deploy: b055f44

book.js

@@ -108,9 +108,12 @@ function playground_text(playground) {
 
         let text = playground_text(code_block);
         let classes = code_block.querySelector('code').classList;
-        let has_2018 = classes.contains("edition2018");
-        let edition = has_2018 ? "2018" : "2015";
-
+        let edition = "2015";
+        if(classes.contains("edition2018")) {
+            edition = "2018";
+        } else if(classes.contains("edition2021")) {
+            edition = "2021";
+        }
         var params = {
             version: "stable",
             optimize: "0",
@@ -133,7 +136,15 @@ function playground_text(playground) {
             body: JSON.stringify(params)
         })
         .then(response => response.json())
-        .then(response => result_block.innerText = response.result)
+        .then(response => {
+            if (response.result.trim() === '') {
+                result_block.innerText = "No output";
+                result_block.classList.add("result-no-output");
+            } else {
+                result_block.innerText = response.result;
+                result_block.classList.remove("result-no-output");
+            }
+        })
         .catch(error => result_block.innerText = "Playground Communication: " + error.message);
     }
 
@@ -151,12 +162,13 @@ function playground_text(playground) {
     if (window.ace) {
         // language-rust class needs to be removed for editable
         // blocks or highlightjs will capture events
-        Array
-            .from(document.querySelectorAll('code.editable'))
+        code_nodes
+            .filter(function (node) {return node.classList.contains("editable"); })
             .forEach(function (block) { block.classList.remove('language-rust'); });
 
         Array
-            .from(document.querySelectorAll('code:not(.editable)'))
+        code_nodes
+            .filter(function (node) {return !node.classList.contains("editable"); })
             .forEach(function (block) { hljs.highlightBlock(block); });
     } else {
         code_nodes.forEach(function (block) { hljs.highlightBlock(block); });

css/general.css

@@ -175,3 +175,7 @@ blockquote {
     margin: 5px 0px;
     font-weight: bold;
 }
+
+.result-no-output {
+    font-style: italic;
+}

lang/index.html

@@ -156,7 +156,7 @@ <h2 id="programming-languages"><a class="header" href="#programming-languages">P
 <h3 id="general"><a class="header" href="#general">General</a></h3>
 <p>The code samples from Kernighan's talks tend to use <a href="./C.html">C</a> and <a href="./awk.html">AWK</a>.</p>
 <ul>
-<li>1974: <a href="https://archive.org/details/elementsofprogra00kernrich/mode/2up">The Elements of Programming Style</a>
+<li>1974: <a href="https://archive.org/details/elementsofprogra00kernrich/mode/2up">The Elements of Programming Style</a> (<a href="http://www2.ing.unipi.it/%7Ea009435/issw/extra/kp_elems_of_pgmng_sty.pdf">PDF</a>) (<a href="https://seriouscomputerist.atariverse.com/media/pdf/book/Elements%20of%20Programming%20Style.pdf">2e PDF</a>)
 <ul>
 <li>by Brian W. Kernighan and <a href="https://www.plauger.com/">Phillip James Plaugher</a></li>
 <li>title refers to William Strunk's <a href="https://www.gutenberg.org/ebooks/37134">The Elements of Style</a> (1918)</li>

