ZIO learning - playing with streams - find files / published by https://github.com/dacr/code-examples-manager #5d6e5df8-c059-4fe5-a1a2-a9a8233f601a/c4b7c7a0bacddefd1636b0670b06b9f4d0253940

zio-learning-streams-4-find.sc

// summary : ZIO learning - playing with streams - find files
// keywords : scala, zio, learning, streams, find, regex, @testable
// publish : gist
// authors : zio
// license : Apache License Version 2.0 (https://www.apache.org/licenses/LICENSE-2.0.txt)
// id : 5d6e5df8-c059-4fe5-a1a2-a9a8233f601a
// created-on : 2021-11-28T17:58:10+01:00
// managed-by : https://github.com/dacr/code-examples-manager
// run-with : scala-cli $file

// ---------------------
//> using scala "3.4.2"
//> using dep "dev.zio::zio:2.0.13"
//> using dep "dev.zio::zio-streams:2.0.13"
// ---------------------

import zio.*
import zio.stream.*

import java.nio.file.attribute.BasicFileAttributes
import java.nio.file.{Files, Path, Paths}
import scala.util.matching.Regex

object App extends ZIOAppDefault {
  case class IssueInvalidSearchPath(th: Throwable)
  case class IssueInvalidRegexPattern(th: Throwable)
  case class IssueJavaFind(th: Throwable)
  case class IssueFindCollectResult(th: Throwable)

  type FindIssues = IssueInvalidSearchPath | IssueInvalidRegexPattern | IssueJavaFind | IssueFindCollectResult

  def searchPredicate(ignoreMaskRegex: Option[Regex])(path: Path, attrs: BasicFileAttributes): Boolean =
    attrs.isRegularFile && (
      ignoreMaskRegex.isEmpty || ignoreMaskRegex.get.findFirstIn(path.toString).isDefined
    )

  def find(searchRoot: String, findPattern: Option[String]): ZIO[Any, FindIssues, Chunk[Path]] =
    for
      searchPath <- ZIO.attempt(Path.of(searchRoot)).mapError(th => IssueInvalidSearchPath(th))
      findRegex  <- ZIO.attempt(findPattern.map(_.r)).mapError(th => IssueInvalidRegexPattern(th))
      javaStream <- ZIO.attempt(Files.find(searchPath, 10, searchPredicate(findRegex))).mapError(th => IssueJavaFind(th))
      results    <- ZStream.fromJavaStream(javaStream).runCollect.mapError(th => IssueFindCollectResult(th))
    yield results

  override def run =
    for {
      results <- find(searchRoot = ".", Some(".*"))
      _       <- ZIO.foreach(results)(path => Console.printLine(path))
    } yield ()

}

App.main(Array.empty)