codeconsole opened a new pull request, #3256: URL: https://github.com/apache/groovy/pull/3256
https://issues.apache.org/jira/browse/GROOVY-12722 `sumParallel(Collection<T>, BinaryOperator<T>)` is a reduction with a required two-argument combiner, where `sum()` adds the elements and `sum(Closure)` adds their transforms. Code written by analogy with `sum` failed: `items.sumParallel { it.price }` called the one-parameter closure with two arguments, and under static compilation was rejected with "Wrong number of parameters for method target: apply(java.lang.Integer, java.lang.Integer)". That is the form a model with the parallel-collections documentation in front of it still wrote. Two additive forms in `ParallelCollectionExtensions`: - `sumParallel(Collection<?> self)` adds the elements with the left operand's `plus`, as `sum()` does; an empty collection gives `null`. - `<T, R> R sumParallel(Collection<T> self, Closure<R> closure)`, with `@ClosureParams(value = FromString, options = ["T", "T,T"])`: a one-parameter closure is a transform whose results are added; a two-parameter closure is the combiner of the `BinaryOperator` form, so existing calls keep working and, under static compilation, keep their result type (`int combined = numbers.sumParallel { int a, int b -> a + b }`). The `BinaryOperator` overload stays for method references and Java callers. `CombinerChecker` leaves a one-parameter closure passed to `sumParallel` alone: it is a transform, not a combiner. `core-parallel-collections.adoc` and the GPars migration table show the three forms. Tests: `ParallelCollectionTest.testSumParallelAddsUpLikeSum` (numbers, decimals, strings, lists, empty and one-element collections, the transform, the combiner, a method reference, and the three forms under `@CompileStatic`), `CombinerCheckerTest.transform_closure_is_not_a_combiner` (strict mode). Also run locally: `groovy.concurrent.ParallelCollectionTest`, `DesignPatternsTest`, `ParallelExecutorTasksTest` and `CombinerCheckerTest`, 134 tests, passing. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
