tutorial: remove all line numbers and references to them.

R=golang-dev, mikioh.mikioh, dsymonds
CC=golang-dev
https://golang.org/cl/4675070

doc/go_tutorial.html

@@ -19,9 +19,6 @@ The presentation here proceeds through a series of modest programs to illustrate
 key features of the language.  All the programs work (at time of writing) and are
 checked into the repository in the directory <a href='/doc/progs'><code>/doc/progs/</code></a>.
 <p>
-Program snippets are annotated with the line number in the original file; for
-cleanliness, blank lines remain blank.
-<p>
 <h2>Hello, World</h2>
 <p>
 Let's start in the usual way:
@@ -176,12 +173,13 @@ a naming conflict.
 <p>
 Given <code>os.Stdout</code> we can use its <code>WriteString</code> method to print the string.
 <p>
-Having imported the <code>flag</code> package, line 12 creates a global variable to hold
+After importing the <code>flag</code> package, we use a <code>var</code> declaration
-the value of echo's <code>-n</code> flag. The variable <code>omitNewline</code> has type <code>*bool</code>, pointer
+to create and initialize a global variable, called <code>omitNewline</code>,
-to <code>bool</code>.
+to hold the value of echo's <code>-n</code> flag. 
+The variable  has type <code>*bool</code>, pointer to <code>bool</code>.
 <p>
-In <code>main.main</code>, we parse the arguments (line 20) and then create a local
+In <code>main.main</code>, we parse the arguments (the call to <code>flag.Parse</code>) and then create a local
-string variable we will use to build the output.
+string variable with which to build the output.
 <p>
 The declaration statement has the form
 <p>
@@ -261,7 +259,9 @@ reassigning it.  This snippet from <code>strings.go</code> is legal code:
 <p>
 <pre><!-- progs/strings.go /hello/ /ciao/
 -->    s := &#34;hello&#34;
-    if s[1] != 'e' { os.Exit(1) }
+    if s[1] != 'e' {
+        os.Exit(1)
+    }
     s = &#34;good bye&#34;
     var p *string = &amp;s
     *p = &#34;ciao&#34;
@@ -540,7 +540,7 @@ return n
 </pre>
 <p>
 but for simple structures like <code>File</code> it's easier to return the address of a 
-composite literal, as is done here on line 21.
+composite literal, as is done here in the <code>return</code> statement from <code>newFile</code>.
 <p>
 We can use the factory to construct some familiar, exported variables of type <code>*File</code>:
 <p>
@@ -573,9 +573,9 @@ multi-value return as a parenthesized list of declarations; syntactically
 they look just like a second parameter list.  The function
 <code>syscall.Open</code>
 also has a multi-value return, which we can grab with the multi-variable
-declaration on line 31; it declares <code>r</code> and <code>e</code> to hold the two values,
+declaration on the first line; it declares <code>r</code> and <code>e</code> to hold the two values,
 both of type <code>int</code> (although you'd have to look at the <code>syscall</code> package
-to see that).  Finally, line 35 returns two values: a pointer to the new <code>File</code>
+to see that).  Finally, <code>OpenFile</code> returns two values: a pointer to the new <code>File</code>
 and the error.  If <code>syscall.Open</code> fails, the file descriptor <code>r</code> will
 be negative and <code>newFile</code> will return <code>nil</code>.
 <p>
@@ -1013,7 +1013,7 @@ can just say <code>%d</code>; <code>Printf</code> knows the size and signedness
 integer and can do the right thing for you.  The snippet
 <p>
 <pre><!-- progs/print.go 10 11
--->    var u64 uint64 = 1&lt;&lt;64-1
+-->    var u64 uint64 = 1&lt;&lt;64 - 1
     fmt.Printf(&#34;%d %d\n&#34;, u64, int64(u64))
 </pre>
 <p>
@@ -1204,7 +1204,7 @@ operator <code>&lt;-</code> (receive) retrieves the next value on the channel.
 func filter(in, out chan int, prime int) {
     for {
         i := &lt;-in // Receive value of new variable &#39;i&#39; from &#39;in&#39;.
-        if i % prime != 0 {
+        if i%prime != 0 {
             out &lt;- i // Send &#39;i&#39; to channel &#39;out&#39;.
         }
     }
@@ -1262,7 +1262,7 @@ of <code>generate</code>, from <code>progs/sieve1.go</code>:
 <pre><!-- progs/sieve1.go /func.generate/ /^}/
 -->func generate() chan int {
     ch := make(chan int)
-    go func(){
+    go func() {
         for i := 2; ; i++ {
             ch &lt;- i
         }
@@ -1288,7 +1288,7 @@ The same change can be made to <code>filter</code>:
     out := make(chan int)
     go func() {
         for {
-            if i := &lt;-in; i % prime != 0 {
+            if i := &lt;-in; i%prime != 0 {
                 out &lt;- i
             }
         }
@@ -1396,8 +1396,8 @@ does it check the results.
         req.replyc = make(chan int)
         adder &lt;- req
     }
-    for i := N-1; i &gt;= 0; i-- {   // doesn&#39;t matter what order
+    for i := N - 1; i &gt;= 0; i-- { // doesn&#39;t matter what order
-        if &lt;-reqs[i].replyc != N + 2*i {
+        if &lt;-reqs[i].replyc != N+2*i {
             fmt.Println(&#34;fail at&#34;, i)
         }
     }

doc/go_tutorial.txt

@@ -20,9 +20,6 @@ The presentation here proceeds through a series of modest programs to illustrate
 key features of the language.  All the programs work (at time of writing) and are
 checked into the repository in the directory <a href='/doc/progs'>"/doc/progs/"</a>.
 
-Program snippets are annotated with the line number in the original file; for
-cleanliness, blank lines remain blank.
-
 Hello, World
 ----
 
@@ -136,12 +133,13 @@ a naming conflict.
 
 Given "os.Stdout" we can use its "WriteString" method to print the string.
 
-Having imported the "flag" package, line 12 creates a global variable to hold
+After importing the "flag" package, we use a "var" declaration
-the value of echo's "-n" flag. The variable "omitNewline" has type "*bool", pointer
+to create and initialize a global variable, called "omitNewline",
-to "bool".
+to hold the value of echo's "-n" flag. 
+The variable  has type "*bool", pointer to "bool".
 
-In "main.main", we parse the arguments (line 20) and then create a local
+In "main.main", we parse the arguments (the call to "flag.Parse") and then create a local
-string variable we will use to build the output.
+string variable with which to build the output.
 
 The declaration statement has the form
 
@@ -429,7 +427,7 @@ object.  We could write
 	return n
 
 but for simple structures like "File" it's easier to return the address of a 
-composite literal, as is done here on line 21.
+composite literal, as is done here in the "return" statement from "newFile".
 
 We can use the factory to construct some familiar, exported variables of type "*File":
 
@@ -447,9 +445,9 @@ multi-value return as a parenthesized list of declarations; syntactically
 they look just like a second parameter list.  The function
 "syscall.Open"
 also has a multi-value return, which we can grab with the multi-variable
-declaration on line 31; it declares "r" and "e" to hold the two values,
+declaration on the first line; it declares "r" and "e" to hold the two values,
 both of type "int" (although you'd have to look at the "syscall" package
-to see that).  Finally, line 35 returns two values: a pointer to the new "File"
+to see that).  Finally, "OpenFile" returns two values: a pointer to the new "File"
 and the error.  If "syscall.Open" fails, the file descriptor "r" will
 be negative and "newFile" will return "nil".