cask.internal.Util.scala Maven / Gradle / Ivy

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package cask.internal

import java.io.{InputStream, PrintWriter, StringWriter}

import scala.collection.generic.CanBuildFrom
import scala.collection.mutable
import java.io.OutputStream

import scala.annotation.switch
import scala.concurrent.{ExecutionContext, Future, Promise}

object Util {
  def firstFutureOf[T](futures: Seq[Future[T]])(implicit ec: ExecutionContext) = {
    val p = Promise[T]
    futures.foreach(_.foreach(p.trySuccess))
    p.future
  }
  /**
    * Convert a string to a C&P-able literal. Basically
    * copied verbatim from the uPickle source code.
    */
  def literalize(s: IndexedSeq[Char], unicode: Boolean = true) = {
    val sb = new StringBuilder
    sb.append('"')
    var i = 0
    val len = s.length
    while (i < len) {
      (s(i): @switch) match {
        case '"' => sb.append("\\\"")
        case '\\' => sb.append("\\\\")
        case '\b' => sb.append("\\b")
        case '\f' => sb.append("\\f")
        case '\n' => sb.append("\\n")
        case '\r' => sb.append("\\r")
        case '\t' => sb.append("\\t")
        case c =>
          if (c < ' ' || (c > '~' && unicode)) sb.append("\\u%04x" format c.toInt)
          else sb.append(c)
      }
      i += 1
    }
    sb.append('"')

    sb.result()
  }

  def transferTo(in: InputStream, out: OutputStream) = {
    val buffer = new Array[Byte](8192)

    while ({
      in.read(buffer) match{
        case -1 => false
        case n =>
          out.write(buffer, 0, n)
          true
      }
    }) ()
  }
  def pluralize(s: String, n: Int) = {
    if (n == 1) s else s + "s"
  }

  /**
    * Splits a string into path segments; automatically removes all
    * leading/trailing slashes, and ignores empty path segments.
    *
    * Written imperatively for performance since it's used all over the place.
    */
  def splitPath(p: String): collection.IndexedSeq[String] = {
    val pLength = p.length
    var i = 0
    while(i < pLength && p(i) == '/') i += 1
    var segmentStart = i
    val out = mutable.ArrayBuffer.empty[String]

    def complete() = {
      if (i != segmentStart) {
        val s = p.substring(segmentStart, i)
        out += s
      }
      segmentStart = i + 1
    }

    while(i < pLength){
      if (p(i) == '/') complete()
      i += 1
    }
    complete()
    out
  }

  def stackTraceString(e: Throwable) = {
    val trace = new StringWriter()
    val pw = new PrintWriter(trace)
    e.printStackTrace(pw)
    pw.flush()
    trace.toString
  }
  def softWrap(s: String, leftOffset: Int, maxWidth: Int) = {
    val oneLine = s.linesIterator.mkString(" ").split(' ')

    lazy val indent = " " * leftOffset

    val output = new StringBuilder(oneLine.head)
    var currentLineWidth = oneLine.head.length
    for(chunk <- oneLine.tail){
      val addedWidth = currentLineWidth + chunk.length + 1
      if (addedWidth > maxWidth){
        output.append("\n" + indent)
        output.append(chunk)
        currentLineWidth = chunk.length
      } else{
        currentLineWidth = addedWidth
        output.append(' ')
        output.append(chunk)
      }
    }
    output.mkString
  }
  def sequenceEither[A, B, M[X] <: TraversableOnce[X]](in: M[Either[A, B]])(
    implicit cbf: CanBuildFrom[M[Either[A, B]], B, M[B]]): Either[A, M[B]] = {
    in.foldLeft[Either[A, mutable.Builder[B, M[B]]]](Right(cbf(in))) {
      case (acc, el) =>
        for (a <- acc; e <- el) yield a += e
    }
      .map(_.result())
  }
}