Method optimize

basex-core/src/main/java/org/basex/query/expr/CmpV.java:40–63

(final CompileContext cc)

  }

  @Override
  public Expr optimize(final CompileContext cc) throws QueryException {
    exprs = simplifyAll(Simplify.STRING, cc);
    if(values(false, cc)) return cc.preEval(this);

    // swap operands
    if(swap()) {
      cc.info(OPTSWAP_X, this);
      Collections.reverse(Arrays.asList(exprs));
      op = op.swap();
    }

    Expr expr = emptyExpr();
    if(expr == this) expr = toGeneral(cc, true);
    if(expr == this) expr = opt(cc);
    if(expr == this) {
      // restrict type
      final SeqType st1 = exprs[0].seqType(), st2 = exprs[1].seqType();
      if(st1.oneOrMore() && !st1.mayBeWrapped() && st2.oneOrMore() && !st2.mayBeWrapped()) {
        exprType.assign(Occ.EXACTLY_ONE);
      }
    }
    return cc.replaceWith(this, expr);
  }

  @Override
  public Expr simplifyFor(final Simplify mode, final CompileContext cc) throws QueryException {