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kitlangton/parallel-for

Automatically parallelize your for-comprehensions at compile time.
Source code at GitHub null
kitlangton/parallel-for.json
{
  "createdAt": "2022-02-05T04:39:01Z",
  "defaultBranch": "main",
  "description": "Automatically parallelize your for-comprehensions at compile time.",
  "fullName": "kitlangton/parallel-for",
  "homepage": null,
  "language": "Scala",
  "name": "parallel-for",
  "pushedAt": "2024-09-30T14:10:08Z",
  "stargazersCount": 134,
  "topics": [],
  "updatedAt": "2025-11-08T14:34:08Z",
  "url": "https://github.com/kitlangton/parallel-for"
}

Parallel For

Section titled “Parallel For”

[![Release Artifacts][Badge-SonatypeReleases]][Link-SonatypeReleases] [![Snapshot Artifacts][Badge-SonatypeSnapshots]][Link-SonatypeSnapshots]

Automatically parallelize your for comprehensions at compile time.

build.sbt
libraryDependencies ++= Seq(
  "io.github.kitlangton" %% "parallel-for" % "0.0.6",
  "io.github.kitlangton" %% "parallel-for-zio" % "0.0.6", // for ZIO 2
  "io.github.kitlangton" %% "parallel-for-zio1" % "0.0.6", // for ZIO 1
  "io.github.kitlangton" %% "parallel-for-zio-query" % "0.0.6", // for ZIO QUERY (for ZIO 2)
  "io.github.kitlangton" %% "parallel-for-cats-effect-3" % "0.0.6", // for Cats Effect 3
)

Example

Section titled “Example”

Wrapping a for-comprehension in par will automatically parallelize it at compile time.

import parallelfor._
import parallelfor.interop.zio._ // Change this line depending on your effect system
import zio._


val program =
  par {
    for {
      users  <- loadUsers
      files  <- loadFiles
      config <- loadConfig
      result <- process(users, files, config)
      _      <- fireTheMissiles
    } yield result
  }

The par macro will rewrite the above program to—essentially—the following:

val program =
  for {
    (users, files, config, _) <- loadUsers zipPar loadFiles zipPar loadConfig zipPar fireTheMissiles
    result                    <- process(users, files, config)
  } yield result

Neato!

Similar project: [VirtusLab/avocADO] (only for Scala 3)

TODO

Section titled “TODO”
  • Work with ZIO and ZManaged
  • Maximize parallelization with topological sorting
  • Get it to work with val assignments inside of for-comprehensions
  • Set up publishing
  • Generalize to work with any zippable structure (implement against Parallelizable type-class)
  • Fix withFilter interaction
  • Cross-build for JS and Native
  • Cross-build against 2.11/2.12
  • Get it to work with Scala 3

[Badge-SonatypeReleases] !: https://img.shields.io/nexus/r/https/oss.sonatype.org/io.github.kitlangton/parallel-for_2.13.svg “Sonatype Releases” [Badge-SonatypeSnapshots] !: https://img.shields.io/nexus/s/https/oss.sonatype.org/io.github.kitlangton/parallel-for_2.13.svg “Sonatype Snapshots” [Link-SonatypeSnapshots] !: https://oss.sonatype.org/content/repositories/snapshots/io/github/kitlangton/parallel-for_2.13/ “Sonatype Snapshots” [Link-SonatypeReleases] !: https://oss.sonatype.org/content/repositories/releases/io/github/kitlangton/parallel-for_2.13/ “Sonatype Releases” [VirtusLab/avocADO] !: https://github.com/VirtusLab/avocADO