book

You Don't Know JS: Async & Performance

by Kyle Simpson

February 2015

Intermediate to advanced

296 pages

5h 48m

English

O'Reilly Media, Inc.

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MissionReviewConventions Used in This BookUsing Code ExamplesSafari® Books OnlineHow to Contact Us
A Program in ChunksAsync ConsoleEvent LoopParallel ThreadingRun-to-CompletionConcurrencyNoninteractingInteractionCooperationJobsStatement OrderingReview
ContinuationsSequential BrainDoing Versus PlanningNested/Chained CallbacksTrust IssuesTale of Five CallbacksNot Just Others’ CodeTrying to Save CallbacksReview
What Is a Promise?Future ValueCompletion EventThenable Duck TypingPromise TrustCalling Too EarlyCalling Too LateNever Calling the CallbackCalling Too Few or Too Many TimesFailing to Pass Along Any Parameters/EnvironmentSwallowing Any Errors/ExceptionsTrustable Promise?Trust BuiltChain FlowTerminology: Resolve, Fulfill, and RejectError HandlingPit of DespairUncaught HandlingPit of SuccessPromise PatternsPromise.all([ .. ])Promise.race([ .. ])Variations on all([ .. ]) and race([ .. ])Concurrent IterationsPromise API Recapnew Promise(..) ConstructorPromise.resolve(..) and Promise.reject(..)then(..) and catch(..)Promise.all([ .. ]) and Promise.race([ .. ])Promise LimitationsSequence Error HandlingSingle ValueSingle ResolutionInertiaPromise UncancelablePromise PerformanceReview
Breaking Run-to-CompletionInput and OutputMultiple IteratorsGenerator-ing ValuesProducers and IteratorsIterablesGenerator IteratorIterating Generators AsynchronouslySynchronous Error HandlingGenerators + PromisesPromise-Aware Generator RunnerPromise Concurrency in GeneratorsGenerator DelegationWhy Delegation?Delegating MessagesDelegating AsynchronyDelegating RecursionGenerator ConcurrencyThunkss/promise/thunk/Pre-ES6 GeneratorsManual TransformationAutomatic TranspilationReview
Web WorkersWorker EnvironmentData TransferShared WorkersPolyfilling Web WorkersSIMDasm.jsHow to Optimize with asm.jsasm.js ModulesReview
BenchmarkingRepetitionBenchmark.jsContext Is KingEngine OptimizationsjsPerf.comSanity CheckWriting Good TestsMicroperformanceNot All Engines Are AlikeBig PictureTail Call Optimization (TCO)Review
Sequences and Abstraction Designasynquence APIStepsErrorsParallel StepsForking SequencesCombining SequencesValue and Error SequencesPromises and CallbacksIterable SequencesRunning GeneratorsWrapped GeneratorsReview
Iterable SequencesExtending Iterable SequencesEvent ReactiveES7 ObservablesReactive SequencesGenerator CoroutineState MachinesCommunicating Sequential Processes (CSP)Message Passingasynquence CSP emulationReview

Overview

No matter how much experience you have with JavaScript, odds are you don’t fully understand the language. As part of the "You Don’t Know JS" series, this concise yet in-depth guide focuses on new asynchronous features and performance techniques—including Promises, generators, and Web Workers—that let you create sophisticated single-page web applications and escape callback hell in the process.