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@nickcarenza
Created February 20, 2015 18:35
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Golang Lazy Evaluation
package main
import (
"time"
)
type LazyInt chan func() int
// Can't use pointer receiver: invalid operation: l <- (func literal) (send to non-chan type *LazyInt)
func (l LazyInt) Future(i int) {
l <- func() int {
time.Sleep(3 * time.Second)
return i
}
}
func (l LazyInt) Add(i int) {
old := <-l
l <- func() int { return old() + i }
}
func addLazily(x LazyInt, y LazyInt) int {
return (<-x)() + (<-y)()
}
func main() {
var i = 1
var a = make(LazyInt, 1)
var b = make(LazyInt, 1)
a <- func() int { return i }
b <- func() int { return i }
sum := addLazily(a, b)
println(sum)
var c = make(LazyInt, 1)
c.Future(5)
c.Add(3)
println((<-c)())
}
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