Method uses

basex-core/src/main/java/org/basex/query/expr/Expr.java:242–251

Checks if the given variable is used by this expression. @param var variable to be checked @return true if the variable is used

(final Var var)

   * @return {@code true} if the variable is used
   */
  public final boolean uses(final Var var) {
    // return true iff the search was aborted, i.e. the variable is used
    return !accept(new ASTVisitor() {
      @Override
      public boolean used(final VarRef ref) {
        // abort when the variable is used
        return ref.var != var;
      }
    });
  }

  /**
   * Checks if inlining is possible.