New to sqlparser, how could I quickly understand AST about vitess-sqlparser HOT 1 CLOSED

package main

import (
	"fmt"

	"github.com/knocknote/vitess-sqlparser/sqlparser"
)

func main() {
	stmt, err := sqlparser.Parse("select hello, good from user_items where user_id = 1 limit 10")
	if err != nil {
		panic(err)
	}
	tableName := stmt.(*sqlparser.Select).From[0].(*sqlparser.AliasedTableExpr).Expr.(sqlparser.TableName).Name.String()

	selectCol0 := stmt.(*sqlparser.Select).SelectExprs[0].(*sqlparser.AliasedExpr).Expr.(*sqlparser.ColName).Name.String()
	selectCol1 := stmt.(*sqlparser.Select).SelectExprs[1].(*sqlparser.AliasedExpr).Expr.(*sqlparser.ColName).Name.String()

	operator := stmt.(*sqlparser.Select).Where.Expr.(*sqlparser.ComparisonExpr).Operator

	leftVal := stmt.(*sqlparser.Select).Where.Expr.(*sqlparser.ComparisonExpr).Left.(*sqlparser.ColName).Name.String()

	rightVal := stmt.(*sqlparser.Select).Where.Expr.(*sqlparser.ComparisonExpr).Right.(*sqlparser.SQLVal).Val

	limitNum := stmt.(*sqlparser.Select).Limit.Rowcount.(*sqlparser.SQLVal).Val
	fmt.Printf("select %s, %s from %s where %s %s %s limit %s", selectCol0, selectCol1, tableName, leftVal, operator, string(rightVal), string(limitNum))
}