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Pure functional JDBC layer for Scala.

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package doobie.util

import cats.{ Applicative, Functor }
import cats.implicits._
import fs2.{ Stream => Process, Sink }
import fs2.Stream.{ attemptEval, fail, emits, empty }

/** Additional functions for manipulating `Process` values. */
object process {

  /** Generalized `sink` constructor. */
  def sink[F[_]: Applicative, A](f: A => F[Unit]): Sink[F, A] =
    _.flatMap(a => Process.eval(f(a)))

  /** Stream constructor for effectful source of chunks. */
  def repeatEvalChunks[F[_], T](fa: F[Seq[T]]): Process[F, T] = 
    attemptEval(fa) flatMap {
      case Left(e)    => fail(e)
      case Right(seq) => if (seq.isEmpty) empty else (emits(seq) ++ repeatEvalChunks(fa))
    }

}