java.util extensions

Table of Contents

• Functional extensions
• Collections
• Release history

Functional extensions

Classes related to java.util.Function and extensions like Predicate, Consumer and Supplier.

• TriFunction, QuadriFunction

• TriConsumer

• TriPredicate

• Morphing methods like

  • TriFunction#ignoreArg[1-4](…​) morphs a TriFunction to a QuadriFunction

  • TriFunction#withArg[1-3](…​) morphs a TriFunction to a BiFunction.

• Utilities for that in

  • Functions

  • Consumers

  • Predicates,

  • Suppliers

    Things like memoize (to memoize the value of a supplier), closeable (to make a Supplier AutoCloseable) and ignoreArg (to morph a Supplier to a Function that ignores the argument) are provided.

• Consistent equals and hashCode, for the utility functions that produce functional implementations. E.g. the above mentioned ignoreArg* and withArg* are not simply implemented with lambda’s, but also with equals and hashcode based on the source functional class implementation.

Collections

Release history

Version	date	remarks 1.18
2026-08	Having collection module too.	1.17
2026-03	For the 'Throwing-' functional interfaces, there are now also overridden verison of the 'withArgN' and 'ignoreArgN' morphing methods, that remain 'Throwing-' functional interfaces, and throw the same exception as the original functional interface.	1.12
2025-06-26	A.o, introduction of 'CloseableSupplier' and 'UnwrappableSupplier' interfaces,	1.11
2024-05-11		1.10
2023-12		1.0