Add note about len and [] operating on bytes

Fixes #148.

examples/string-functions/string-functions.go

@@ -14,10 +14,12 @@ var p = fmt.Println
 func main() {
 
     // Here's a sample of the functions available in
-    // `strings`. Note that these are all functions from the
+    // `strings`. Since these are functions from the
-    // package, not methods on the string object itself.
+    // package, not methods on the string object itself,
-    // This means that we need pass the string in question
+    // we need pass the string in question as the first
-    // as the first argument to the function.
+    // argument to the function. You can find more
+    // functions in the [`strings`](http://golang.org/pkg/strings/)
+    // package docs.
     p("Contains:  ", s.Contains("test", "es"))
     p("Count:     ", s.Count("test", "t"))
     p("HasPrefix: ", s.HasPrefix("test", "te"))
@@ -32,12 +34,16 @@ func main() {
     p("ToUpper:   ", s.ToUpper("test"))
     p()
 
-    // You can find more functions in the [`strings`](http://golang.org/pkg/strings/)
+    // Not part of `strings`, but worth mentioning here, are
-    // package docs.
+    // the mechanisms for getting the length of a string in
-
+    // bytes and getting a byte by index.
-    // Not part of `strings` but worth mentioning here are
-    // the mechanisms for getting the length of a string
-    // and getting a character by index.
     p("Len: ", len("hello"))
     p("Char:", "hello"[1])
 }
+
+// Note that `len` and indexing above work at the byte level.
+// Go uses UTF-8 encoded strings, so this is often useful
+// as-is. If you're working with potentially multi-byte
+// characters you'll want to use encoding-aware operations.
+// See [strings, bytes, runes and characters in Go](https://blog.golang.org/strings)
+// for more information.

examples/string-functions/string-functions.hash

@@ -1,2 +1,2 @@
-d7150ce50772abdaf827082093613134cb05e08f
+17aa523bbd606fa0b624fae44b89812d46330755
-Gkc5rDaeaN
+Lf5_Zbg6or

public/string-functions

@@ -41,7 +41,7 @@ to give you a sense of the package.</p>
             
           </td>
           <td class="code leading">
-	        <a href="http://play.golang.org/p/Gkc5rDaeaN"><img title="Run code" src="play.png" class="run" /></a>
+	        <a href="http://play.golang.org/p/Lf5_Zbg6or"><img title="Run code" src="play.png" class="run" /></a>
             <div class="highlight"><pre><span class="kn">package</span> <span class="nx">main</span>
 </pre></div>
 
@@ -90,10 +90,12 @@ it a lot below.</p>
         <tr>
           <td class="docs">
             <p>Here&rsquo;s a sample of the functions available in
-<code>strings</code>. Note that these are all functions from the
+<code>strings</code>. Since these are functions from the
-package, not methods on the string object itself.
+package, not methods on the string object itself,
-This means that we need pass the string in question
+we need pass the string in question as the first
-as the first argument to the function.</p>
+argument to the function. You can find more
+functions in the <a href="http://golang.org/pkg/strings/"><code>strings</code></a>
+package docs.</p>
 
           </td>
           <td class="code leading">
@@ -118,29 +120,33 @@ as the first argument to the function.</p>
         
         <tr>
           <td class="docs">
-            <p>You can find more functions in the <a href="http://golang.org/pkg/strings/"><code>strings</code></a>
+            <p>Not part of <code>strings</code>, but worth mentioning here, are
-package docs.</p>
+the mechanisms for getting the length of a string in
+bytes and getting a byte by index.</p>
 
           </td>
-          <td class="code empty leading">
+          <td class="code leading">
 	        
+            <div class="highlight"><pre>    <span class="nx">p</span><span class="p">(</span><span class="s">&quot;Len: &quot;</span><span class="p">,</span> <span class="nb">len</span><span class="p">(</span><span class="s">&quot;hello&quot;</span><span class="p">))</span>
+    <span class="nx">p</span><span class="p">(</span><span class="s">&quot;Char:&quot;</span><span class="p">,</span> <span class="s">&quot;hello&quot;</span><span class="p">[</span><span class="mi">1</span><span class="p">])</span>
+<span class="p">}</span>
+</pre></div>
 
           </td>
         </tr>
         
         <tr>
           <td class="docs">
-            <p>Not part of <code>strings</code> but worth mentioning here are
+            <p>Note that <code>len</code> and indexing above work at the byte level.
-the mechanisms for getting the length of a string
+Go uses UTF-8 encoded strings, so this is often useful
-and getting a character by index.</p>
+as-is. If you&rsquo;re working with potentially multi-byte
+characters you&rsquo;ll want to use encoding-aware operations.
+See <a href="https://blog.golang.org/strings">strings, bytes, runes and characters in Go</a>
+for more information.</p>
 
           </td>
-          <td class="code">
+          <td class="code empty">
 	        
-            <div class="highlight"><pre>    <span class="nx">p</span><span class="p">(</span><span class="s">&quot;Len: &quot;</span><span class="p">,</span> <span class="nb">len</span><span class="p">(</span><span class="s">&quot;hello&quot;</span><span class="p">))</span>
-    <span class="nx">p</span><span class="p">(</span><span class="s">&quot;Char:&quot;</span><span class="p">,</span> <span class="s">&quot;hello&quot;</span><span class="p">[</span><span class="mi">1</span><span class="p">])</span>
-<span class="p">}</span>
-</pre></div>
             
           </td>
         </tr>