1 files changed, 46 insertions, 0 deletions
diff --git a/core/lib/FiberConversions.scala b/core/lib/FiberConversions.scala
new file mode 100644
index 0000000..fe79796
--- /dev/null
+++ b/core/lib/FiberConversions.scala
@@ -0,0 +1,46 @@
+package eu.mulk.fibers
+
+import scala.collection.generic.CanBuildFrom
+import scala.collection.{GenTraversableOnce, IterableLike}
+import scala.language.implicitConversions
+
+/**
+  * Implicit conversions for convenient use of containers from within
+  * fibers.
+  */
+private[fibers] trait FiberConversions extends FiberTypes {
+  //
+  // This is based on code by James Earl Dougles, taken from:
+  //
+  //     https://earldouglas.com/posts/monadic-continuations.html
+  //
+
+  /**
+    * Defines the `cps` helper on [[IterableLike]] objects, which you can call to
+    * traverse them from fibers.
+    */
+  implicit def cpsIterable[A, Repr](xs: IterableLike[A, Repr]) = new {
+
+    /**
+      * Provides fiber-compatible iteration functions.
+      */
+    def cps = new {
+      def foreach[B, T](f: A => Any @fiber[T]): Unit @fiber[T] = {
+        val it = xs.iterator
+        while (it.hasNext) f(it.next)
+      }
+      def map[B, That, T](f: A => B @fiber[T])(
+          implicit cbf: CanBuildFrom[Repr, B, That]): That @fiber[T] = {
+        val b = cbf(xs.repr)
+        foreach(b += f(_))
+        b.result
+      }
+      def flatMap[B, That, T](f: A => GenTraversableOnce[B] @fiber[T])(
+          implicit cbf: CanBuildFrom[Repr, B, That]): That @fiber[T] = {
+        val b = cbf(xs.repr)
+        for (x <- this) b ++= f(x)
+        b.result
+      }
+    }
+  }
+}