Go Source code for UnMango

A collection of random Go packages.

iter

The iter package builds on the standard iter package. It re-exports Seq and Seq2 for convenience and adds Seq3. It adds sequence creation functions such as Empty, Singleton, and Values.

var seq Seq[int] = iter.Empty[int]()
var seq Seq[int] = iter.Singleton(69)
var seq Seq[int] = iter.Values(69, 420)

It also adds various sequence operations such as Map, Fold, and Filter.

var seq Seq[int] = iter.Values(69, 420)

// [70, 421]
mapped := iter.Map(seq, func(i int) int {
	return i + 1
})

// 489
sum := iter.Fold(seq, func(acc, i int) {
	return acc + i
}, 0)

// [69]
filtered := iter.Filter(seq, func(i int) bool {
	return i != 420
})

maps

Primarily re-exports functions and types for convenience. Due to Go not currently supporting generic type aliases, these functions adapt the standard iter seq to this module's iter package.

func Test(seq iter.Seq2[string, int]) {
	var m map[string]int = maps.Collect(seq)
}

The maps package also adds AppendSeq for appending a map to a Seq2.

seq := maps.All(map[string]string{"foo": "bar"})

// {"foo": "bar", "bin": "baz"}
seq = maps.AppendSeq(seq, map[string]string{"bin": "baz"})

result

The result pakcage adds the Result type representing either success or error. It also adds various result operations such as Map and Bind.

func main() {
	var r Result[int] = func() (int, error) {
		return 420, nil
	}

	r = result.Map(r, func(x int) int {
		return x+1
	})
}

slices

The slices package re-exports functions and types from the standard slices package for convenience. Due to Go not currently supporting generic type aliases, these functions adapt the standard slices seq to this module's slices package.

rx

The rx package attempts to implement the observable and signal patterns for reactive programming in go. Both observable and signal should be considered a 🚧 work in progress 🚧, but the observable package is generally usable.

var obs rx.Observable[int] = subject.New[int]()

sub := obs.Subscribe(observer.Lift(func(i int) {
	fmt.Println(i)
}))
defer sub()

obs.OnNext(69)
obs.OnComplete()

Inspiration

I stand on the shoulders of giants. A lot of this is inspired by the works of others, be sure to check out these repos as well. (They're much smarter than me)

https://github.com/fogfish/golem

• A Guide to Pure Combinators in Golang

https://github.com/IBM/fp-go