add blank node functionality

src/main/java/com/anqit/spanqit/constraint/ConnectiveOperation.java

@@ -3,9 +3,6 @@
 /**
  * Represents a SPARQL connective operation, which takes an arbitrary number of
  * arguments
- * 
- * @author Ankit
- *
  */
 class ConnectiveOperation extends Operation<ConnectiveOperation> {
 	ConnectiveOperation(ConnectiveOperator operator) {

src/main/java/com/anqit/spanqit/constraint/Expression.java

@@ -12,7 +12,6 @@
  * A SPARQL expression. Used by filters, having clauses, order and group by
  * clauses, assignments, and as arguments to other expressions.
  *
- * @author Ankit
  * @param <T>
  *            the type of Expression (ie, Function or Operation). Used to
  *            support fluency

src/main/java/com/anqit/spanqit/constraint/ExpressionOperand.java

@@ -5,8 +5,5 @@
 /**
  * An element that can be used as an operand to an
  * {@link com.anqit.spanqit.constraint.Expression}
- * 
- * @author Ankit
- *
  */
 public interface ExpressionOperand extends QueryElement { }

src/main/java/com/anqit/spanqit/constraint/Expressions.java

@@ -18,8 +18,6 @@
  * @see <a
  *      href="http://www.w3.org/TR/2013/REC-sparql11-query-20130321/#SparqlOps">
  *      SPARQL Function Definitions</a>
- * @author Ankit
- *
  */
 public class Expressions {
 	// prevent instantiation of this class

src/main/java/com/anqit/spanqit/core/Prefix.java

@@ -5,8 +5,6 @@
 /**
  * A SPARQL Prefix declaration
  * 
- * @author Ankit
- *
  * @see <a
  *      href="http://www.w3.org/TR/2013/REC-sparql11-query-20130321/#prefNames">
  *      SPARQL Prefix</a>

src/main/java/com/anqit/spanqit/core/PrefixDeclarations.java

@@ -3,8 +3,6 @@
 /**
  * A collection of SPARQL Prefix declarations
  * 
- * @author Ankit
- *
  * @see <a
  *      href="http://www.w3.org/TR/2013/REC-sparql11-query-20130321/#prefNames">
  *      SPARQL Prefix</a>

src/main/java/com/anqit/spanqit/core/Projection.java

@@ -5,8 +5,6 @@
 /**
  * A SPARQL Projection
  * 
- * @author Ankit
- *
  * @see <a
  *      href="http://www.w3.org/TR/2013/REC-sparql11-query-20130321/#selectproject">
  *      SPARQL Projections</a>

src/main/java/com/anqit/spanqit/core/Query.java

@@ -186,7 +186,7 @@ public T offset(int offset) {
 	 * @return a SparqlVariable object that is unique to this query instance
 	 */
 	public Variable var() {
-		return new Variable("x" + ++varCount);
+		return Spanqit.var("x" + ++varCount);
 	}
 
 	protected abstract String getQueryActionString();

src/main/java/com/anqit/spanqit/core/QueryPattern.java

@@ -7,8 +7,6 @@
 /**
  * A SPARQL Query Pattern (<code>WHERE</code> clause)
  * 
- * @author Ankit
- *
  * @see <a
  *      href="http://www.w3.org/TR/2013/REC-sparql11-query-20130321/#GraphPattern">
  *      Query Pattern Definition</a>

src/main/java/com/anqit/spanqit/core/Spanqit.java

@@ -7,9 +7,6 @@
 
 /**
  * A class to with static methods to create SPARQL query elements.
- * 
- * @author Ankit
- * 
  */
 public class Spanqit {
 	// prevent instantiation of this class

src/main/java/com/anqit/spanqit/core/SpanqitStringUtils.java

@@ -10,10 +10,14 @@ public static void appendAndNewlineIfNonNull(QueryElement element, StringBuilder
 		builder.append(Optional.ofNullable(element).map(e -> e.getQueryString() + "\n").orElse(""));
 	}
 
