szleven

import org.apache.spark.sql.types._
import org.apache.spark.sql._

def findColumn(df: DataFrame, predicate: String => Boolean): Seq[String] = {
  def iterate(schema: StructType, matches: Seq[String] = Seq.empty, currentPath: String = ""): Seq[String] = {

    val prefix = if (currentPath.nonEmpty) currentPath + "." else ""

    schema.flatMap {
      case StructField(name, struct: StructType, _, _) => iterate(struct, matches, prefix + name)