/**
 * Copyright 2019 Google Inc. All Rights Reserved.
 * 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.
 */ import { Observable } from "../types.js" ; typeparam param os returns export function amb < T > ( ... os ) { return new ReadableStream ( { async start ( controller ) { const readers = os . map ( o => o . getReader ( ) ) ; const reads = readers . map ( async ( r , i ) => [ await r . read ( ) , i ] as const ) ; let [ { value , done } , i ] = await Promise . race ( reads ) ; reads . filter ( ( _ , j ) => j !== i ) . map ( async ( r , j ) => { await r ; readers [ j ] . releaseLock ( ) ; } ) ; const [ fastestObs ] = readers . slice ( i , i + 1 ) ; while ( true ) { if ( done ) { return controller . close ( ) ; } controller . enqueue ( value ! ) ; ( { value , done } = await fastestObs . read ( ) ) ; } } } , { highWaterMark : 0 } ) ; }