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Play Framework/Scala example source code file (Collections.scala)
The Collections.scala Play Framework example source code/* * Copyright (C) 2009-2013 Typesafe Inc. <http://www.typesafe.com> */ package play.api.libs /** * Utilities functions for Collections */ object Collections { /** * Produces a Seq from a seed and a function. * * Example, produces a List from 0 to 100. * * {{{ * unfoldLeft(0) { state match * case a if a > 100 => None * case a => (a + 1, a + 1) * } * }}} * * @tparam A Type of the final List elements. * @tparam B Seed type * @param seed Initial value. * @param f Function producing the List elements. */ def unfoldLeft[A, B](seed: B)(f: B => Option[(B, A)]): Seq[A] = { def loop(seed: B)(ls: List[A]): List[A] = f(seed) match { case Some((b, a)) => loop(b)(a :: ls) case None => ls } loop(seed)(Nil) } } Other Play Framework source code examplesHere is a short list of links related to this Play Framework Collections.scala source code file: |
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