How to use

OptionalBlock

in

com.mysema.rdfbean.model

public static OptionalBlock optional(List<Block> blocks, Predicate... predicates) {
  return new OptionalBlock(blocks, predicates);
}

@Override
public Void visit(OptionalBlock expr, Void context) {
  handle(expr.getBlocks());
  handle(expr.getFilters());
  return null;
}

@SuppressWarnings("unchecked")
@Override
public <R, C> R accept(Visitor<R, C> v, C context) {
  if (v instanceof RDFVisitor) {
    return (R) ((RDFVisitor) v).visit(this, context);
  } else if (v instanceof ToStringVisitor) {
    return (R) toString();
  } else if (v.getClass().getName().equals("com.mysema.query.types.ExtractorVisitor")) {
    return (R) this;
  } else {
    throw new IllegalArgumentException(v.toString());
  }
}

@Test
public void Exists() {
  assertEquals("exists OPTIONAL { {s} {p} {o} {c} .  }", Blocks.optional(Blocks.SPOC).exists().toString());
}

@Nullable
public Void visit(OptionalBlock expr, @Nullable Void context) {
  lastPattern = null;
  append("OPTIONAL { ");
  visitBlocks(expr.getBlocks());
  visitFilter(expr.getFilters());
  append("} ");
  lastPattern = null;
  return null;
}

public static OptionalBlock optional(Block... blocks) {
  return new OptionalBlock(Arrays.asList(blocks));
}

public static OptionalBlock optionalFilter(Block block, Predicate... predicates) {
  return new OptionalBlock(Collections.singletonList(block), predicates);
}