option

Option[T] for values that may be absent.

Rust API in Go

This is a wlrgo package. wlrgo ports Rust standard-library types to Go and intentionally copies the Rust API instead of reshaping it into an idiomatic Go design. Later packages in the org follow the same rule.

Names, combinators, and eager vs lazy evaluation follow std::option::Option as closely as Go generics allow. A few Go-only helpers exist where Rust has no equivalent: Get, FromOK, FromPtr, Ptr, and OkOr.

Install

Requires Go 1.27 or later.

go get github.com/wlrgo/option/v2

Example

package main

import (
	"fmt"
	"strconv"

	"github.com/wlrgo/option/v2"
)

func main() {
	opt := option.FromOK(strconv.Atoi("2"))
	if v, ok := opt.Get(); ok {
		fmt.Println(v)
	}

	fmt.Println(opt.Map(func(n int) int { return n * 10 }).UnwrapOr(-1))
}

The zero value is None. Some and None construct an option; FromOK and FromPtr convert from (T, error) and *T. Combinators such as Map, And, and Or are methods. Compare, Flatten, and Collect remain package-level functions.

API

Group	Highlights
Query	IsSome, IsNone, IsSomeAnd, IsNoneOr
Extract	Unwrap, Expect, UnwrapOr, Get
Combine	And, AndThen, Or, OrElse, Xor
Transform	Map, Filter, Flatten, ZipWith, Reduce
Compare	Compare, Equal (None < Some)
Modify	Insert, Take, TakeIf, Replace
Iterate	Seq, Collect
Convert	FromOK, FromPtr, Ptr, OkOr

See pkg.go.dev/github.com/wlrgo/option/v2 for the full API and package contract.

License

MIT