lang/regex.html

@@ -165,16 +165,20 @@ <h3 id="regular-expressions"><a class="header" href="#regular-expressions">Regul
 <li>by Rob Pike</li>
 </ul>
 </li>
-<li>2003: <a href="https://www.regular-expressions.info/quickstart.html">Regular-Expressions.info</a>
+<li>2007: <a href="https://swtch.com/%7Ersc/regexp/">Implementing Regular Expressions</a> (<a href="https://swtch.com/%7Ersc/talks/regexp.pdf">lecture</a>)
 <ul>
-<li>by <a href="https://www.just-great-software.com/aboutjg.html">Jan Goyvaerts</a></li>
+<li>by <a href="https://swtch.com/%7Ersc/">Russ Cox</a></li>
 </ul>
 </li>
-<li>2007: <a href="https://swtch.com/%7Ersc/regexp/">Implementing Regular Expressions</a> (<a href="https://swtch.com/%7Ersc/talks/regexp.pdf">lecture</a>)
+</ul>
+<h4 id="other-resources"><a class="header" href="#other-resources">Other resources</a></h4>
 <ul>
-<li>by <a href="https://swtch.com/%7Ersc/">Russ Cox</a></li>
+<li>2003: <a href="https://www.regular-expressions.info/quickstart.html">Regular-Expressions.info</a>
+<ul>
+<li>by <a href="https://www.just-great-software.com/aboutjg.html">Jan Goyvaerts</a></li>
 </ul>
 </li>
+<li><a href="https://en.wikipedia.org/wiki/Wikipedia:AutoWikiBrowser/Regular_expression">Regular expression tables on Wikipedia</a></li>
 </ul>
 
                     </main>

print.html

@@ -628,7 +628,7 @@ <h1 id="awards"><a class="header" href="#awards">Awards</a></h1>
 <h3 id="general"><a class="header" href="#general">General</a></h3>
 <p>The code samples from Kernighan's talks tend to use <a href="lang/./C.html">C</a> and <a href="lang/./awk.html">AWK</a>.</p>
 <ul>
-<li>1974: <a href="https://archive.org/details/elementsofprogra00kernrich/mode/2up">The Elements of Programming Style</a>
+<li>1974: <a href="https://archive.org/details/elementsofprogra00kernrich/mode/2up">The Elements of Programming Style</a> (<a href="http://www2.ing.unipi.it/%7Ea009435/issw/extra/kp_elems_of_pgmng_sty.pdf">PDF</a>) (<a href="https://seriouscomputerist.atariverse.com/media/pdf/book/Elements%20of%20Programming%20Style.pdf">2e PDF</a>)
 <ul>
 <li>by Brian W. Kernighan and <a href="https://www.plauger.com/">Phillip James Plaugher</a></li>
 <li>title refers to William Strunk's <a href="https://www.gutenberg.org/ebooks/37134">The Elements of Style</a> (1918)</li>
@@ -952,16 +952,20 @@ <h2 id="b"><a class="header" href="#b">B</a></h2>
 <li>by Rob Pike</li>
 </ul>
 </li>
-<li>2003: <a href="https://www.regular-expressions.info/quickstart.html">Regular-Expressions.info</a>
+<li>2007: <a href="https://swtch.com/%7Ersc/regexp/">Implementing Regular Expressions</a> (<a href="https://swtch.com/%7Ersc/talks/regexp.pdf">lecture</a>)
 <ul>
-<li>by <a href="https://www.just-great-software.com/aboutjg.html">Jan Goyvaerts</a></li>
+<li>by <a href="https://swtch.com/%7Ersc/">Russ Cox</a></li>
 </ul>
 </li>
-<li>2007: <a href="https://swtch.com/%7Ersc/regexp/">Implementing Regular Expressions</a> (<a href="https://swtch.com/%7Ersc/talks/regexp.pdf">lecture</a>)
+</ul>
+<h4 id="other-resources"><a class="header" href="#other-resources">Other resources</a></h4>
 <ul>
-<li>by <a href="https://swtch.com/%7Ersc/">Russ Cox</a></li>
+<li>2003: <a href="https://www.regular-expressions.info/quickstart.html">Regular-Expressions.info</a>
+<ul>
+<li>by <a href="https://www.just-great-software.com/aboutjg.html">Jan Goyvaerts</a></li>
 </ul>
 </li>
+<li><a href="https://en.wikipedia.org/wiki/Wikipedia:AutoWikiBrowser/Regular_expression">Regular expression tables on Wikipedia</a></li>
 </ul>
 <div style="break-before: page; page-break-before: always;"></div><h3 id="go"><a class="header" href="#go">Go</a></h3>
 <p>Go is a new programming language designed by many people, some of whom are the UNIX author(s). It is sponsored and developed at Google.</p>