@lightbend/akkaserverless-javascript-sdk/src/replicated-data/iterators.js

Akka Serverless JavaScript SDK

/*
 * Copyright 2021 Lightbend Inc.
 *
 * 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.
 */

// Internal utility functions for iterators

// Map an iterator to a new iterator
function map(iter, f) {
  const mapped = {
    [Symbol.iterator]: () => mapped,
    next: () => {
      const next = iter.next();
      if (next.done) {
        return {
          done: true,
        };
      } else {
        return {
          value: f(next.value),
          done: false,
        };
      }
    },
  };
  return mapped;
}

module.exports = {
  map: map,
};