goobird's Introduction

GooBird

Write elegant asynchronous code using promises.

Features

Easily create promises

p := promise.Create(func() (interface{}, interface{}) {
  time.Sleep(100 * time.Milliseconds)
  return 42, nil
})

fmt.Println("Waiting...")

x,_ := p.Wait()

fmt.Println("x =", x)

prints

Waiting...
x = 42

Use of Then to chain promises

x,err := promise.Create(func() (interface{}, interface{}) {
  return 42, nil
}).Then(func(res interface{}) (interface{}, interface{}) {
  x := res.(int)
  return x * 2, nil
}).Wait()

Nest promises (works in Then too)

x,err := promise.Create(func() (interface{}, interface{}) {
  return promise.Create(func() (interface{}, interface{}) { return 42, nil }, nil
}).Then(func(res interface{}) (interface{}, interface{}) {
  x := res.(int)
  return x * 2
}).Wait()

Run arrays/slices of promises

x,err := promise.Create(func() (interface{}, interface{}) {
  return [...]*SPromise{
    Create(func() (interface{}, interface{}) { return 1, nil }),
    Create(func() (interface{}, interface{}) { return 2, nil }),
    Create(func() (interface{}, interface{}) { return 3, nil }),
  }, nil
}).All().Wait()

Fast

Uses a single GoRoutine per promise to run serial links in the chain and uses metuxes instead of channels to synchronize the promises.

Todo

Features

Each: Run a function on all items of an array and return an array
Map: Run a function on each item of a map and return a map, order not guarenteed
Reduce: Run a function to reduce an array to a single value, order not guarenteed
Filter: Run a function to filter an array to contain only specific values