effective go: extract and test a couple more examples.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/4937045

doc/effective_go.html

@@ -1622,11 +1622,12 @@ enumerator.  Since <code>iota</code> can be part of an expression and
 expressions can be implicitly repeated, it is easy to build intricate
 sets of values.
 </p>
-<pre>
+<pre><!--{{code "progs/eff_bytesize.go" `/^type ByteSize/` `/^\)/`}}
-type ByteSize float64
+-->type ByteSize float64
+
 const (
-    _ = iota  // ignore first value by assigning to blank identifier
+    _           = iota // ignore first value by assigning to blank identifier
-    KB ByteSize = 1&lt;&lt;(10*iota)
+    KB ByteSize = 1 &lt;&lt; (10 * iota)
     MB
     GB
     TB
@@ -1641,27 +1642,27 @@ The ability to attach a method such as <code>String</code> to a
 type makes it possible for such values to format themselves
 automatically for printing, even as part of a general type.
 </p>
-<pre>
+<pre><!--{{code "progs/eff_bytesize.go" `/^func.*ByteSize.*String/` `/^}/`}}
-func (b ByteSize) String() string {
+-->func (b ByteSize) String() string {
     switch {
     case b &gt;= YB:
-        return fmt.Sprintf("%.2fYB", float64(b/YB))
+        return fmt.Sprintf(&#34;%.2fYB&#34;, float64(b/YB))
     case b &gt;= ZB:
-        return fmt.Sprintf("%.2fZB", float64(b/ZB))
+        return fmt.Sprintf(&#34;%.2fZB&#34;, float64(b/ZB))
     case b &gt;= EB:
-        return fmt.Sprintf("%.2fEB", float64(b/EB))
+        return fmt.Sprintf(&#34;%.2fEB&#34;, float64(b/EB))
     case b &gt;= PB:
-        return fmt.Sprintf("%.2fPB", float64(b/PB))
+        return fmt.Sprintf(&#34;%.2fPB&#34;, float64(b/PB))
     case b &gt;= TB:
-        return fmt.Sprintf("%.2fTB", float64(b/TB))
+        return fmt.Sprintf(&#34;%.2fTB&#34;, float64(b/TB))
     case b &gt;= GB:
-        return fmt.Sprintf("%.2fGB", float64(b/GB))
+        return fmt.Sprintf(&#34;%.2fGB&#34;, float64(b/GB))
     case b &gt;= MB:
-        return fmt.Sprintf("%.2fMB", float64(b/MB))
+        return fmt.Sprintf(&#34;%.2fMB&#34;, float64(b/MB))
     case b &gt;= KB:
-        return fmt.Sprintf("%.2fKB", float64(b/KB))
+        return fmt.Sprintf(&#34;%.2fKB&#34;, float64(b/KB))
     }
-    return fmt.Sprintf("%.2fB", float64(b))
+    return fmt.Sprintf(&#34;%.2fB&#34;, float64(b))
 }
 </pre>
 <p>
@@ -1812,8 +1813,8 @@ by the routines in package <code>sort</code> if it implements
 and it could also have a custom formatter.
 In this contrived example <code>Sequence</code> satisfies both.
 </p>
-<pre>
+<pre><!--{{code "progs/eff_sequence.go" `/^type/` "$"}}
-type Sequence []int
+-->type Sequence []int
 
 // Methods required by sort.Interface.
 func (s Sequence) Len() int {
@@ -1829,14 +1830,14 @@ func (s Sequence) Swap(i, j int) {
 // Method for printing - sorts the elements before printing.
 func (s Sequence) String() string {
     sort.Sort(s)
-    str := "["
+    str := &#34;[&#34;
     for i, elem := range s {
         if i &gt; 0 {
-            str += " "
+            str += &#34; &#34;
         }
         str += fmt.Sprint(elem)
     }
-    return str + "]"
+    return str + &#34;]&#34;
 }
 </pre>
 

