summaryrefslogtreecommitdiff
path: root/go/nth-prime/nth_prime.go
diff options
context:
space:
mode:
Diffstat (limited to 'go/nth-prime/nth_prime.go')
-rw-r--r--go/nth-prime/nth_prime.go42
1 files changed, 42 insertions, 0 deletions
diff --git a/go/nth-prime/nth_prime.go b/go/nth-prime/nth_prime.go
new file mode 100644
index 0000000..7e01d8e
--- /dev/null
+++ b/go/nth-prime/nth_prime.go
@@ -0,0 +1,42 @@
+package prime
+
+func gen() (chan int, chan bool) {
+ stop := make(chan bool)
+ ch := make(chan int)
+ go func() {
+ defer close(ch)
+ for i := 2; ; i++ {
+ select {
+ case ch <- i:
+ case <-stop:
+ return
+ }
+ }
+ }()
+ return ch, stop
+}
+
+func filter(in chan int, prime int) chan int {
+ ch := make(chan int)
+ go func() {
+ defer close(ch)
+ for i := range in {
+ if i%prime != 0 {
+ ch <- i
+ }
+ }
+ }()
+ return ch
+}
+
+func Nth(n int) (int, bool) {
+ if n < 1 {
+ return 0, false
+ }
+ ch, stop := gen()
+ defer func() { stop <- true }()
+ for i := 1; i < n; i++ {
+ ch = filter(ch, <-ch)
+ }
+ return <-ch, true
+}