From faae7485b791150895cb51eedd1c5996ace760c1 Mon Sep 17 00:00:00 2001
From: Alex Kocharin <alex@kocharin.ru>
Date: Sat, 15 Nov 2014 04:20:00 +0300
Subject: [PATCH] Add footnote rules

---
 lib/parser_block.js                    |   1 +
 lib/parser_core.js                     |  17 +--
 lib/parser_inline.js                   |  30 +++--
 lib/renderer.js                        |  23 ++++
 lib/rules_block/footnote.js            |  67 +++++++++
 lib/rules_core/footnote_block.js       |  88 ++++++++++++
 lib/rules_inline/footnote_inline.js    |  54 ++++++++
 lib/rules_inline/footnote_ref.js       |  52 +++++++
 test/fixtures/remarkable/footnotes.txt | 179 +++++++++++++++++++++++++
 9 files changed, 489 insertions(+), 22 deletions(-)
 create mode 100644 lib/rules_block/footnote.js
 create mode 100644 lib/rules_core/footnote_block.js
 create mode 100644 lib/rules_inline/footnote_inline.js
 create mode 100644 lib/rules_inline/footnote_ref.js
 create mode 100644 test/fixtures/remarkable/footnotes.txt

diff --git a/lib/parser_block.js b/lib/parser_block.js
index 87001f6..3da8c49 100644
--- a/lib/parser_block.js
+++ b/lib/parser_block.js
@@ -14,6 +14,7 @@ var _rules = [
   [ 'blockquote', require('./rules_block/blockquote'), [ 'paragraph', 'blockquote', 'list' ] ],
   [ 'hr',         require('./rules_block/hr'),         [ 'paragraph', 'blockquote', 'list' ] ],
   [ 'list',       require('./rules_block/list'),       [ 'paragraph', 'blockquote' ] ],
+  [ 'footnote',   require('./rules_block/footnote'),   [ 'paragraph' ] ],
   [ 'heading',    require('./rules_block/heading'),    [ 'paragraph', 'blockquote' ] ],
   [ 'lheading',   require('./rules_block/lheading') ],
   [ 'htmlblock',  require('./rules_block/htmlblock'),  [ 'paragraph', 'blockquote' ] ],
diff --git a/lib/parser_core.js b/lib/parser_core.js
index 512c926..fc44f3d 100644
--- a/lib/parser_core.js
+++ b/lib/parser_core.js
@@ -7,14 +7,15 @@ var Ruler  = require('./ruler');
 
 
 var _rules = [
-  [ 'block',        require('./rules_core/block')        ],
-  [ 'abbr',         require('./rules_core/abbr')         ],
-  [ 'references',   require('./rules_core/references')   ],
-  [ 'inline',       require('./rules_core/inline')       ],
-  [ 'abbr2',        require('./rules_core/abbr2')        ],
-  [ 'replacements', require('./rules_core/replacements') ],
-  [ 'smartquotes',  require('./rules_core/smartquotes')  ],
-  [ 'linkify',      require('./rules_core/linkify')      ]
+  [ 'block',          require('./rules_core/block')          ],
+  [ 'abbr',           require('./rules_core/abbr')           ],
+  [ 'references',     require('./rules_core/references')     ],
+  [ 'inline',         require('./rules_core/inline')         ],
+  [ 'footnote_block', require('./rules_core/footnote_block') ],
+  [ 'abbr2',          require('./rules_core/abbr2')          ],
+  [ 'replacements',   require('./rules_core/replacements')   ],
+  [ 'smartquotes',    require('./rules_core/smartquotes')    ],
+  [ 'linkify',        require('./rules_core/linkify')        ]
 ];
 
 
diff --git a/lib/parser_inline.js b/lib/parser_inline.js
index 755eafd..e80faa1 100644
--- a/lib/parser_inline.js
+++ b/lib/parser_inline.js
@@ -11,20 +11,22 @@ var replaceEntities = require('./common/utils').replaceEntities;
 // Parser rules
 
 var _rules = [
-  [ 'text',       require('./rules_inline/text') ],
-  [ 'newline',    require('./rules_inline/newline') ],
-  [ 'escape',     require('./rules_inline/escape') ],
-  [ 'backticks',  require('./rules_inline/backticks') ],
-  [ 'del',        require('./rules_inline/del') ],
-  [ 'ins',        require('./rules_inline/ins') ],
