Changes for version v0.1.1 - 2026-11-08
- The pipeline from DBIx-Squirrel v2.0.2, on its own, so that any function can take stages from its caller.
- It ships three roadmap items, settled after v0.1.0's trial: a pipeline's stages can be spliced into another, with the stages method (2026-0001); an iterator ends once a stage dies (2026-0002); and a pipeline's count in scalar context is promised (2026-0003).
- Requires Perl 5.36 or later.
- Ekorn::Pipeline runs values through a list of stages, each a code reference given one value, in $_ and as its argument, and returning nothing (a filter), one value (a map) or several (a flatMap). A pipeline is called with values, or pulls them from a source with an iterator, calling it only as results are wanted.
- Once a stage dies, an iterator has ended, as a pushed run has: every call after returns an empty list, and neither the source nor any end function is called again. In v0.1.0's trial it carried on, without the value that died. (roadmap 2026-0002)
- Called in scalar context, a pipeline returns how many results came out, as an array would; the POD now promises it. (roadmap 2026-0003)
- A pipeline's stages method returns its stages, so they can be spliced into another pipeline, or given to any function that takes stages, running as if listed there. (roadmap 2026-0001)
- SECURITY.md says how to report a vulnerability, privately, and CONTRIBUTING.md how to report a bug or ask for a feature; the distribution takes issues, not pull requests.
- Ekorn::Pipeline::Stop ends a pipeline early, passing on any values it carries, after which the source isn't called again. A stop not made by throw, and so not an array, carries nothing.
- Ekorn::Pipeline::Gather makes a stage afresh for each run, with an optional end function, called once the values run out.
- Ekorn::Pipeline::Pipes gives a class pipe and tap methods, which run the object through stages.
- Canned stages: take, drop, take_while and drop_while in Ekorn::Pipeline::Stages::Flow; batch and collect in Ekorn::Pipeline::Stages::Batch; peek, count_into and dump_to in Ekorn::Pipeline::Stages::Taps.
- A stage that dies is named by its place, at the caller's line, and so are mistakes in making a pipeline or a canned stage.
- Modules of stages can live under any namespace: general stages under Ekorn::Pipeline::Stages, and those for one kind of value or source with the module that knows about it, built from Gather, Stop and croakf, which reports at the caller's line.
- Versions: a v0.1.x only fixes or adds. A change to how stages behave, or a public name dropped or renamed, waits for v0.2.0.
- A how-to, docs/HOWTO.md, with recipes for callers, function authors and stage authors, and a reference, docs/REFERENCE.md, describing every module and how a pipeline behaves, with notes for stage authors. Both are on GitHub, linked from the README.
Modules
run values through a list of stages
report Ekorn::Pipeline's errors at the caller's line
a stage made afresh for each run, told when the values run out
pipe and tap methods, running an object through stages
stages gathering values: batch and collect
stages taking or dropping values: take, drop, take_while and drop_while
stages run for their side effects: peek, count_into and dump_to
end a pipeline early