Class Single

basex-core/src/main/java/org/basex/query/expr/Single.java:18–128

Abstract single expression. @author BaseX Team, BSD License @author Christian Gruen

 * @author Christian Gruen
 */
public abstract class Single extends ParseExpr {
  /** Expression. */
  public Expr expr;

  /**
   * Constructor.
   * @param info input info (can be {@code null})
   * @param expr expression (can be {@code null})
   * @param seqType sequence type
   */
  protected Single(final InputInfo info, final Expr expr, final SeqType seqType) {
    super(info, seqType);
    this.expr = expr;
  }

  @Override
  public void checkUp() throws QueryException {
    checkNoUp(expr);
  }

  @Override
  public Expr compile(final CompileContext cc) throws QueryException {
    expr = expr.compile(cc);
    return optimize(cc);
  }

  @Override
  public Expr optimize(final CompileContext cc) throws QueryException {
    return expr instanceof Value ? cc.preEval(this) : this;
  }

  @Override
  public boolean has(final Flag... flags) {
    return expr.has(flags);
  }

  @Override
  public boolean inlineable(final InlineContext ic) {
    return expr.inlineable(ic);
  }

  @Override
  public VarUsage count(final Var var) {
    return expr.count(var);
  }

  @Override
  public Expr inline(final InlineContext ic) throws QueryException {
    final Expr inlined = expr.inline(ic);
    if(inlined == null) return null;
    expr = inlined;
    return optimize(ic.cc);
  }

  @Override
  public boolean accept(final ASTVisitor visitor) {
    return expr.accept(visitor);
  }