> This PR proposes to add a number of "capturing factories" in classes in the > `java.util.function` package. > > The PR additionally (an optionally) proposes to add a new function > `UnaryOperator::andThenUnary` to allow composition while retaining the > `UnaryOperator` type. > > With the new changes, it is possible to write code like this (example from > `java.util.function.Function`): > > > // Resolve ambiguity > var function = Function.of(String::isEmpty); // Function<String, Boolean> > var predicate = Predicate.of(String::isEmpty); // Predicate<String> > > // Fluent composition > var chained = Function.of(String::length) // Function<String, Integer> > .andThen(Integer::byteValue); // Function<String, > Byte> > > > Please see the original bug report for a comprehensive description of these > proposed changes. > > Note: It is not the objective to promote `var` declaration or to prevent > previous ways of capturing lambdas and method references. The comments in the > code above is for explaining the binding and once that becomes obvious, such > comments are likely to not appear in real code. Users that prefers having a > normal type declaration can still do that. > > Note: Functional interfaces of primitives have not been considered (in this > round). Otherwise, functional interfaces that might be ambiguous or that > supports composition have been included. Hence, `Supplier` did not get a > factory method.
Per Minborg has updated the pull request incrementally with one additional commit since the last revision: Add co/contra variance ------------- Changes: - all: https://git.openjdk.org/jdk/pull/16213/files - new: https://git.openjdk.org/jdk/pull/16213/files/dbfb4008..96586f7e Webrevs: - full: https://webrevs.openjdk.org/?repo=jdk&pr=16213&range=01 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=16213&range=00-01 Stats: 34 lines in 7 files changed: 21 ins; 1 del; 12 mod Patch: https://git.openjdk.org/jdk/pull/16213.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/16213/head:pull/16213 PR: https://git.openjdk.org/jdk/pull/16213