-	public static String getBracketedString(String contents) {
+	public static String getBracedString(String contents) {
 		return getEnclosedString("{", "}", contents);
 	}
 
+	public static String getBracketedString(String contents) {
+		return getEnclosedString("[", "]", contents);
+	}
+
 	public static String getParenthesizedString(String contents) {
 		return getEnclosedString("(", ")", contents);
 	}

src/main/java/com/anqit/spanqit/core/Variable.java

@@ -9,8 +9,6 @@
 /**
  * A SPARQL query variable
  * 
- * @author Ankit
- *
  * @see <a
  *      href="http://www.w3.org/TR/2013/REC-sparql11-query-20130321/#QSynVariables">
  *      SPARQL Variable Syntax</a>

src/main/java/com/anqit/spanqit/graphpattern/BNodeTriplePattern.java

@@ -0,0 +1,36 @@
+package com.anqit.spanqit.graphpattern;
+
+import com.anqit.spanqit.rdf.RdfBlankNode.PropertiesBlankNode;
+import com.anqit.spanqit.rdf.RdfObject;
+import com.anqit.spanqit.rdf.RdfPredicate;
+
+/**
+ * A triple pattern formed by a property-list blank node
+ * 
+ * @see <a href="https://www.w3.org/TR/2013/REC-sparql11-query-20130321/#QSynBlankNodes">
+ * 		blank node syntax</a>
+ */
+class BNodeTriplePattern implements TriplePattern<BNodeTriplePattern> {
+	private PropertiesBlankNode bnode;
+
+	BNodeTriplePattern(PropertiesBlankNode subject) {
+		this.bnode = subject;
+	}
+
+	@Override
+	public BNodeTriplePattern andHas(RdfPredicate predicate, RdfObject... objects) {
+		bnode.andHas(predicate, objects);
+
+		return this;
+	}
+
+	@Override
+	public boolean isEmpty() {
+		return false;
+	}
+
+	@Override
+	public String getQueryString() {
+		return bnode.getQueryString() + SUFFIX;
+	}
+}

src/main/java/com/anqit/spanqit/graphpattern/GraphPattern.java

@@ -5,8 +5,6 @@
 /**
  * Denotes a SPARQL Graph Pattern
  * 
- * @author Ankit
- *
  * @see <a
  *      href="http://www.w3.org/TR/2013/REC-sparql11-query-20130321/#GraphPattern">
  *      SPARQL Graph Patterns</a>

src/main/java/com/anqit/spanqit/graphpattern/GraphPatterns.java

@@ -1,24 +1,21 @@
 package com.anqit.spanqit.graphpattern;
 
 import com.anqit.spanqit.core.Projectable;
+import com.anqit.spanqit.rdf.RdfBlankNode.PropertiesBlankNode;
 import com.anqit.spanqit.rdf.RdfObject;
 import com.anqit.spanqit.rdf.RdfPredicate;
 import com.anqit.spanqit.rdf.RdfSubject;
 
 /**
- * A class with static methods to create graph patterns. Obviously there's some
- * more flushing out TODO still
+ * A class with static methods to create graph patterns.
  * 
- * @author Ankit
- *
  * @see <a
  *      href="http://www.w3.org/TR/2013/REC-sparql11-query-20130321/#GraphPattern">SPARQL
  *      Graph Pattern</a>
  */
 public class GraphPatterns {
 	// prevent instantiation of this class
-	private GraphPatterns() {
-	}
+	private GraphPatterns() { }
 
