all: implement parser and HTML renderer for table of contents

The current implementation only support toc position "auto" (default)
and "preamble" with option to set toc level and title.

3 files changed, 134 insertions, 2 deletions

diff --git a/testdata/got.test.html b/testdata/got.test.html
index e991647..47cb37f 100644
--- a/testdata/got.test.html
+++ b/testdata/got.test.html
@@ -46,6 +46,71 @@
 </div>
 </div>
 </div>
+<div id="toc" class="toc">
+<div id="toctitle">Table of Contents</div>
+<ul class="sectlevel1">
+<li><a href="#_inline_formatting_on_section"><em>Inline <code>formatting</code> on <strong>section</strong></em></a></li>
+<li><a href="#_comment">Comment</a></li>
+<li><a href="#_paragraph">Paragraph</a></li>
+<li><a href="#_unconstrained_text_formatting">Unconstrained text formatting</a></li>
+<li><a href="#_single_quote">Single quote</a></li>
+<li><a href="#_subscript_and_superscript">Subscript and superscript</a></li>
+<li><a href="#_constrained_text_formatting">Constrained text formatting</a></li>
+<li><a href="#_blocks">Blocks</a>
+<ul class="sectlevel2">
+<li><a href="#_title">Title</a></li>
+</ul>
+</li>
+<li><a href="#_literal_block">Literal block</a></li>
+<li><a href="#_ordered_lists">Ordered Lists</a></li>
+<li><a href="#_unordered_lists">Unordered Lists</a></li>
+<li><a href="#_mixed_list">Mixed list</a></li>
+<li><a href="#_description_list">Description list</a>
+<ul class="sectlevel2">
+<li><a href="#_with_horizontal">With [horizontal]</a></li>
+<li><a href="#_with_title">With title</a></li>
+<li><a href="#_indented_with_space">Indented with space</a></li>
+<li><a href="#_with">With "+"</a></li>
+<li><a href="#_mixed_with_list">Mixed with list</a></li>
+<li><a href="#_spread">Spread</a></li>
+<li><a href="#_mixed_with_ordered_and_unordered_list">Mixed with ordered and unordered list</a></li>
+</ul>
+</li>
+<li><a href="#_question_and_answers">Question and Answers</a></li>
+<li><a href="#_horizontal_rules">Horizontal rules</a></li>
+<li><a href="#_page_break">Page break</a></li>
+<li><a href="#_urls">URLs</a></li>
+<li><a href="#_block_images">Block images</a>
+<ul class="sectlevel2">
+<li><a href="#_float_group">Float group</a></li>
+<li><a href="#_inline_image">Inline image</a></li>
+</ul>
+</li>
+<li><a href="#_block_open">Block open</a></li>
+<li><a href="#_video">Video</a></li>
+<li><a href="#_audio">Audio</a></li>
+<li><a href="#_admonition">Admonition</a>
+<ul class="sectlevel2">
+<li><a href="#_line_admonition">Line admonition</a></li>
+<li><a href="#_style_admonition">Style admonition</a></li>
+<li><a href="#_icons">Icons</a></li>
+</ul>
+</li>
+<li><a href="#_sidebar">Sidebar</a></li>
+<li><a href="#_example">Example</a></li>
+<li><a href="#_quote">Quote</a>
+<ul class="sectlevel2">
+<li><a href="#_quoted_paragraph">Quoted paragraph</a></li>
+</ul>
+</li>
+<li><a href="#_verse">Verse</a></li>
+<li><a href="#_passthrough">Passthrough</a>
+<ul class="sectlevel2">
+<li><a href="#_block_passthrough">Block passthrough</a></li>
+</ul>
+</li>
+</ul>
+</div>
 </div>
 <div class="sect1">
 <h2 id="_inline_formatting_on_section"><em>Inline <code>formatting</code> on <strong>section</strong></em></h2>
@@ -1717,7 +1782,7 @@ and then moves on.</pre>
 <div id="footer">
 <div id="footer-text">
 Version 1.1.1<br>
-Last updated 2020-10-29 16:49:47 +0700
+Last updated 2020-10-29 22:28:22 +0700
 </div>
 </div>
 </body>
diff --git a/testdata/test.adoc b/testdata/test.adoc
index 8805c34..9b79149 100644
--- a/testdata/test.adoc
+++ b/testdata/test.adoc
@@ -3,6 +3,8 @@
 Author A, Author B
 :unclosed metadata:
 v1.1.1, 18 July 2020
+:toc: preamble
+:toclevels: 4
 
