Method optimize

basex-core/src/main/java/org/basex/query/expr/Range.java:39–67

(final CompileContext cc)

  }

  @Override
  public Expr optimize(final CompileContext cc) throws QueryException {
    exprs = simplifyAll(Simplify.NUMBER, cc);

    Expr expr = emptyExpr();
    if(expr == this) {
      if(values(false, cc)) return cc.preEval(this);

      final Expr min = exprs[0], max = exprs[1];
      if(!min.has(Flag.NDT)) {
        if(min.equals(max)) {
          // identical operands: $int to $int
          exprType.assign(Occ.EXACTLY_ONE);
          if(integers()) expr = min;
        } else if(max instanceof final Arith arith && min.equals(max.arg(0))) {
          if(arith.calc.oneOf(Calc.ADD, Calc.SUBTRACT) && arith.arg(1) instanceof final Itr itr) {
            // known result size: . to . + 10
            final long n = (arith.calc == Calc.ADD ? itr.itr() : -itr.itr()) + 1;
            if(n < 1) {
              expr = Empty.VALUE;
            } else {
              exprType.assign(seqType(), n);
            }
          }
        }
      }
    }
    return cc.replaceWith(this, expr);
  }

  /**
   * Indicates if the range operands are known to return single integers.