doc/effective_go.tmpl

@@ -1622,48 +1622,13 @@ enumerator.  Since <code>iota</code> can be part of an expression and
 expressions can be implicitly repeated, it is easy to build intricate
 sets of values.
 </p>
-<pre>
+{{code "progs/eff_bytesize.go" `/^type ByteSize/` `/^\)/`}}
-type ByteSize float64
-const (
-    _ = iota  // ignore first value by assigning to blank identifier
-    KB ByteSize = 1&lt;&lt;(10*iota)
-    MB
-    GB
-    TB
-    PB
-    EB
-    ZB
-    YB
-)
-</pre>
 <p>
 The ability to attach a method such as <code>String</code> to a
 type makes it possible for such values to format themselves
 automatically for printing, even as part of a general type.
 </p>
-<pre>
+{{code "progs/eff_bytesize.go" `/^func.*ByteSize.*String/` `/^}/`}}
-func (b ByteSize) String() string {
-    switch {
-    case b &gt;= YB:
-        return fmt.Sprintf("%.2fYB", float64(b/YB))
-    case b &gt;= ZB:
-        return fmt.Sprintf("%.2fZB", float64(b/ZB))
-    case b &gt;= EB:
-        return fmt.Sprintf("%.2fEB", float64(b/EB))
-    case b &gt;= PB:
-        return fmt.Sprintf("%.2fPB", float64(b/PB))
-    case b &gt;= TB:
-        return fmt.Sprintf("%.2fTB", float64(b/TB))
-    case b &gt;= GB:
-        return fmt.Sprintf("%.2fGB", float64(b/GB))
-    case b &gt;= MB:
-        return fmt.Sprintf("%.2fMB", float64(b/MB))
-    case b &gt;= KB:
-        return fmt.Sprintf("%.2fKB", float64(b/KB))
-    }
-    return fmt.Sprintf("%.2fB", float64(b))
-}
-</pre>
 <p>
 (The <code>float64</code> conversions prevent <code>Sprintf</code> 
 from recurring back through the <code>String</code> method for 
@@ -1812,33 +1777,7 @@ by the routines in package <code>sort</code> if it implements
 and it could also have a custom formatter.
 In this contrived example <code>Sequence</code> satisfies both.
 </p>
-<pre>
+{{code "progs/eff_sequence.go" `/^type/` "$"}}
-type Sequence []int
-
-// Methods required by sort.Interface.
-func (s Sequence) Len() int {
-    return len(s)
-}
-func (s Sequence) Less(i, j int) bool {
-    return s[i] &lt; s[j]
-}
-func (s Sequence) Swap(i, j int) {
-    s[i], s[j] = s[j], s[i]
-}
-
-// Method for printing - sorts the elements before printing.
-func (s Sequence) String() string {
-    sort.Sort(s)
-    str := "["
-    for i, elem := range s {
-        if i &gt; 0 {
-            str += " "
-        }
-        str += fmt.Sprint(elem)
-    }
-    return str + "]"
-}
-</pre>
 
 <h3 id="conversions">Conversions</h3>
 

doc/progs/eff_bytesize.go

@@ -0,0 +1,47 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import "fmt"
+
+type ByteSize float64
+
+const (
+	_           = iota // ignore first value by assigning to blank identifier
+	KB ByteSize = 1 << (10 * iota)
+	MB
+	GB
+	TB
+	PB
+	EB
+	ZB
+	YB
+)
+
+func (b ByteSize) String() string {
+	switch {
+	case b >= YB:
+		return fmt.Sprintf("%.2fYB", float64(b/YB))
+	case b >= ZB:
+		return fmt.Sprintf("%.2fZB", float64(b/ZB))
+	case b >= EB:
+		return fmt.Sprintf("%.2fEB", float64(b/EB))
+	case b >= PB:
+		return fmt.Sprintf("%.2fPB", float64(b/PB))
+	case b >= TB:
+		return fmt.Sprintf("%.2fTB", float64(b/TB))
+	case b >= GB:
+		return fmt.Sprintf("%.2fGB", float64(b/GB))
+	case b >= MB:
+		return fmt.Sprintf("%.2fMB", float64(b/MB))
+	case b >= KB:
+		return fmt.Sprintf("%.2fKB", float64(b/KB))
+	}
+	return fmt.Sprintf("%.2fB", float64(b))
+}
+
+func main() {
+	fmt.Println(YB, ByteSize(1e13))
+}

doc/progs/eff_sequence.go

@@ -0,0 +1,42 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"fmt"
+	"sort"
+)
+
+func main() {
+	seq := Sequence{6, 2, -1, 44, 16}
+	sort.Sort(seq)
+	fmt.Println(seq)
+}
+
+type Sequence []int
+
+// Methods required by sort.Interface.
+func (s Sequence) Len() int {
+	return len(s)
+}
+func (s Sequence) Less(i, j int) bool {
+	return s[i] < s[j]
+}
+func (s Sequence) Swap(i, j int) {
+	s[i], s[j] = s[j], s[i]
+}
+
+// Method for printing - sorts the elements before printing.
+func (s Sequence) String() string {
+	sort.Sort(s)
+	str := "["
+	for i, elem := range s {
+		if i > 0 {
+			str += " "
+		}
+		str += fmt.Sprint(elem)
+	}
+	return str + "]"
+}

doc/progs/run

@@ -35,7 +35,9 @@ for i in \
 	sieve1.go \
 	server1.go \
 	strings.go \
+	eff_bytesize.go\
 	eff_qr.go \
+	eff_sequence.go\
 ; do
 	$GC $i
 done
@@ -83,4 +85,7 @@ testitpipe sieve "sed 10q" "2 3 5 7 11 13 17 19 23 29"
 $GC server.go
 testit server1 "" ""
 
+testit eff_bytesize "" "1.00YB 9.09TB"
+testit eff_sequence "" "[-1 2 6 16 44]"
+
 rm -f $O.out *.$O