gonads

Warning

This library uses Go 1.27rc1 for generic methods, which is not a stable release

A minimal library for monadic types and functional list abstractions, leveraging Go 1.27 generics.

Design:

• Small footprint, favoring composable types and methods
• "Dot import" friendly, only provides constructors and a few utilities in the namespace
• Chainable methods provide type operations

Features

All types have safe accessors, and map/filter/fold methods.

• Option[T] - Some/None type
  • Some: Value is present and accessible
  • None: no value, must be handled
• Result[T] - Ok/Error type
  • Ok: Value is present and accessible
  • Err: Error encountered, must be handled
• List[T] - Slice with functional helpers

Quick Start

foo := PackResult(ThingThatCanError()).
    Map(func(x int) int { return x * 2 }).
    Fold(
        func(x int) string { return fmt.Sprintf("Value: %v", x) },
        func(e error) string { return fmt.Sprintf("Uh Oh... [%v]", e) },
    )

fmt.Println(foo)

func isEven(x int) bool {
	return x%2 == 0
}

func main() {
	evens := List[int]{1, 2, 3, 4, 5, 6, 7}.Filter(isEven)

	first := evens.First()
	count := len(evens)
	avg := evens.Reduce(func(a int, b int) int { return a + b }, 0) / count

	if first.IsSome() {
		fmt.Printf("First Even: %v\n", first.Get())
		fmt.Printf("Num Evens: %v\n", count)
		fmt.Printf("Avg of evens: %v\n", avg)
	} else {
		fmt.Printf("No evens...")
	}
}

Installation

go get github.com/FreeSamples00/gonads

Importing

Dot Import

Recommended for top level Ok() style constructors.

import (
    . "github.com/FreeSamples00/gonads"
)

Import

import "github.com/FreeSamples00/gonads"

API Reference

Full documentation is available here.