Frist thanks for sharing, some suggestions below:

1. Provides an extension definition for Kotlin ?
2. Provides an extension for Vertx Function?
3. How about keep the Cffu a clean room, and not extends the Future and CompletionStage directly, but provides methods like fromCompletionStage and toCompletionStage.
4. then we can have method like failed instead of failedStage.

目前CompletableFuture提供的都是最多两个入参的方法。

CompletableFuture<Map> future1 = CompletableFuture.supplyAsync(()->{
    Map result = Maps.newHashMap();
    result.put("j","j");
    return result;
});

future1.thenAccept((Map map)->{
    System.out.println("thenAccept:"+map.get("j"));
});

future1.thenCombine(CompletableFuture.completedFuture("123"),(map,s)->{
    System.out.println("thenCombine:"+map.get("j"));
    System.out.println(s);
    return "yy";
});

能否提供操作多个入参的工具类方法？例如多个入参的消费accept，combine

and cool project name 😄

📚 Documentation

🦮 CompletableFuture Guide

• design patterns of biz usage
• best practice and traps
• write English doc, and English first

see README.md

🎪 CompletableFuture Usage Showcase

• timeout control showcase(6386d9b)
• delay execution showcase(6386d9b)

see CompletableFutureUsageShowcaseTest.kt

🇨🇳 Translations

• translate javadoc of
  • CompletableFuture
  • CompletionStage

📦 Library

see

• CffuFactory.java
• Cffu.java

✨ Support the missing convenient new functions

• new methods CffuFactory.cffuAllOf(...)(7acfa4d)
  with results version of CompletableFuture.allof
• new methods CffuFactory.cffuAnyOf(...)(d9df93f)
  type safe version of CompletableFuture.anyOf Method
• new methods Cffu.cffuCombine(...)
  same as CffuFactory.cffuAllOf(...), providing this method is convenient for method chaining.
• new method Cffu.cffuJoin support timeout join ⏳ (323e14a)

🚗 Customizable CF

• sticky default executor for *Async methods

🔮 backport CF functions from high java versions to Java 8

• Cffu.java
  • timeout control methods orTimeout(...)/completeOnTimeout(...)
  • exceptionallyAsync()
  • exceptionallyCompose(...)/exceptionallyComposeAsync(...)
  • resultNow()/exceptionNow()
  • backport Future#state()
    • and add a new method cffuState() to works on Java 8
  • completeAsync(...)
  • minimalCompletionStage()
  • copy()
  • newIncompleteFuture()
• CffuFactory.java
  • delay execution methods defaultExecutor(...)
  • completedStage(...)/failedStage(...)
  • failedFuture(...)

🍩 Kotlin support

• extension methods of java implemented methods

🙌 Mics

• make lib 0-dependence(optional Kotlin runtime is ok)
  implement tuple instead of common-lang3 dependency

☔️ Testing

• API compatibility test with CompletableFuture
  • see CompletableFutureApiCompatibilityTest.java and CffuApiCompatibilityTest.java
• benchmark building chain performance by Cffu vs CompletableFuture
• benchmark execution chain performance by Cffu vs CompletableFuture

👷 Chore

• CI build/Github Action
  • support build by Java 19 and test by low version java(e.g. Java 8) (3a0c8e3)
    because the implementation used high java version api of CF
  • release maven SNAPSHOT to repo when main branch integration_test pass