From 79f00eeea3e2db027696de64741bc71fc8e67c39 Mon Sep 17 00:00:00 2001
From: steveklabnik <steve@steveklabnik.com>
Date: Mon, 6 Mar 2017 12:23:15 -0500
Subject: [PATCH 1/3] Implement playpen support for ```rust

Fixes #29
---
 src/renderer/html_handlebars/hbs_renderer.rs | 26 ++++++++++++++++----
 1 file changed, 21 insertions(+), 5 deletions(-)

diff --git a/src/renderer/html_handlebars/hbs_renderer.rs b/src/renderer/html_handlebars/hbs_renderer.rs
index 7c06fd62..124c8968 100644
--- a/src/renderer/html_handlebars/hbs_renderer.rs
+++ b/src/renderer/html_handlebars/hbs_renderer.rs
@@ -97,12 +97,11 @@ impl Renderer for HtmlHandlebars {
 
                         let filename = Path::new(&ch.path).with_extension("html");
 
-                        // create links for headers and fix anchors
+                        // Do several kinds of post-processing
                         let rendered = build_header_links(rendered, filename.to_str().unwrap_or(""));
                         let rendered = fix_anchor_links(rendered, filename.to_str().unwrap_or(""));
-
-                        // fix code blocks
                         let rendered = fix_code_blocks(rendered);
+                        let rendered = add_playpen_pre(rendered);
 
                         // Write to file
                         info!("[*] Creating {:?} ✓", filename.display());
@@ -146,11 +145,12 @@ impl Renderer for HtmlHandlebars {
         debug!("[*]: Render template");
 
         let rendered = try!(handlebars.render("index", &data));
+
+        // do several kinds of post-processing
         let rendered = build_header_links(rendered, "print.html");
         let rendered = fix_anchor_links(rendered, "print.html");
-
-        // fix code blocks
         let rendered = fix_code_blocks(rendered);
+        let rendered = add_playpen_pre(rendered);
 
         try!(book.write_file(Path::new("print").with_extension("html"), &rendered.into_bytes()));
         info!("[*] Creating print.html ✓");
@@ -292,3 +292,19 @@ fn fix_code_blocks(html: String) -> String {
         format!("<code{before}class=\"{classes}\"{after}>", before=before, classes=classes, after=after)
     }).into_owned()
 }
+
+fn add_playpen_pre(html: String) -> String {
+    let regex = Regex::new(r##"((?s)<code[^>]?class="([^"]+)".*?>.*?</code>)"##).unwrap();
+    regex.replace_all(&html, |caps: &Captures| {
+        let text = &caps[1];
+        let classes = &caps[2];
+
+        if classes.contains("language-rust") && !classes.contains("ignore") {
+            // wrap the contents in an external pre block
+            format!("<pre class=\"playpen\">{}</pre>", text)
+        } else {
+            // not language-rust, so no-op
+            format!("{}", text)
+        }
+    }).into_owned()
+}

From c5f9625feb102406324f18ec717b350cd8eaeee6 Mon Sep 17 00:00:00 2001
From: steveklabnik <steve@steveklabnik.com>
Date: Mon, 6 Mar 2017 13:27:25 -0500
Subject: [PATCH 2/3] inject main

---
 src/renderer/html_handlebars/hbs_renderer.rs | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/renderer/html_handlebars/hbs_renderer.rs b/src/renderer/html_handlebars/hbs_renderer.rs
index 124c8968..65ec2d43 100644
--- a/src/renderer/html_handlebars/hbs_renderer.rs
+++ b/src/renderer/html_handlebars/hbs_renderer.rs
@@ -294,14 +294,23 @@ fn fix_code_blocks(html: String) -> String {
 }
 
 fn add_playpen_pre(html: String) -> String {
-    let regex = Regex::new(r##"((?s)<code[^>]?class="([^"]+)".*?>.*?</code>)"##).unwrap();
+    let regex = Regex::new(r##"((?s)<code[^>]?class="([^"]+)".*?>(.*?)</code>)"##).unwrap();
     regex.replace_all(&html, |caps: &Captures| {
         let text = &caps[1];
         let classes = &caps[2];
+        let code = &caps[3];
 
         if classes.contains("language-rust") && !classes.contains("ignore") {
             // wrap the contents in an external pre block
-            format!("<pre class=\"playpen\">{}</pre>", text)
+
+            if text.contains("fn main") {
+                format!("<pre class=\"playpen\">{}</pre>", text)
+            } else {
+                // we need to inject our own main
+                format!("<pre class=\"playpen\"><code class=\"{}\">#fn main() {{
+{}
+#}}</code></pre>", classes, code)
+            }
         } else {
             // not language-rust, so no-op
             format!("{}", text)

From b120ce739785a115cd1627608d831ac796899d27 Mon Sep 17 00:00:00 2001
From: steveklabnik <steve@steveklabnik.com>
Date: Fri, 10 Mar 2017 09:46:11 -0500
Subject: [PATCH 3/3] inject allow(unused_variables)

---
 src/renderer/html_handlebars/hbs_renderer.rs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/renderer/html_handlebars/hbs_renderer.rs b/src/renderer/html_handlebars/hbs_renderer.rs
index 65ec2d43..a36fc83a 100644
--- a/src/renderer/html_handlebars/hbs_renderer.rs
+++ b/src/renderer/html_handlebars/hbs_renderer.rs
@@ -307,7 +307,9 @@ fn add_playpen_pre(html: String) -> String {
                 format!("<pre class=\"playpen\">{}</pre>", text)
             } else {
                 // we need to inject our own main
-                format!("<pre class=\"playpen\"><code class=\"{}\">#fn main() {{
+                format!("<pre class=\"playpen\"><code class=\"{}\"># #![allow(unused_variables)]
+# 
+#fn main() {{
 {}
 #}}</code></pre>", classes, code)
             }