go-functional

Functional programming primitives and OTP-inspired concurrency patterns for Go generics.

Installation

go get github.com/mikehelmick/go-functional

Requires Go 1.24+.

Packages at a glance

Functional primitives

Package	Highlights
`slice`	Filter, Map, Fold, Find, Zip, Chunk, Sort, Dedup, Scan, Frequencies
`maps`	MapValues, FilterMap, Merge, MergeWith, Invert
`optional`	`Maybe[T]` — Some or None
`result`	`Result[T]` — chainable error handling
`pipeline`	Function composition: `Pipe`, `Pipe2`, `Pipe3`, `Pipe4`

OTP-inspired concurrency

Package	Highlights
`agent`	Goroutine-owned mutable state
`genserver`	Serialised request/response loop
`task`	Typed async work with `Await` / `AwaitAll`
`supervisor`	Automatic goroutine restart (`OneForOne` / `OneForAll`)

Quick look

// Concurrent document processing with OTP building blocks
freqs := agent.New(map[string]int{})

tasks := slice.Map(docs, func(doc string) *task.Task[map[string]int] {
    return task.Run(func() (map[string]int, error) {
        return slice.Frequencies(strings.Fields(doc)), nil
    })
})

results, _ := task.AwaitAll(tasks)
for _, r := range results {
    freqs.Update(func(cur map[string]int) map[string]int {
        for word, n := range r { cur[word] += n }
        return cur
    })
}

See the example application for the full OTP-style word frequency service.