 	/**
 	 * Create a triple pattern with the given subject, predicate, and object(s)
@@ -33,9 +30,21 @@ private GraphPatterns() {
 	 *      href="http://www.w3.org/TR/2013/REC-sparql11-query-20130321/#QSynTriples">
 	 *      Triple pattern syntax</a>
 	 */
-	public static TriplePattern tp(RdfSubject subject,
-			RdfPredicate predicate, RdfObject... objects) {
-		return new TriplePattern(subject, predicate, objects);
+	public static TriplePattern tp(RdfSubject subject, RdfPredicate predicate, RdfObject... objects) {
+		return new TriplesSameSubject(subject, predicate, objects);
+	}
+
+	/**
+	 * Create a triple pattern from a property-list blank node
+	 * @param bnode the PropertiesBlankNode instance to convert to a triple pattern
+	 * 
+	 * @return the triple pattern represented by the expansion of this blank node
+	 * 
+	 * @see <a href="https://www.w3.org/TR/2013/REC-sparql11-query-20130321/#QSynBlankNodes">
+	 * 		blank node syntax</a>
+	 */
+	public static TriplePattern tp(PropertiesBlankNode bnode) {
+		return new BNodeTriplePattern(bnode);
 	}
 
 	/**

src/main/java/com/anqit/spanqit/graphpattern/GroupGraphPattern.java

@@ -95,7 +95,7 @@ public String getQueryString() {
 		}
 
 		if (bracketize) {
-			pattern.append(SpanqitStringUtils.getBracketedString(innerPattern
+			pattern.append(SpanqitStringUtils.getBracedString(innerPattern
 					.toString()));
 		} else {
 			pattern.append(innerPattern.toString());

src/main/java/com/anqit/spanqit/graphpattern/SubSelect.java

@@ -9,8 +9,6 @@
 /**
  * A SPARQL subquery
  * 
- * @author Ankit
- * 
  * @see <a
  *      href="http://www.w3.org/TR/2013/REC-sparql11-query-20130321/#subqueries">
  *      SPARQL Subquery</a>
@@ -140,6 +138,6 @@ public String getQueryString() {
 		// TODO: VALUES
 		// subselect.append(values.getQueryString());
 
-		return SpanqitStringUtils.getBracketedString(subSelect.toString());
+		return SpanqitStringUtils.getBracedString(subSelect.toString());
 	}
 }

src/main/java/com/anqit/spanqit/graphpattern/TriplePattern.java

@@ -1,54 +1,28 @@
-package com.anqit.spanqit.graphpattern;
-
-import com.anqit.spanqit.core.QueryElementCollection;
-import com.anqit.spanqit.rdf.RdfObject;
-import com.anqit.spanqit.rdf.RdfPredicate;
-import com.anqit.spanqit.rdf.RdfSubject;
-
-/**
- * A SPARQL Triple Pattern.
- * 
- * @see <a
- *      href="http://www.w3.org/TR/2013/REC-sparql11-query-20130321/#QSynTriples">
- *      Triple pattern syntax</a>
- */
-public class TriplePattern extends QueryElementCollection<RdfPredicateRdfObjectListPair> implements GraphPattern {
-	private RdfSubject subject;
-
-	TriplePattern(RdfSubject subject, RdfPredicate predicate,
-			RdfObject... objects) {
-		super(" ;\n\t");
-		this.subject = subject;
-		andHas(predicate, objects);
-	}
-
-	/**
-	 * Using the predicate-object and object list mechanisms, expand this triple pattern to include
-	 * triples consisting of this subject, and the given predicate and object(s)
-	 * 
-	 * @param predicate the predicate of the triple to add
-	 * @param objects the object or objects of the triple to add
-	 * 
-	 * @return this triple pattern
-	 * 
-	 * @see <a href="https://www.w3.org/TR/2013/REC-sparql11-query-20130321/#predObjLists">
-	 * 		Predicate-Object Lists</a>
-	 * @see <a href="https://www.w3.org/TR/2013/REC-sparql11-query-20130321/#objLists">
-	 * 		Object Lists</a>
-	 */
-	public TriplePattern andHas(RdfPredicate predicate, RdfObject... objects) {
-		elements.add(new RdfPredicateRdfObjectListPair(predicate, objects));
-
-		return this;
-	}
-
-	@Override
-	public boolean isEmpty() {
-		return false;
-	}
-
-	@Override
-	public String getQueryString() {
-		return subject.getQueryString() + " " + super.getQueryString() + " .";
-	}
-}
+package com.anqit.spanqit.graphpattern;
+
+import com.anqit.spanqit.rdf.RdfObject;
+import com.anqit.spanqit.rdf.RdfPredicate;
+
+/**
+ * Denotes a SPARQL Triple Pattern
+ *
+ * @param <T> the type of triple pattern; used to support fluency
+ * 
+ * @see <a
+ *      href="http://www.w3.org/TR/2013/REC-sparql11-query-20130321/#QSynTriples">
+ *      Triple pattern syntax</a>
+ * @see <a href="https://www.w3.org/TR/2013/REC-sparql11-query-20130321/#QSynBlankNodes">
+ * 		blank node syntax</a>     
+ */
+public interface TriplePattern<T extends TriplePattern<T>> extends GraphPattern {
+	static String SUFFIX = " .";
+
+	/**
+	 * add predicate-object lists describing this triple pattern's subject
+	 * 
+	 * @param predicate the predicate to use to describe this triple pattern's subject
+	 * @param objects the corresponding object(s) 
+	 * @return this triple pattern
+	 */
+	public T andHas(RdfPredicate predicate, RdfObject... objects);
+}