-  [ 'mark',       require('./rules_inline/mark') ],
-  [ 'emphasis',   require('./rules_inline/emphasis') ],
-  [ 'sub',        require('./rules_inline/sub') ],
-  [ 'sup',        require('./rules_inline/sup') ],
-  [ 'links',      require('./rules_inline/links') ],
-  [ 'autolink',   require('./rules_inline/autolink') ],
-  [ 'htmltag',    require('./rules_inline/htmltag') ],
-  [ 'entity',     require('./rules_inline/entity') ]
+  [ 'text',            require('./rules_inline/text') ],
+  [ 'newline',         require('./rules_inline/newline') ],
+  [ 'escape',          require('./rules_inline/escape') ],
+  [ 'backticks',       require('./rules_inline/backticks') ],
+  [ 'del',             require('./rules_inline/del') ],
+  [ 'ins',             require('./rules_inline/ins') ],
+  [ 'mark',            require('./rules_inline/mark') ],
+  [ 'emphasis',        require('./rules_inline/emphasis') ],
+  [ 'sub',             require('./rules_inline/sub') ],
+  [ 'sup',             require('./rules_inline/sup') ],
+  [ 'links',           require('./rules_inline/links') ],
+  [ 'footnote_inline', require('./rules_inline/footnote_inline') ],
+  [ 'footnote_ref',    require('./rules_inline/footnote_ref') ],
+  [ 'autolink',        require('./rules_inline/autolink') ],
+  [ 'htmltag',         require('./rules_inline/htmltag') ],
+  [ 'entity',          require('./rules_inline/entity') ]
 ];
 
 
diff --git a/lib/renderer.js b/lib/renderer.js
index 4c1ff9a..05c693a 100644
--- a/lib/renderer.js
+++ b/lib/renderer.js
@@ -282,6 +282,29 @@ rules.abbr_close = function (/* tokens, idx, options, env */) {
 };
 
 
+rules.footnote_ref = function (tokens, idx) {
+  var id = Number(tokens[idx].id + 1).toString();
+  return '<a href="#fn' + id + '" class="footnoteRef" id="fnref' + id + '"><sup>' + id + '</sup></a>';
+};
+rules.footnote_block_open = function (tokens, idx, options) {
+  return '<div class="footnotes">\n' + (options.xhtmlOut ? '<hr />' : '<hr>') + '\n<ol>\n';
+};
+rules.footnote_block_close = function () {
+  return '</ol>\n</div>\n';
+};
+rules.footnote_open = function (tokens, idx) {
+  var id = Number(tokens[idx].id + 1).toString();
+  return '<li id="fn' + id + '">';
+};
+rules.footnote_close = function () {
+  return '</li>\n';
+};
+rules.footnote_anchor = function (tokens, idx) {
+  var id = Number(tokens[idx].id + 1).toString();
+  return '<a href="#fnref' + id + '">↩</a>';
+};
+
+
 // Renderer class
 function Renderer() {
   // Clone rules object to allow local modifications
diff --git a/lib/rules_block/footnote.js b/lib/rules_block/footnote.js
new file mode 100644
index 0000000..5d8362f
--- /dev/null
+++ b/lib/rules_block/footnote.js
@@ -0,0 +1,67 @@
+// Process footnote reference list
+
+'use strict';
+
+
+module.exports = function footnote(state, startLine, endLine, silent) {
+  var oldBMark, oldTShift, oldParentType, pos, label,
+      start = state.bMarks[startLine] + state.tShift[startLine],
+      max = state.eMarks[startLine];
+
+  // line should be at least 5 chars - "[^x]:"
+  if (start + 4 > max) { return false; }
+
+  if (state.src.charCodeAt(start) !== 0x5B/* [ */) { return false; }
+  if (state.src.charCodeAt(start + 1) !== 0x5E/* ^ */) { return false; }
+  if (state.level >= state.options.maxNesting) { return false; }
+
+  for (pos = start + 2; pos < max; pos++) {
+    if (state.src.charCodeAt(pos) === 0x20) { return false; }
+    if (state.src.charCodeAt(pos) === 0x5D /* ] */) {
+      break;
+    }
+  }
+
+  if (pos === start + 2) { return false; } // no empty footnote labels
+  if (pos + 1 >= max || state.src.charCodeAt(++pos) !== 0x3A /* : */) { return false; }
