examples: clean up examples and add blinky1 for Arduino

Arduino has trouble supporting anything that's not extremely simple, so
add a simple blinky example for it. Also, it may be useful anyway.

src/examples/test/test.go

@@ -0,0 +1,154 @@
+package main
+
+// This file is here to test features of the Go compiler.
+
+import "unicode"
+
+type Thing struct {
+	name string
+}
+
+func (t Thing) String() string {
+	return t.name
+}
+
+type Stringer interface {
+	String() string
+}
+
+const SIX = 6
+
+var testmap = map[string]int{"data": 3}
+
+func main() {
+	println("Hello world from Go!")
+	println("The answer is:", calculateAnswer())
+	println("5 ** 2 =", square(5))
+	println("3 + 12 =", add(3, 12))
+	println("fib(11) =", fib(11))
+	println("sumrange(100) =", sumrange(100))
+	println("strlen foo:", strlen("foo"))
+
+	// map
+	m := map[string]int{"answer": 42, "foo": 3}
+	readMap(m, "answer")
+	readMap(testmap, "data")
+
+	// slice
+	foo := []int{1, 2, 4, 5}
+	println("len/cap foo:", len(foo), cap(foo))
+	println("foo[3]:", foo[3])
+	println("sum foo:", sum(foo))
+
+	// interfaces, pointers
+	thing := &Thing{"foo"}
+	println("thing:", thing.String())
+	printItf(5)
+	printItf(byte('x'))
+	printItf("foo")
+	printItf(*thing)
+	printItf(thing)
+	printItf(Stringer(thing))
+	s := Stringer(thing)
+	println("Stringer.String():", s.String())
+
+	// unusual calls
+	runFunc(hello, 5) // must be indirect to avoid obvious inlining
+	testDefer()
+	testBound(thing.String)
+	func() {
+		println("thing inside closure:", thing.String()) //, len(foo))
+	}()
+	runFunc(func(i int) {
+		println("inside fp closure:", thing.String(), i)
+	}, 3)
+
+	// test library functions
+	println("lower to upper char:", 'h', "->", unicode.ToUpper('h'))
+}
+
+func runFunc(f func(int), arg int) {
+	f(arg)
+}
+
+func testDefer() {
+	i := 1
+	defer deferred("...run as defer", i)
+	i += 1
+	defer deferred("...run as defer", i)
+	println("deferring...")
+}
+
+func deferred(msg string, i int) {
+	println(msg, i)
+}
+
+func testBound(f func() string) {
+	println("bound method:", f())
+}
+
+func readMap(m map[string]int, key string) {
+	println("map length:", len(m))
+	println("map read:", key, "=", m[key])
+}
+
+func hello(n int) {
+	println("hello from function pointer:", n)
+}
+
+func strlen(s string) int {
+	return len(s)
+}
+
+func printItf(val interface{}) {
+	switch val := val.(type) {
+	case int:
+		println("is int:", val)
+	case byte:
+		println("is byte:", val)
+	case string:
+		println("is string:", val)
+	case Thing:
+		println("is Thing:", val.String())
+	case *Thing:
+		println("is *Thing:", val.String())
+	default:
+		println("is ?")
+	}
+}
+
+func calculateAnswer() int {
+	seven := 7
+	return SIX * seven
+}
+
+func square(n int) int {
+	return n * n
+}
+
+func add(a, b int) int {
+	return a + b
+}
+
+func fib(n int) int {
+	if n <= 2 {
+		return 1
+	}
+	return fib(n-1) + fib(n-2)
+}
+
+func sumrange(n int) int {
+	sum := 0
+	for i := 1; i <= n; i++ {
+		sum += i
+	}
+	return sum
+}
+
+func sum(l []int) int {
+	sum := 0
+	for _, n := range l {
+		sum += n
+	}
+	return sum
+}