fm.common.rich.RichMap.scala Maven / Gradle / Ivy

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/*
 * Copyright 2014 Frugal Mechanic (http://frugalmechanic.com)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package fm.common.rich

import scala.collection.generic.CanBuildFrom
import scala.collection.MapLike
import scala.collection.immutable.SortedMap

final class RichMap[A, B, This <: MapLike[A,B,This] with scala.collection.Map[A,B]](val self: MapLike[A,B,This]) extends AnyVal {
  /**
   * The normal Map.mapValues method produces a view which is not what we usually want.
   * This is a strict version of it.
   * 
   * https://issues.scala-lang.org/browse/SI-4776
   */
  // TODO: figure out how to make the CanBuildFrom stuff actually work so you end up with the same Map type that you started with
  @inline def mapValuesStrict[C, That <: scala.collection.Map[A, C]](f: B => C)(implicit bf: CanBuildFrom[This, (A, C), That]): That = self.map{ case (k,v) => (k, f(v)) }
  
  def toSortedMap(implicit ord: Ordering[A]): SortedMap[A, B] = self match {
    case sorted: SortedMap[_,_] => sorted.asInstanceOf[SortedMap[A,B]]
    case _ =>
      val builder = SortedMap.newBuilder[A,B]
      builder ++= self
      builder.result
  }
  
  def toReverseSortedMap(implicit ord: Ordering[A]): SortedMap[A, B] = toSortedMap(ord.reverse)
}