+  if (silent) { return true; }
+  pos++;
+
+  if (!state.env.footnotes) { state.env.footnotes = {}; }
+  if (!state.env.footnotes.available) { state.env.footnotes.available = Object.create(null); }
+  label = state.src.slice(start + 2, pos - 2);
+  state.env.footnotes.available[label] = true;
+
+  state.tokens.push({
+    type: 'footnote_reference_open',
+    label: label,
+    level: state.level++
+  });
+
+  oldBMark = state.bMarks[startLine];
+  oldTShift = state.tShift[startLine];
+  oldParentType = state.parentType;
+  state.tShift[startLine] = state.skipSpaces(pos) - pos;
+  state.bMarks[startLine] = pos;
+  state.blkIndent += 4;
+  state.parentType = 'footnote';
+
+  if (state.tShift[startLine] < state.blkIndent) {
+    state.tShift[startLine] += state.blkIndent;
+    state.bMarks[startLine] -= state.blkIndent;
+  }
+
+  state.parser.tokenize(state, startLine, endLine, true);
+
+  state.parentType = oldParentType;
+  state.blkIndent -= 4;
+  state.tShift[startLine] = oldTShift;
+  state.bMarks[startLine] = oldBMark;
+
+  state.tokens.push({
+    type: 'footnote_reference_close',
+    level: --state.level
+  });
+
+  return true;
+};
diff --git a/lib/rules_core/footnote_block.js b/lib/rules_core/footnote_block.js
new file mode 100644
index 0000000..4249474
--- /dev/null
+++ b/lib/rules_core/footnote_block.js
@@ -0,0 +1,88 @@
+'use strict';
+
+
+module.exports = function footnote_block(state) {
+  var i, l, t, list, tokens, current, currentLabel, anchor,
+      level = 0,
+      insideRef = false,
+      refTokens = Object.create(null);
+
+  if (!state.env.footnotes) { return; }
+
+  state.tokens = state.tokens.filter(function(tok) {
+    if (tok.type === 'footnote_reference_open') {
+      insideRef = true;
+      current = [];
+      currentLabel = tok.label;
+      return false;
+    }
+    if (tok.type === 'footnote_reference_close') {
+      insideRef = false;
+      refTokens[currentLabel] = current;
+      return false;
+    }
+    if (insideRef) { current.push(tok); }
+    return !insideRef;
+  });
+
+  if (!state.env.footnotes.list) { return; }
+  list = state.env.footnotes.list;
+
+  state.tokens.push({
+    type: 'footnote_block_open',
+    level: level++
+  });
+  for (i = 0, l = list.length; i < l; i++) {
+    state.tokens.push({
+      type: 'footnote_open',
+      id: i,
+      level: level++
+    });
+
+    if (list[i].tokens) {
+      tokens = [];
+      tokens.push({
+        type: 'paragraph_open',
+        tight: false,
+        level: level++
+      });
+      tokens.push({
+        type: 'inline',
+        content: '',
+        level: level,
+        children: list[i].tokens
+      });
+      tokens.push({
+        type: 'paragraph_close',
+        tight: false,
+        level: --level
+      });
+    } else if (list[i].label) {
+      tokens = refTokens[list[i].label];
+    }
+
+    anchor = {
+      type: 'footnote_anchor',
+      id: i,
+      level: level
+    };
+
+    state.tokens = state.tokens.concat(tokens);
+    if (state.tokens[state.tokens.length - 1].type === 'paragraph_close') {
+      t = state.tokens.pop();
+      state.tokens.push(anchor);
+      state.tokens.push(t);
+    } else {
+      state.tokens.push(anchor);
+    }
+
+    state.tokens.push({
+      type: 'footnote_close',
+      level: --level
+    });
+  }
+  state.tokens.push({
+    type: 'footnote_block_close',
+    level: --level
+  });
+};
diff --git a/lib/rules_inline/footnote_inline.js b/lib/rules_inline/footnote_inline.js
new file mode 100644
index 0000000..e5dc90a
--- /dev/null
+++ b/lib/rules_inline/footnote_inline.js
@@ -0,0 +1,54 @@
+// Process inline footnotes (^[...])
