, '<<_:a <http://ex.org/b> _:b <http://ex.org/b>>> <http://ex.org/b> "c" .',
         'Expected >> to follow "_:b0_b" on line 1.'));
+
+    it('should not parse annotated triples',
+        shouldNotParse(parser, '_:a <http://ex.org/b> _:c {| <http://ex.org/b1> "c1" |} .',
+            'Unexpected "{|" on line 1.'));
   });
 
   describe('A Parser instance for the N-Quads format', () => {
@@ -1430,6 +1482,10 @@ describe('Parser', () => {
     it('should parse RDF*',
       shouldParse(parser, '<<_:a <http://example.org/b> _:c>> <http://example.org/a> _:c .',
         [['_:b0_a', 'b', '_:b0_c'], 'a', '_:b0_c']));
+
+    it('should not parse annotated triples',
+        shouldNotParse(parser, '_:a <http://ex.org/b> _:c {| <http://ex.org/b1> "c1" |} .',
+            'Unexpected "{|" on line 1.'));
   });
 
   describe('A Parser instance for the N3 format', () => {
@@ -1777,6 +1833,10 @@ describe('Parser', () => {
     it('should not parse RDF* in the object position',
       shouldNotParse(parser, '<a> <b> <<<a> <b> <c>>>.',
         'Unexpected RDF* syntax on line 1.'));
+
+    it('should not parse RDF* with annotated syntax',
+        shouldNotParse(parser, '<a> <b> <c> {| <b> <c> |}.',
+            'Unexpected RDF* syntax on line 1.'));
   });
 
   describe('A Parser instance for the N3Star format', () => {