atelier-core

Foundational Effectful-based effects and utilities

https://github.com/tweag/tricorder#readme

Stackage Nightly 2026-08-19:0.4.0.1
Latest on Hackage:0.4.0.1

See all snapshots atelier-core appears in

MIT licensed by Victor Nascimento Bakke
Maintained by [email protected]
This version can be pinned in stack with:atelier-core-0.4.0.1@sha256:01f4e4280bada434e056357cd0b5bd33a714576a509a1448fd11d4bc2ff70b9d,6609

Module documentation for 0.4.0.1

atelier-core

Foundational effects and utilities for effect-based applications, built on Effectful. Part of the atelier toolkit.

Overview

atelier-core provides a set of composable Effectful effects and supporting types for building structured, observable applications.

Module Purpose
Atelier.Component Structured component lifecycle (setup → listeners → start)
Atelier.Config Configuration with environment variable overrides
Atelier.Effects.Log Structured logging with hierarchical namespaces
Atelier.Effects.Conc Thread management via Ki (structured concurrency)
Atelier.Effects.Cache Caching with singleflight deduplication
Atelier.Effects.Publishing Event publishing with context propagation
Atelier.Effects.Monitoring.Tracing OpenTelemetry tracing
Atelier.Effects.Monitoring.Metrics Prometheus metrics
Atelier.Effects.FileWatcher Filesystem change notifications
Atelier.Effects.Process External process management

It also wraps a number of IO-based primitives (environment, clock, file system, console, POSIX) as effects so they can be interpreted and tested explicitly: Atelier.Effects.Env, Atelier.Effects.Clock, Atelier.Effects.FileSystem, Atelier.Effects.Console, Atelier.Effects.Posix.*, and more.

Part of atelier

License

MIT — see LICENSE.

Changes

Changelog

All notable changes to atelier-core will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to the PVP.

[Unreleased]

[0.4.0.1] - 2026-08-14

Removed

  • Dependency on hs-opentemeletry-api for the test suite.

[0.4.0.0] - 2026-08-14

Added

  • Atelier.Effects.Env: lookupEnv picks out a single environment variable.

Changed

  • Major version bump for the following dependencies’ upper version bounds:
    • aeson
    • http-api-data
    • time

Removed

  • Move all metrics and observability tooling to atelier-monitoring:
    • Atelier.Component: moved to atelier-monitoring.
    • Atelier.Effects.Conc.Traced: moved to atelier-monitoring.
    • Atelier.Effects.Monitoring.Metrics: moved to atelier-monitoring.
    • Atelier.Effects.Monitoring.Metrics.Server: moved to atelier-monitoring.
    • Atelier.Effects.Monitoring.Metrics.Registry: moved to atelier-monitoring.
    • Atelier.Effects.Cache.Singleflight: removed tracing capability. Old version with tracing capability is available in atelier-monitoring as Atelier.Effects.Cache.Singleflight.Traced.
    • Atelier.Effects.Publishing#runPubSub: moved to atelier-monitoring in Atelier.Effects.Publishing.Traced.
    • Atelier.Effects.Publshing#runPubSub_: renamed to runPubSub.

[0.3.0.0] - 2026-08-06

Added

  • Atelier.Effects.Process: getExecutablePath returns the absolute path of the currently running executable, for re-invoking the program as a subprocess.
  • Atelier.Effects.Publishing.Pub: map and mapM allows mapping over published effects, producing a new Pub effect with the transformed values.

Changed

  • Moved Pub and Sub out of Atelier.Effects.Publishing to separate modules, Atelier.Effects.Publishing.Pub and Atelier.Effects.Publishing.Sub respectively.

[0.2.0.0] - 2026-06-26

Added

  • Atelier.Effects.File now re-exports IOMode (..).
  • Atelier.Effects.Process: withProcessGroup runs a process in its own process group and guarantees the whole group is torn down when the body returns or throws; terminateProcessGroup aborts a running group from another thread (for children that trap SIGINT, where interrupting the group is not enough).
  • New module Atelier.Effects.Process.Internal, exposing the RunningProcess constructor for tests that fabricate a handle. Production code should not import it.

Changed

  • Breaking: Atelier.Effects.Process.RunningProcess is now a distinct newtype wrapping System.Process.Typed.Process (previously a type synonym). getStdin/getStdout/getStderr operate on the new type.

Removed

  • Breaking: Atelier.Effects.Process no longer exports setCreateGroup, startProcess, or stopProcess. Process lifecycle is now managed through withProcessGroup.

[0.1.0.0] - 2026-06-05

Added

  • Initial release: foundational Effectful-based effects and utilities, extracted from the atelier toolkit.