+
+'use strict';
+
+var parseLinkLabel = require('../helpers/parse_link_label');
+
+
+module.exports = function footnote_inline(state, silent) {
+  var labelStart,
+      labelEnd,
+      pos,
+      footnoteId,
+      oldLength,
+      max = state.posMax,
+      start = state.pos;
+
+  if (start + 2 >= max) { return false; }
+  if (state.src.charCodeAt(start) !== 0x5E/* ^ */) { return false; }
+  if (state.src.charCodeAt(start + 1) !== 0x5B/* [ */) { return false; }
+  if (state.level >= state.options.maxNesting) { return false; }
+
+  labelStart = start + 2;
+  labelEnd = parseLinkLabel(state, start + 1);
+
+  // parser failed to find ']', so it's not a valid note
+  if (labelEnd < 0) { return false; }
+
+  // We found the end of the link, and know for a fact it's a valid link;
+  // so all that's left to do is to call tokenizer.
+  //
+  if (!silent) {
+    if (!state.env.footnotes) { state.env.footnotes = {}; }
+    if (!state.env.footnotes.list) { state.env.footnotes.list = []; }
+    footnoteId = state.env.footnotes.list.length;
+
+    state.pos = labelStart;
+    state.posMax = labelEnd;
+
+    state.push({
+      type: 'footnote_ref',
+      id: footnoteId,
+      level: state.level
+    });
+    state.linkLevel++;
+    oldLength = state.tokens.length;
+    state.parser.tokenize(state);
+    state.env.footnotes.list[footnoteId] = { tokens: state.tokens.splice(oldLength) };
+    state.linkLevel--;
+  }
+
+  state.pos = pos;
+  state.posMax = max;
+  return true;
+};
diff --git a/lib/rules_inline/footnote_ref.js b/lib/rules_inline/footnote_ref.js
new file mode 100644
index 0000000..6fce842
--- /dev/null
+++ b/lib/rules_inline/footnote_ref.js
@@ -0,0 +1,52 @@
+// Process footnote references ([^...])
+
+'use strict';
+
+
+module.exports = function footnote_ref(state, silent) {
+  var label,
+      pos,
+      footnoteId,
+      max = state.posMax,
+      start = state.pos;
+
+  // should be at least 4 chars - "[^x]"
+  if (start + 3 > max) { return false; }
+
+  if (!state.env.footnotes || !state.env.footnotes.available) { return false; }
+  if (state.src.charCodeAt(start) !== 0x5B/* [ */) { return false; }
+  if (state.src.charCodeAt(start + 1) !== 0x5E/* ^ */) { return false; }
+  if (state.level >= state.options.maxNesting) { return false; }
+
+  for (pos = start + 2; pos < max; pos++) {
+    if (state.src.charCodeAt(pos) === 0x20) { return false; }
+    if (state.src.charCodeAt(pos) === 0x0A) { return false; }
+    if (state.src.charCodeAt(pos) === 0x5D /* ] */) {
+      break;
+    }
+  }
+
+  if (pos === start + 2) { return false; } // no empty footnote labels
+  if (pos >= max) { return false; }
+  pos++;
+
+  label = state.src.slice(start + 2, pos - 1);
+  if (!state.env.footnotes.available[label]) { return false; }
+
+  if (!silent) {
+    if (!state.env.footnotes.list) { state.env.footnotes.list = []; }
+    footnoteId = state.env.footnotes.list.length;
+
+    state.push({
+      type: 'footnote_ref',
+      id: footnoteId,
+      level: state.level
+    });
+
+    state.env.footnotes.list[footnoteId] = { label: label };
+  }
+
+  state.pos = pos;
+  state.posMax = max;
+  return true;
+};
diff --git a/test/fixtures/remarkable/footnotes.txt b/test/fixtures/remarkable/footnotes.txt
new file mode 100644
index 0000000..0a6ebaa
--- /dev/null
+++ b/test/fixtures/remarkable/footnotes.txt
@@ -0,0 +1,179 @@
+
+Pandoc example:
+.
+Here is a footnote reference,[^1] and another.[^longnote]
+
+[^1]: Here is the footnote.
+
+[^longnote]: Here's one with multiple blocks.
+
+    Subsequent paragraphs are indented to show that they
+belong to the previous footnote.
+
+        { some.code }
+
+    The whole paragraph can be indented, or just the first
+    line.  In this way, multi-paragraph footnotes work like
+    multi-paragraph list items.
+
+This paragraph won't be part of the note, because it
+isn't indented.
+.
