A Lazy type for synchronization of lazily-evaluated data.
Lazy controls a 0-argument function which can be used to initialize a captured pointer. To work around the lack of generics, Lazy can "control" this accompanying pointer, like Mutex.
package main
import lazy "github.com/reem/go-lazy"
import "fmt"
import "sync"
type Data struct {
int x
}
func main() {
// It is only legal to access data after thunk.Force has been called.
data := &Data{0}
thunk := lazy.Defer(func() {
fmt.Println("Expensive computation run!")
data.x = 45
})
// "Expensive computation run!" will be printed once
// some time after this.
var wg sync.WaitGroup
wg.Add(2)
go func() {
defer wg.Done()
thunk.Force()
fmt.Println("data.x:", data.x)
}()
go func() {
defer wg.Done()
thunk.Force()
fmt.Println("data.x:", data.x)
}()
wg.Wait()
}Jonathan Reem is the primary author and maintainer of future.
MIT