type Clause struct {
	Name                string // WHERE
	BeforeExpression    Expression
	AfterNameExpression Expression
	AfterExpression     Expression
	Expression          Expression
	Builder             ClauseBuilder
}

// Build build clause
func (c Clause) Build(builder Builder) {
	if c.Builder != nil {
		c.Builder(c, builder)
	} else if c.Expression != nil {
		if c.BeforeExpression != nil {
			c.BeforeExpression.Build(builder)

        boostExpression = expression;
    }

    /**
     * Gets the current match expression.
     *
     * @return the match expression string
     */
    public String getMatchExpression() {
        return matchExpression;
    }

    /**
     * Sets the match expression used to determine if documents should be boosted.
     *
     * @param expression the match expression string
     */

        List<Expression> expressions = documentation.getExpressions();

        Map<String, Expression> bySyntax = new HashMap<>();

        if (expressions != null && !expressions.isEmpty()) {
            for (Expression expression : expressions) {
                bySyntax.put(expression.getSyntax(), expression);
            }
        }

        return bySyntax;
    }

  @JvmName("-deprecated_url")
  @Deprecated(
    message = "moved to val",
    replaceWith = ReplaceWith(expression = "url"),
    level = DeprecationLevel.ERROR,
  )
  fun url(): HttpUrl = url

  @JvmName("-deprecated_dns")
  @Deprecated(
    message = "moved to val",
    replaceWith = ReplaceWith(expression = "dns"),
    level = DeprecationLevel.ERROR,
  )
  fun dns(): Dns = dns

type Join struct {
	Type       JoinType
	Table      Table
	ON         Where
	Using      []string
	Expression Expression
}

func JoinTable(names ...string) Table {
	return Table{
		Name: utils.JoinNestedRelationNames(names),
	}
}

func (join Join) Build(builder Builder) {
	if join.Expression != nil {
		join.Expression.Build(builder)
	} else {
		if join.Type != "" {
			builder.WriteString(string(join.Type))

	column := "column-name"
	results := []struct {
		Expressions  []clause.Expression
		ExpectedVars []interface{}
		Result       string
	}{{
		Expressions: []clause.Expression{
			clause.Eq{Column: column, Value: "column-value"},
		},
		ExpectedVars: []interface{}{"column-value"},
		Result:       "`column-name` = ?",
	}, {
		Expressions: []clause.Expression{
			clause.Eq{Column: column, Value: nil},

			},
			sql: "INNER JOIN `user` USING (`id`)",
		},
		{
			name: "Expression",
			join: clause.Join{
				// Invalid
				Type:  clause.LeftJoin,
				Table: clause.Table{Name: "user"},
				ON: clause.Where{
					Exprs: []clause.Expression{clause.Eq{clause.Column{Table: "user_info", Name: "user_id"}, clause.PrimaryColumn}},
				},
				// Valid
				Expression: clause.Join{
					Type:  clause.InnerJoin,

    /**
     * Adds a client with a regular expression pattern.
     * @param regex The regular expression to match URLs.
     * @param client The CrawlerClient instance.
     */
    public void addClient(final String regex, final CrawlerClient client) {
        if (StringUtil.isBlank(regex)) {
            throw new CrawlerSystemException(

     */
    @Override
    public Object getValue(String expression) {
        if (expression == null || expression.trim().isEmpty()) {
            return null;
        }

        try {
            return ReflectionValueExtractor.evaluate(expression, root, false);
        } catch (Exception e) {
            addFeedback("Failed to extract \'" + expression + "\' from: " + root, e);
        }

        return null;
    }

                    .toList();
            for (String expression : expressions) {
                if ("h".equals(expression)) {
                    filters.add(new HighestVersionFilter());
                } else if (expression.startsWith("h(") && expression.endsWith(")")) {
                    int num = Integer.parseInt(expression.substring(2, expression.length() - 1));
                    filters.add(new HighestVersionFilter(num));