fun -- Core Library for Go Programming

fun is a simple, well-tested, zero-dependency "Core Library" for Go. Think of it as a collection of the best parts of the utils package or shared or common packages in any given Go application, but with solid design, highly ergonomic interfaces, and thorough testing.

fun aims to be easy to adopt: the interfaces (and implementations!) are simple and (hopefully!) easy to use. There are no external dependencies and all of the code is well-tested. You can (and should!) always adopt the tools that make the most sense to use for your project.

Highlights

• Every iterator tool you always wish you had in the irt (ha!) package. Easily create, manipulate, and transform iterators, and avoid writing (and rewriting,) basic logic again and again.

• Error tools. erc.Collector is an error aggregator safe for concurrent access, with methods to collect errors conditionally (for validation), and annotating errors. The ers collection has a string-derived error type ers.Error so that you can have const errors.

• A set of worker pools helpers and tools in the wpa package for both ephemeral workloads as well as long-running pipelines. Particularly powerful in combination with the data types, iterator tools, and pubsub tooling.

• Powerful synchronization and atomic primitives, updated for the era of generics in adt:

  • adt.Map[K,V] means now you can use sync.Map without (terrifying) type casts everywhere.

  • adt.Pool[T] provides a type-safe sync.Pool with cleanup and constructor hooks.

  • adt.Atomic[T] is an atomic value container, that you can use to avoid littering your code with mutexes. (n.b. you can store mutable atomic values in adt.Atomic[T] which are (of course) not safe for concurrent use, which is a bit of a gotcha, but for this adt.Locked[T] steps in to handle the mutex for you.

  • adt.Once[T] means you can get sync.OnceFunc, and friends, but as a type that you can add as a field to your on types for mutexes that you don't have to manage yourself.

  • within adt, shard.Map[K,V] provides a write-optimized, fully versioned map implementation that divides the keyspace among a number of constituent maps (shards) to reduce mutex contention for certain workloads.

• Delightful data types you always wish you had, in the dt package:

  • a ring buffer (dt.Ring[T])
  • single and doubly linked lists (dt.Stack[T] and dt.List[T])
  • sets (dt.Set[K] and dt.OrderedSet[T])
  • an ordered map dt.OrderedMap[K,V] (also thread safe, and accessible via adt.)
  • histograms (in dt/hdrhist)
  • wrappers of standard library (stw)things (maps, slices, pointers,) for ergonomic takes on Go constructs.
  • an "optional" wrapper (dt.Optional[T]) so you can avoid overloading pointer values in your type definitions.

• A collection of function object tools, wrappers and tools for common function type in fn (without contexts) and fnx (with contexts).

• Higher order pubsub tools, notably threadsafe queue and deque implementations--pubsub.Queue[T] and pubsub.Deque[T] which avoid channels entirely, and have support for unlimited, fixed-buffered, and burstable limits. Also a one-to-many or a many-to-many message broker, so you can have a "broadcast channel."

• Service orchestration. srv.Service handles the lifecycle of "background" processes inside of an application. You can now start services like HTTP servers, background monitoring and workloads, and sub-processes, and ensure that they exit cleanly (at the right time!) and that their errors propagate clearly back to the "main" thread.

• Lightweight test infrastructure: assert and check (testify-style assertions, but with generics,) testing tools and helpers in testt (testy!), and a fluent-style interface with ensure.

Version History

There are no plans for a 1.0 release, though major backward-breaking changes increment the second (major) release value, and limited maintenance releases are possible/considered to maintain compatibility.

• v0.14.0: go1.24 and greater. Re-focus API; new irt and wpa packages. Move all code out of the root package. (current)
• v0.13.0: go1.24 and greater. Reorganization of function API, and a bridge to the next major release. (experimental)
• v0.12.0: go1.24 and greater. Major API impacting release. (maintained)
• v0.11.0: go1.23 and greater.
• v0.10.0: go1.20 and greater.
• v0.9.0: go1.19 and greater.

There may be small changes to exported APIs within a release series, although, major API changes will increment the major release value.

Contribution

Contributions welcome, the general goals of the project:

• superior API ergonomics.
• great high-level abstractions.
• obvious and clear implementations.
• no external dependencies.

Please feel free to open issues or file pull requests.

Have fun!