Closes #163

aloha-cli/src/test/scala/com/eharmony/aloha/cli/ModelTypesTest.scala

@@ -28,6 +28,7 @@ class ModelTypesTest {
       "ModelDecisionTree",
       "Regression",
       "Segmentation",
+      "SparseMultilabel",
       "VwJNI"
     )
 

aloha-core/src/main/scala/com/eharmony/aloha/dataset/StatefulRowCreator.scala

@@ -0,0 +1,76 @@
+package com.eharmony.aloha.dataset
+
+import com.eharmony.aloha.util.StatefulMapOps
+
+import scala.collection.{SeqLike, immutable => sci}
+import scala.collection.generic.{CanBuildFrom => CBF}
+
+/**
+  * A row creator that requires state.  This state should be modeled functionally, meaning
+  * implementations should be referentially transparent.
+  *
+  * Created by ryan.deak on 11/2/17.
+  */
+trait StatefulRowCreator[-A, +B, S] extends Serializable {
+
+  /**
+    * Some initial state that can be used on the very first call to `apply(A, S)`.
+    * @return some state.
+    */
+  val initialState: S
+
+  /**
+    * Given an `a` and some `state`, produce output, including a new state.
+    *
+    * When using this function, the user is responsible for keeping track of,
+    * and providing the state.
+    *
+    * The implementation of this function should be referentially transparent.
+    *
+    * @param a input
+    * @param state the state
+    * @return a tuple where the first element is a Tuple2 whose first element is
+    *         missing and error information and second element is an optional result.
+    *         The second element of the outer Tuple2 is the new state.
+    */
+  def apply(a: A, state: S): ((MissingAndErroneousFeatureInfo, Option[B]), S)
+
+  /**
+    * Apply the `apply(A, S)` method to the elements of the iterator.  In the first
+    * application of `apply(A, S)`, `state` will be used as the state.  In subsequent
+    * applications, the state will come from the state generated in the output of the
+    * previous application of `apply(A, S)`.
+    *
+    * For more information, see [[com.eharmony.aloha.util.StatefulMapOps]]
+    *
+    * @param as Note the first element of `as` ''will be forced'' in this method in order
+    *           to construct the output.
+    * @param state the initial state to use at the start of the iterator.
+    * @return an iterator containing the `a` mapped to a
+    *         `(MissingAndErroneousFeatureInfo, Option[B])` along with the resulting
+    *         state that is created in the process.
+    */
+  def statefulMap(as: Iterator[A], state: S): Iterator[((MissingAndErroneousFeatureInfo, Option[B]), S)] =
+    StatefulMapOps.statefulMap(as, state)(apply)
+
+  /**
+    * Apply the `apply(A, S)` method to the elements of the sequence.  In the first
+    * application of `apply(A, S)`, `state` will be used as the state.  In subsequent
+    * applications, the state will come from the state generated in the output of the
+    * previous application of `apply(A, S)`.
+    *
+    * '''NOTE''': This method isn't really parallelizable via chunking.  The way to
+    * parallelize this method is to provide a separate starting state for each unit
+    * of parallelism.
+    *
+    * For more information, see [[com.eharmony.aloha.util.StatefulMapOps]]
+    *
+    * @param as input to map.
+    * @param state the initial state to use at the start of mapping.
+    * @param cbf object responsible for building the output collection.
+    * @return 
+    */
+  def statefulMap[In <: sci.Seq[A], Out](as: SeqLike[A, In], state: S)(implicit
+      cbf: CBF[In, ((MissingAndErroneousFeatureInfo, Option[B]), S), Out]
+  ): Out = StatefulMapOps.statefulMap(as, state)(apply)
+}

aloha-core/src/main/scala/com/eharmony/aloha/dataset/StatefulRowCreatorProducer.scala

@@ -0,0 +1,43 @@
+package com.eharmony.aloha.dataset
+
+import com.eharmony.aloha.semantics.compiled.CompiledSemantics
+import spray.json.JsValue
+
+import scala.util.Try
+
+/**
+  * Created by deaktator on 11/6/17.
+  *
+  * @tparam A
+  * @tparam B
+  * @tparam S
+  * @tparam Impl
+  */
+trait StatefulRowCreatorProducer[A, +B, S, +Impl <: StatefulRowCreator[A, B, S]] {
+
+  /**
+    * Type of parsed JSON object.
+    */
+  type JsonType
+
+  /**
+    * Name of this producer.
+    * @return
+    */
+  def name: String
+
+  /**
+    * Attempt to parse the JSON AST to an intermediate representation that is used
+    * @param json
+    * @return
+    */
+  def parse(json: JsValue): Try[JsonType]
+
+  /**
+    * Attempt to produce a Spec.
+    * @param semantics semantics used to make sense of the features in the JsonSpec
+    * @param jsonSpec a JSON specification to transform into a StatefulRowCreator.
+    * @return
+    */
+  def getRowCreator(semantics: CompiledSemantics[A], jsonSpec: JsonType): Try[Impl]
+}

aloha-core/src/main/scala/com/eharmony/aloha/dataset/vw/multilabel/PositiveLabelsFunction.scala

@@ -0,0 +1,42 @@
+package com.eharmony.aloha.dataset.vw.multilabel
+
+import com.eharmony.aloha.AlohaException
+import com.eharmony.aloha.dataset.DvProducer
+import com.eharmony.aloha.dataset.vw.multilabel.VwMultilabelRowCreator.{determineLabelNamespaces, LabelNamespaces}
+import com.eharmony.aloha.reflect.RefInfo
+import com.eharmony.aloha.semantics.compiled.CompiledSemantics
+import com.eharmony.aloha.semantics.func.GenAggFunc
+
+import scala.collection.breakOut
+import scala.util.{Failure, Success, Try}
+import scala.collection.{immutable => sci}
+
+/**
+  * Created by ryan.deak on 11/6/17.
+  * @param ev$1
+  * @tparam A
+  * @tparam K
+  */
+private[multilabel] abstract class PositiveLabelsFunction[A, K: RefInfo] { self: DvProducer =>
+
+  private[multilabel] def positiveLabelsFn(
+      semantics: CompiledSemantics[A],
+      positiveLabels: String
+  ): Try[GenAggFunc[A, sci.IndexedSeq[K]]] =
+    getDv[A, sci.IndexedSeq[K]](
+      semantics, "positiveLabels", Option(positiveLabels), Option(Vector.empty[K]))
+
+  private[multilabel] def labelNamespaces(nss: List[(String, List[Int])]): Try[LabelNamespaces] = {
+    val nsNames: Set[String] = nss.map(_._1)(breakOut)
+    determineLabelNamespaces(nsNames) match {
+      case Some(ns) => Success(ns)
+
+      // If there are so many VW namespaces that all available Unicode characters are taken,
+      // then a memory error will probably already have occurred.
+      case None => Failure(new AlohaException(
+        "Could not find any Unicode characters to as VW namespaces. Namespaces provided: " +
+          nsNames.mkString(", ")
+      ))
+    }
+  }
+}