first

course/13-channels/exercises/6-range/code.go

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+package main
+
+import (
+	"fmt"
+	"time"
+)
+
+func concurrrentFib(n int) {
+	// ?
+}
+
+// TEST SUITE - Don't touch below this line
+
+func test(n int) {
+	fmt.Printf("Printing %v numbers...\n", n)
+	concurrrentFib(n)
+	fmt.Println("==============================")
+}
+
+func main() {
+	test(10)
+	test(5)
+	test(20)
+	test(13)
+}
+
+func fibonacci(n int, ch chan int) {
+	x, y := 0, 1
+	for i := 0; i < n; i++ {
+		ch <- x
+		x, y = y, x+y
+		time.Sleep(time.Millisecond * 10)
+	}
+	close(ch)
+}

course/13-channels/exercises/6-range/complete.go

@@ -0,0 +1,40 @@
+package main
+
+import (
+	"fmt"
+	"time"
+)
+
+func concurrrentFib(n int) {
+	ch := make(chan int)
+	go fibonacci(n, ch)
+
+	for v := range ch {
+		fmt.Println(v)
+	}
+}
+
+// TEST SUITE - Don't touch below this line
+
+func test(n int) {
+	fmt.Printf("Printing %v numbers...\n", n)
+	concurrrentFib(n)
+	fmt.Println("==============================")
+}
+
+func main() {
+	test(10)
+	test(5)
+	test(20)
+	test(13)
+}
+
+func fibonacci(n int, ch chan int) {
+	x, y := 0, 1
+	for i := 0; i < n; i++ {
+		ch <- x
+		x, y = y, x+y
+		time.Sleep(time.Millisecond * 10)
+	}
+	close(ch)
+}

course/13-channels/exercises/6-range/expected.txt

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+Printing 10 numbers...
+0
+1
+1
+2
+3
+5
+8
+13
+21
+34
+==============================
+Printing 5 numbers...
+0
+1
+1
+2
+3
+==============================
+Printing 20 numbers...
+0
+1
+1
+2
+3
+5
+8
+13
+21
+34
+55
+89
+144
+233
+377
+610
+987
+1597
+2584
+4181
+==============================
+Printing 13 numbers...
+0
+1
+1
+2
+3
+5
+8
+13
+21
+34
+55
+89
+144
+==============================

course/13-channels/exercises/6-range/readme.md

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+# Range
+
+Similar to slices and maps, channels can be ranged over.
+
+```go
+for item := range ch {
+    // item is the next value received from the channel
+}
+```
+
+This example will receive values over the channel (blocking at each iteration if nothing new is there) and will exit only when the channel is closed.
+
+## Assignment
+
+It's that time again, Mailio is hiring and we've been assigned to do the interview. For some reason, the [Fibonacci sequence](https://en.wikipedia.org/wiki/Fibonacci_number) is Mailio's interview problem of choice. We've been tasked with building a small toy program we can use in the interview.
+
+Complete the `concurrrentFib` function. It should:
+
+* Create a new channel of `int`s
+* Call `fibonacci` in a goroutine, passing it the channel and the number of Fibonacci numbers to generate, `n`
+* Use a `range` loop to read from the channel and print out the numbers one by one, each on a new line