Rename map to rewrite.

Reviewers: O4 Material Apple platform reviewers, #material_motion, O2 Material Motion, appsforartists

Reviewed By: #material_motion, O2 Material Motion, appsforartists

Tags: #material_motion

Differential Revision: http://codereview.cc/D2527

examples/SwipeExample.swift

@@ -59,15 +59,15 @@ class TossableStackedCard: Interaction {
                  whenAbove: TossDirection.right),
                   to: tossDirection)
 
-    let destinationStream = tossDirection.map([
+    let destinationStream = tossDirection.rewrite([
       .none: containerView.bounds.midX,
       .left: -view.bounds.width,
       .right: containerView.bounds.width + view.bounds.width
       ]
     )
     runtime.write(destinationStream, to: attachment.spring.destination)
 
-    let gestureEnabledStream = tossDirection.map([
+    let gestureEnabledStream = tossDirection.rewrite([
       .none: true,
       .left: false,
       .right: false

src/operators/map.swift → src/operators/rewrite.swift

@@ -19,7 +19,7 @@ import Foundation
 extension ExtendableMotionObservable where T: Hashable {
 
   /** Emits the mapped value for each incoming value, if one exists, otherwise emits nothing. */
-  public func map<U>(_ values: [T: U]) -> MotionObservable<U> {
+  public func rewrite<U>(_ values: [T: U]) -> MotionObservable<U> {
     return _nextOperator { value, next in
       if let mappedValue = values[value] {
         next(mappedValue)