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POScala implementation of C#-like yield with "for"
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copied!<p>I'm trying to use various Scala implementations of C#-like yield return (i.e. <a href="https://stackoverflow.com/questions/2201882/implementing-yield-yield-return-using-scala-continuations/2215182" title="this implementation">this one</a>) with "for" -constructions such as:</p> <pre><code>private def permutations[T](s: Vector[T]) = { def swap(i: Int, j: Int) { val tmp = s(i) s.set(i, s.get(j)) s.set(j, tmp) } iterator[Vector[T]] { def generate(left: Int, right: Int): Unit @cps[Iteration[Vector[T]]] = { if (left >= right) yieldValue(s) else { generate(left, right) for (i <- left to right) { swap(left, i) generate(left+1, right) swap(left, i) } } } generate(0, s.size-1) } } </code></pre> <p>But this code compiles with error: </p> <pre><code>error: no type parameters for method foreach: (f: (Int) => U)Unit exist so that it can be applied to arguments ((Int) => Unit @util.continuations.package.cps[ru.ispras.texterra.nlp.GHMMDisambiguator.Iteration[Vector[T]]]) --- because --- argument expression's type is not compatible with formal parameter type; found : (Int) => Unit @util.continuations.package.cps[ru.ispras.texterra.nlp.GHMMDisambiguator.Iteration[Vector[T]]] required: (Int) => ?U for (i <- left to right) { </code></pre> <p>As I understand I have to make all code inside for to be type of <code>() => Unit</code>, not of <code>() => Unit @with-annotations</code>. How can I do that?</p> <p>This problem seems to be very common, but I didn't found any mentions in the Internet.</p>

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