From b15e848a2d47e2123ea89ccf94ffb7430b7ecd53 Mon Sep 17 00:00:00 2001 From: Oling Cat Date: Sat, 22 Sep 2012 05:55:16 +1000 Subject: [release-branch.go1] doc/effective_go: Closed some tags; removed extra spaces. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit ««« backport 04608c28273f doc/effective_go: Closed some tags; removed extra spaces. R=golang-dev, adg CC=golang-dev https://golang.org/cl/6488122 »»» --- doc/effective_go.html | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) mode change 100644 => 100755 doc/effective_go.html diff --git a/doc/effective_go.html b/doc/effective_go.html old mode 100644 new mode 100755 index d38b781b45..012ed9053d --- a/doc/effective_go.html +++ b/doc/effective_go.html @@ -714,6 +714,7 @@ func unhex(c byte) byte {

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
-- 
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