src/main/java/com/anqit/spanqit/graphpattern/TriplesSameSubject.java

@@ -0,0 +1,55 @@
+package com.anqit.spanqit.graphpattern;
+
+import com.anqit.spanqit.rdf.Rdf;
+import com.anqit.spanqit.rdf.RdfObject;
+import com.anqit.spanqit.rdf.RdfPredicate;
+import com.anqit.spanqit.rdf.RdfPredicateObjectListCollection;
+import com.anqit.spanqit.rdf.RdfSubject;
+
+/**
+ * A SPARQL Triple Pattern.
+ * 
+ * @see <a
+ *      href="http://www.w3.org/TR/2013/REC-sparql11-query-20130321/#QSynTriples">
+ *      Triple pattern syntax</a>
+ */
+class TriplesSameSubject implements TriplePattern<TriplesSameSubject> {
+	private RdfSubject subject;
+	private RdfPredicateObjectListCollection predicateObjectLists = Rdf.predicateObjectListCollection();
+
+	TriplesSameSubject(RdfSubject subject, RdfPredicate predicate, RdfObject... objects) {
+		this.subject = subject;
+		andHas(predicate, objects);
+	}
+
+	/**
+	 * Using the predicate-object and object list mechanisms, expand this triple pattern to include
+	 * triples consisting of this subject, and the given predicate and object(s)
+	 * 
+	 * @param predicate the predicate of the triple to add
+	 * @param objects the object or objects of the triple to add
+	 * 
+	 * @return this triple pattern
+	 * 
+	 * @see <a href="https://www.w3.org/TR/2013/REC-sparql11-query-20130321/#predObjLists">
+	 * 		Predicate-Object Lists</a>
+	 * @see <a href="https://www.w3.org/TR/2013/REC-sparql11-query-20130321/#objLists">
+	 * 		Object Lists</a>
+	 */
+	@Override
+	public TriplesSameSubject andHas(RdfPredicate predicate, RdfObject... objects) {
+		predicateObjectLists.andHas(predicate, objects);
+
+		return this;
+	}
+
+	@Override
+	public boolean isEmpty() {
+		return false;
+	}
+
+	@Override
+	public String getQueryString() {
+		return subject.getQueryString() + " " + predicateObjectLists.getQueryString() + SUFFIX;
+	}
+}

src/main/java/com/anqit/spanqit/rdf/Rdf.java

@@ -0,0 +1,13 @@
+package com.anqit.spanqit.rdf;
+
+/**
+ * A class with static methods to create basic RDF objects
+ */
+public class Rdf {
+
+	private Rdf() { 	}
+
+	public static RdfPredicateObjectListCollection predicateObjectListCollection() {
+		return new RdfPredicateObjectListCollection();
+	}
+}