Consider a Sink to mirror Source

[ekrich]

I know we are not wanting a big Scala library and such but this is where we could make some things easier for beginners or just for easy scripting. I was just doing some analysis on the sbt build for Scala Native and wrote the following. I think we could have something even easier than Python.

import scala.io.Source

val lines = Source
  .fromFile("config.txt")
  .getLines
  .toList
  .sorted
  .groupMapReduce[String, Int](identity)(_ => 1)(_ + _)
  .toList
  .map(t => t._1 + t._2)
  .sorted

val file = new java.io.FileWriter("config-out.txt")
for (line <- lines) file.write(line + "\n")
file.close()

[BalmungSan]

For the record, I think of an API like:

def writeToFile[A](path: Path, contents: IterableOnce[A])(formatLine: A => String): Try[Unit]

Maybe, even something like Sink to complement Source

trait Sink extends AutoClosable {
  def write(str: String): Unit

  final def writeLine(str:): Unit = {
    write(str)
    write(System.lineSeparator)
  }

  final def writeAllFormat[A](data: IterableOnce[A])(formatLine: A => String): Unit = {
    data.foreach(a => writeLine(formatLine(a)))
  }

  /** Uses toString */
  final def writeAll[A](data: IterableOnce[A]): Unit = {
    wrtieAllFormat(data)(_.toString)
  }

  def close(): Unit
}

object Sink {
  def fromFile(path: Path): Sink
}

Which then could be used with Using.

[SethTisue]

There's os-lib, which has been selected for the Scala Toolkit.