There is no automatic fall through, but cases can be presented in comma-separated lists. +
func shouldEscape(c byte) bool {
switch c {
@@ -727,6 +728,7 @@ func shouldEscape(c byte) bool {
Here's a comparison routine for byte arrays that uses two
switch statements:
+
// Compare returns an integer comparing the two byte arrays,
// lexicographically.
@@ -1180,6 +1182,7 @@ structure with length 10 and a capacity of 100 pointing at the first
for more information.)
In contrast, new([]int) returns a pointer to a newly allocated, zeroed slice
structure, that is, a pointer to a nil slice value.
+
These examples illustrate the difference between new and
@@ -1330,6 +1333,8 @@ func Append(slice, data[]byte) []byte {
We must return the slice afterwards because, although Append
can modify the elements of slice, the slice itself (the run-time data
structure holding the pointer, length, and capacity) is passed by value.
+
+
The idea of appending to a slice is so useful it's captured by the
append built-in function. To understand that function's
@@ -1545,6 +1550,7 @@ a space in the format (% x) it puts spaces between the bytes.
Another handy format is %T, which prints the type of a value.
+
fmt.Printf("%T\n", timeZone)
@@ -1606,6 +1612,7 @@ func Println(v ...interface{}) {
We write ... after v in the nested call to Sprintln to tell the
compiler to treat v as a list of arguments; otherwise it would just pass
v as a single slice argument.
+
There's even more to printing than we've covered here. See the godoc documentation
for package fmt for the details.
@@ -1783,6 +1790,7 @@ func init() {
Methods can be defined for any named type that is not a pointer or an interface;
the receiver does not have to be a struct.
+
In the discussion of slices above, we wrote an Append
function. We can define it as a method on slices instead. To do
@@ -2012,6 +2020,7 @@ Those methods include the standard Write method, so an
can be used.
Request is a struct containing a parsed representation
of the request from the client.
+
For brevity, let's ignore POSTs and assume HTTP requests are always
GETs; that simplification does not affect the way the handlers are
@@ -2034,6 +2043,7 @@ func (ctr *Counter) ServeHTTP(w http.ResponseWriter, req *http.Request) {
(Keeping with our theme, note how Fprintf can print to an
http.ResponseWriter.)
For reference, here's how to attach such a server to a node on the URL tree.
+
import "net/http"
...
@@ -2187,6 +2197,7 @@ what a Reader does and what a Writer
does; it is a union of the embedded interfaces (which must be disjoint
sets of methods).
Only interfaces can be embedded within interfaces.
+
The same basic idea applies to structs, but with more far-reaching
implications. The bufio package has two struct types,
@@ -2378,10 +2389,11 @@ exits, silently. (The effect is similar to the Unix shell's
background.)
-go list.Sort() // run list.Sort concurrently; don't wait for it.
+go list.Sort() // run list.Sort concurrently; don't wait for it.
A function literal can be handy in a goroutine invocation.
+
func Announce(message string, delay time.Duration) {
go func() {
@@ -2393,6 +2405,7 @@ func Announce(message string, delay time.Duration) {
In Go, function literals are closures: the implementation makes
sure the variables referred to by the function survive as long as they are active.
+
These examples aren't too practical because the functions have no way of signaling
completion. For that, we need channels.
@@ -2425,7 +2438,7 @@ c := make(chan int) // Allocate a channel.
// Start the sort in a goroutine; when it completes, signal on the channel.
go func() {
list.Sort()
- c <- 1 // Send a signal; value does not matter.
+ c <- 1 // Send a signal; value does not matter.
}()
doSomethingForAWhile()
<-c // Wait for sort to finish; discard sent value.
@@ -2494,6 +2507,7 @@ One of the most important properties of Go is that
a channel is a first-class value that can be allocated and passed
around like any other. A common use of this property is
to implement safe, parallel demultiplexing.
+
In the example in the previous section, handle was
an idealized handler for a request but we didn't define the
@@ -3026,7 +3040,7 @@ TODO
verifying implementation
type Color uint32
-
+
// Check that Color implements image.Color and image.Image
var _ image.Color = Black
var _ image.Image = Black