async

README

Async

Run async code with safe!

Example

package main

import (
	"context"
	"fmt"

	"github.com/WinPooh32/async"
)

func main() {
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	fn := func(ch chan<- async.Option[string]) error {
		err := async.TrySend(ctx, ch, "Hello Async!")
		if err != nil {
			return err
		}

		return nil
	}

	ch := async.Go(ctx, fn)

	value, err := async.Await(ctx, ch)
	if err != nil {
		panic(err)
	}

	fmt.Println(value)
}

Look for more examples at async_test.go

Documentation

Index

• Variables
• func Await[T any](ctx context.Context, ch <-chan Option[T]) (value T, err error)
• func Go[T any](ctx context.Context, f Func[T], capacity ...int) <-chan Option[T]
• func Group[T any](ctx context.Context, g func(i int) Func[T], n int, capacity ...int) <-chan Option[T]
• func TrySend[T any](ctx context.Context, ch chan<- Option[T], value T) (err error)
• func TrySendError[T any](ctx context.Context, ch chan<- Option[T], err error) (_ error)
• func With(ctx context.Context, opt ...OptFunc) (context.Context, context.CancelFunc)
• type Func
• type OptFunc
  • func Wait() OptFunc
• type Option
  • func MakeErr[T any](err error) Option[T]
  • func MakeValue[T any](v T) Option[T]
  • func (opt Option[T]) Err() error
  • func (opt Option[T]) Value() T

Variables

var ErrChannelClosed = errors.New("channel is closed")

Functions

func Await

func Await[T any](ctx context.Context, ch <-chan Option[T]) (value T, err error)

Await reads channel ch and unwraps option to value and error. Can be interrupted by closed context.

func Go

func Go[T any](ctx context.Context, f Func[T], capacity ...int) <-chan Option[T]

Go safely runs function f at a new goroutine. The ch channel will be closed automatically after f returns. If panic occurs inside of f it will be recovered and error will be written to the ch channel. If capacity is defined or greater than zero, buffered channel will be created.

func Group

func Group[T any](ctx context.Context, g func(i int) Func[T], n int, capacity ...int) <-chan Option[T]

Group runs g(i) functions in parallel, their output falls into one channel. n is a count of passed functions. i is ranged from 0 to n-1.

func TrySend

func TrySend[T any](ctx context.Context, ch chan<- Option[T], value T) (err error)

TrySend sends value to the ch channel, blocked until context closed or value passed to the channel.

func TrySendError

func TrySendError[T any](ctx context.Context, ch chan<- Option[T], err error) (_ error)

TrySendError sends err to the ch channel, blocked until context closed or value passed to the channel.

func With

func With(ctx context.Context, opt ...OptFunc) (context.Context, context.CancelFunc)

With returns the new context containing optional values from opt funcs and context cancel func.

Types

type Func

type Func[T any] func(chan<- Option[T]) error

Func is a channel writer callback.

type OptFunc

type OptFunc func(ctx context.Context) context.Context

func Wait

func Wait() OptFunc

type Option

type Option[T any] struct {
	// contains filtered or unexported fields
}

Option is a wrapped pair of value and error.

func MakeErr

func MakeErr[T any](err error) Option[T]

MakeValue wraps error.

func MakeValue

func MakeValue[T any](v T) Option[T]

MakeValue wraps value.

func (Option[T]) Err

func (opt Option[T]) Err() error

Value unwraps opt's error.

func (Option[T]) Value

func (opt Option[T]) Value() T

Value unwraps opt's value.