 This is preamble.
 :other metadata:
diff --git a/testdata/test.html b/testdata/test.html
index 89b9bc7..cf13574 100644
--- a/testdata/test.html
+++ b/testdata/test.html
@@ -46,6 +46,71 @@
 </div>
 </div>
 </div>
+<div id="toc" class="toc">
+<div id="toctitle">Table of Contents</div>
+<ul class="sectlevel1">
+<li><a href="#_inline_formatting_on_section"><em>Inline <code>formatting</code> on <strong>section</strong></em></a></li>
+<li><a href="#_comment">Comment</a></li>
+<li><a href="#_paragraph">Paragraph</a></li>
+<li><a href="#_unconstrained_text_formatting">Unconstrained text formatting</a></li>
+<li><a href="#_single_quote">Single quote</a></li>
+<li><a href="#_subscript_and_superscript">Subscript and superscript</a></li>
+<li><a href="#_constrained_text_formatting">Constrained text formatting</a></li>
+<li><a href="#_blocks">Blocks</a>
+<ul class="sectlevel2">
+<li><a href="#_title">Title</a></li>
+</ul>
+</li>
+<li><a href="#_literal_block">Literal block</a></li>
+<li><a href="#_ordered_lists">Ordered Lists</a></li>
+<li><a href="#_unordered_lists">Unordered Lists</a></li>
+<li><a href="#_mixed_list">Mixed list</a></li>
+<li><a href="#_description_list">Description list</a>
+<ul class="sectlevel2">
+<li><a href="#_with_horizontal">With [horizontal]</a></li>
+<li><a href="#_with_title">With title</a></li>
+<li><a href="#_indented_with_space">Indented with space</a></li>
+<li><a href="#_with">With "+"</a></li>
+<li><a href="#_mixed_with_list">Mixed with list</a></li>
+<li><a href="#_spread">Spread</a></li>
+<li><a href="#_mixed_with_ordered_and_unordered_list">Mixed with ordered and unordered list</a></li>
+</ul>
+</li>
+<li><a href="#_question_and_answers">Question and Answers</a></li>
+<li><a href="#_horizontal_rules">Horizontal rules</a></li>
+<li><a href="#_page_break">Page break</a></li>
+<li><a href="#_urls">URLs</a></li>
+<li><a href="#_block_images">Block images</a>
+<ul class="sectlevel2">
+<li><a href="#_float_group">Float group</a></li>
+<li><a href="#_inline_image">Inline image</a></li>
+</ul>
+</li>
+<li><a href="#_block_open">Block open</a></li>
+<li><a href="#_video">Video</a></li>
+<li><a href="#_audio">Audio</a></li>
+<li><a href="#_admonition">Admonition</a>
+<ul class="sectlevel2">
+<li><a href="#_line_admonition">Line admonition</a></li>
+<li><a href="#_style_admonition">Style admonition</a></li>
+<li><a href="#_icons">Icons</a></li>
+</ul>
+</li>
+<li><a href="#_sidebar">Sidebar</a></li>
+<li><a href="#_example">Example</a></li>
+<li><a href="#_quote">Quote</a>
+<ul class="sectlevel2">
+<li><a href="#_quoted_paragraph">Quoted paragraph</a></li>
+</ul>
+</li>
+<li><a href="#_verse">Verse</a></li>
+<li><a href="#_passthrough">Passthrough</a>
+<ul class="sectlevel2">
+<li><a href="#_block_passthrough">Block passthrough</a></li>
+</ul>
+</li>
+</ul>
+</div>
 </div>
 <div class="sect1">
 <h2 id="_inline_formatting_on_section"><em>Inline <code>formatting</code> on <strong>section</strong></em></h2>
@@ -1713,7 +1778,7 @@ and then moves on.</pre>
 <div id="footer">
 <div id="footer-text">
 Version 1.1.1<br>
-Last updated 2020-10-29 16:49:47 +0700
+Last updated 2020-10-29 22:28:21 +0700
 </div>
 </div>
 </body>