Class GraphPattern

java.lang.Object
org.eclipse.rdf4j.query.parser.sparql.GraphPattern
@InternalUseOnly public class GraphPattern extends Object
A graph pattern consisting of (required and optional) tuple expressions, binding assignments and boolean constraints.

  • Field Details

    • contextVar

      private Var contextVar
      The context of this graph pattern.

    • spScope

      private StatementPattern.Scope spScope
      The StatementPattern-scope of this graph pattern.

    • requiredTEs

      private final List<TupleExpr> requiredTEs
      The required tuple expressions in this graph pattern.

    • optionalTEs

      private final List<Map.Entry<TupleExpr, List<ValueExpr>>> optionalTEs
      The optional tuple expressions in this graph pattern, as a list of Key-Value pairs with the tuple expression as the key and a list of constraints applicable to the tuple expression as the value.

    • constraints

      private List<ValueExpr> constraints
      The boolean constraints in this graph pattern.

  • Constructor Details

    • GraphPattern

      public GraphPattern()
      Creates a new graph pattern.

    • GraphPattern

      public GraphPattern(GraphPattern parent)
      Creates a new graph pattern that inherits the context and scope from a parent graph pattern.

  • Method Details

    • setContextVar

      public void setContextVar(Var contextVar)

    • getContextVar

      public Var getContextVar()

    • setStatementPatternScope

      public void setStatementPatternScope(StatementPattern.Scope spScope)

    • getStatementPatternScope

      public StatementPattern.Scope getStatementPatternScope()

    • addRequiredTE

      public void addRequiredTE(TupleExpr te)

    • clearRequiredTEs

      void clearRequiredTEs()
      Remove all values for required tuple expressions in this GraphPattern

    • addRequiredSP

      public void addRequiredSP(Var subjVar, Var predVar, Var objVar)

    • getRequiredTEs

      public List<TupleExpr> getRequiredTEs()

    • addOptionalTE

      public void addOptionalTE(TupleExpr te, List<ValueExpr> constraints)
      add the supplied tuple expression as an optional expression, with a list of constraints that hold as conditions.
      Parameters:
      te - a tuple expression
      constraints - a list of constraints that form a condition for the LeftJoin to be formed from the optional TE.

    • getOptionalTEs

      public List<Map.Entry<TupleExpr, List<ValueExpr>>> getOptionalTEs()
      Retrieves the optional tuple expressions as a list of tuples with the tuple expression as the key and the list of value expressions as the value.
      Returns:
      a list of Map entries.

    • addConstraint

      public void addConstraint(ValueExpr constraint)

    • addConstraints

      public void addConstraints(Collection<ValueExpr> constraints)

    • getConstraints

      public List<ValueExpr> getConstraints()

    • removeAllConstraints

      public List<ValueExpr> removeAllConstraints()

    • clear

      public void clear()
      Removes all tuple expressions and constraints.

    • buildTupleExpr

      public TupleExpr buildTupleExpr()
      Builds a combined tuple expression from the tuple expressions and constraints in this graph pattern.
      Returns:
      A tuple expression for this graph pattern.

    • buildOptionalTE

      public TupleExpr buildOptionalTE(TupleExpr result)
      Build optionals to the supplied TE

    • buildJoinFromRequiredTEs

      TupleExpr buildJoinFromRequiredTEs()
      Build a single tuple expression representing _only_ the basic graph pattern, by joining the required TEs