+<p>Here is a footnote reference,<a href="#fn1" class="footnoteRef" id="fnref1"><sup>1</sup></a> and another.<a href="#fn2" class="footnoteRef" id="fnref2"><sup>2</sup></a></p>
+<p>This paragraph won’t be part of the note, because it
+isn’t indented.</p>
+<div class="footnotes">
+<hr>
+<ol>
+<li id="fn1"><p>Here is the footnote.<a href="#fnref1">↩</a></p>
+</li>
+<li id="fn2"><p>Here’s one with multiple blocks.</p>
+<p>Subsequent paragraphs are indented to show that they
+belong to the previous footnote.</p>
+<pre><code>{ some.code }
+</code></pre>
+<p>The whole paragraph can be indented, or just the first
+line.  In this way, multi-paragraph footnotes work like
+multi-paragraph list items.<a href="#fnref2">↩</a></p>
+</li>
+</ol>
+</div>
+.
+
+They could terminate each other:
+
+.
+[^1][^2][^3]
+
+[^1]: foo
+[^2]: bar
+[^3]: baz
+.
+<p><a href="#fn1" class="footnoteRef" id="fnref1"><sup>1</sup></a><a href="#fn2" class="footnoteRef" id="fnref2"><sup>2</sup></a><a href="#fn3" class="footnoteRef" id="fnref3"><sup>3</sup></a></p>
+<div class="footnotes">
+<hr>
+<ol>
+<li id="fn1"><p>foo<a href="#fnref1">↩</a></p>
+</li>
+<li id="fn2"><p>bar<a href="#fnref2">↩</a></p>
+</li>
+<li id="fn3"><p>baz<a href="#fnref3">↩</a></p>
+</li>
+</ol>
+</div>
+.
+
+
+They could be inside blockquotes, and are lazy:
+.
+[^foo]
+
+> [^foo]: bar
+baz
+.
+<p><a href="#fn1" class="footnoteRef" id="fnref1"><sup>1</sup></a></p>
+<blockquote>
+</blockquote>
+<div class="footnotes">
+<hr>
+<ol>
+<li id="fn1"><p>bar
+baz<a href="#fnref1">↩</a></p>
+</li>
+</ol>
+</div>
+.
+
+
+Their labels could not contain spaces or newlines:
+
+.
+[^ foo]: bar baz
+
+[^foo
+]: bar baz
+.
+<p>[^ foo]: bar baz</p>
+<p>[^foo
+]: bar baz</p>
+.
+
+We support inline notes too (pandoc example):
+
+.
+Here is an inline note.^[Inlines notes are easier to write, since
+you don't have to pick an identifier and move down to type the
+note.]
+.
+<p>Here is an inline note.<a href="#fn1" class="footnoteRef" id="fnref1"><sup>1</sup></a></p>
+<div class="footnotes">
+<hr>
+<ol>
+<li id="fn1"><p>Inlines notes are easier to write, since
+you don’t have to pick an identifier and move down to type the
+note.<a href="#fnref1">↩</a></p>
+</li>
+</ol>
+</div>
+.
+
+They could have arbitrary markup:
+
+.
+foo^[ *bar* ]
+.
+<p>foo<a href="#fn1" class="footnoteRef" id="fnref1"><sup>1</sup></a></p>
+<div class="footnotes">
+<hr>
+<ol>
+<li id="fn1"><p> <em>bar</em> <a href="#fnref1">↩</a></p>
+</li>
+</ol>
+</div>
+.
+
+Indents:
+
+.
+[^xxxxx] [^yyyyy]
+
+[^xxxxx]: foo
+    ---
+
+[^yyyyy]: foo
+   ---
+.
+<p><a href="#fn1" class="footnoteRef" id="fnref1"><sup>1</sup></a> <a href="#fn2" class="footnoteRef" id="fnref2"><sup>2</sup></a></p>
+<hr>
+<div class="footnotes">
+<hr>
+<ol>
+<li id="fn1"><h2>foo</h2>
+<a href="#fnref1">↩</a></li>
+<li id="fn2"><p>foo<a href="#fnref2">↩</a></p>
+</li>
+</ol>
+</div>
+.
+
+Indents for the first line:
+
+.
+[^xxxxx] [^yyyyy]
+
+[^xxxxx]:       foo
+
+[^yyyyy]:        foo
+.
+<p><a href="#fn1" class="footnoteRef" id="fnref1"><sup>1</sup></a> <a href="#fn2" class="footnoteRef" id="fnref2"><sup>2</sup></a></p>
+<div class="footnotes">
+<hr>
+<ol>
+<li id="fn1"><p>foo<a href="#fnref1">↩</a></p>
+</li>
+<li id="fn2"><pre><code>foo
+</code></pre>
+<a href="#fnref2">↩</a></li>
+</ol>
+</div>
+.