Allow HTML comments inside lists

Fixes #21.

README.md

@@ -45,7 +45,7 @@ instead of
 
 Every Ecmarkdown string is a either a **numeric list**, a **paragraph**, or a **fragment**. These base productions can contain other productions.
 
-**Numeric lists** are written as a series of lines, each starting with `1. `. Lines can be indented by multiples of exactly two spaces to indicate nesting. To convert a numeric list, use `ecmarkdown.list(stringOfText)` to get back HTML for the list (with root element `<ol>`).
+**Numeric lists** are written as a series of lines, each starting with `1. `. Lines can be indented by multiples of exactly two spaces to indicate nesting. To convert a numeric list, use `ecmarkdown.list(stringOfText)` to get back HTML for the list (with root element `<ol>`). HTML is allowed inside list items, where it is passed through untouched, but HTML tags cannot span multiple list items. The exception is HTML comments (`<!-- -->`), which can span multiple lines.
 
 **Paragraphs** are a single line of text. To convert a paragraph, use `ecmarkdown.paragraph(stringOfText)` to get back HTML for the paragraph (with root element `<p>`).
 

lib/actions.js

@@ -24,11 +24,7 @@ exports.list = function (lines, state) {
     var ols = state.ols;
 
     lines.forEach(function (line) {
-        var dents = line[0];
-        var liNumber = line[1];
-        var li = line[3];
-
-        dents.forEach(function (dent) {
+        line.dents.forEach(function (dent) {
             if (dent === INDENT) {
                 var currentLI = ols.current.children(':last-of-type');
                 var newOL = $('<ol>');
@@ -40,16 +36,33 @@ exports.list = function (lines, state) {
         });
 
         // Set the start="" attribute from the list item number if this is the first <li> in the <ol>.
-        if (liNumber !== '1' && ols.current.children().length === 0) {
-            ols.current.attr('start', liNumber);
+        if (line.type === 'listLine' && line.number !== '1' && ols.current.children().length === 0) {
+            ols.current.attr('start', line.number);
         }
 
-        ols.current.append(li);
+        ols.current.append(line.node);
     });
 
     return beautify($.html(ols.emptyAndReturnBottom()));
 };
 
+exports.listLine = function (dents, number, li) {
+    return {
+        type: 'listLine',
+        dents: dents,
+        number: number,
+        node: li
+    };
+};
+
+exports.comment = function (dents, content) {
+    return {
+        type: 'comment',
+        dents: dents,
+        node: $('<!--' + content + '-->')
+    };
+};
+
 exports.listItem = function (atoms) {
     var li = $('<li>');
     atoms.forEach(function (atom) {

lib/grammar.pegjs

@@ -3,20 +3,27 @@
     var state = actions.makeInitialState();
 }
 
-// Entry points
+// ## Entry points
 
-list = lines:(dents $[0-9]+ ". " listItem "\n")+                           { return actions.list(lines, state); }
+list = lines:(listLine / comment)+                                         { return actions.list(lines, state); }
 
 paragraph = atoms:atom+                                                    { return actions.paragraph(atoms); }
 
 fragment = atoms:atom+                                                     { return actions.fragment(atoms); }
 
-// Supporting productions
+// ## Supporting productions
 
-dents = spaces:"  "*                                                       { return actions.dents(spaces, state); }
+dents = spaces:indentSpaces                                                { return actions.dents(spaces, state); }
+
+// The prelude here ensures we don't gobble up any dents unless we are definitely in a list line instead of a comment
+listLine = &(indentSpaces number)
+           dents:dents number:number ". " li:listItem "\n"                 { return actions.listLine(dents,
+                                                                                                     number, li); }
 
 listItem = atoms:atom+                                                     { return actions.listItem(atoms); }
 
+comment = dents:dents "<!--" content:$(!"-->" .)* "-->" "\n"?              { return actions.comment(dents, content); }
+
 atom = variable
      / code
      / string
@@ -41,3 +48,7 @@ nonterminal = "|" name:$[a-z]i+ params:("[" $[^\]]+ "]")? opt:"_opt"? "|"  { ret
                                                                                                         params, opt); }
 
 normalText = $[^\n]
+
+indentSpaces = "  "*
+
+number = $[0-9]+

test/list-cases/html-comment-inside-item.ecmarkdown

@@ -0,0 +1,3 @@
+1. Start
+2. Middle <!-- comment -->
+3. End

test/list-cases/html-comment-inside-item.html

@@ -0,0 +1,7 @@
+<ol>
+  <li>Start</li>
+  <li>Middle
+    <!-- comment -->
+  </li>
+  <li>End</li>
+</ol>

test/list-cases/html-comment-multiline-2.ecmarkdown

@@ -0,0 +1,5 @@
+1. Start
+<!-- 2. Comment out
+3. Two lines but with the end marker on the next line
+-->
+4. End

test/list-cases/html-comment-multiline-2.html

@@ -0,0 +1,7 @@
+<ol>
+  <li>Start</li>
+  <!-- 2. Comment out
+3. Two lines but with the end marker on the next line
+-->
+  <li>End</li>
+</ol>

test/list-cases/html-comment-multiline-3.ecmarkdown

@@ -0,0 +1,4 @@
+1. Start
+2. Comment <!-- out
+3. Two lines -->
+4. End

test/list-cases/html-comment-multiline-3.html

@@ -0,0 +1,6 @@
+<ol>
+  <li>Start</li>
+  <li>Comment
+    <!-- out</li><li>Two lines --></li>
+  <li>End</li>
+</ol>

test/list-cases/html-comment-multiline.ecmarkdown

@@ -0,0 +1,4 @@
+1. Start
+<!-- 2. Comment out
+3. Two lines -->
+4. End

test/list-cases/html-comment-multiline.html

@@ -0,0 +1,6 @@
+<ol>
+  <li>Start</li>
+  <!-- 2. Comment out
+3. Two lines -->
+  <li>End</li>
+</ol>

test/list-cases/html-comment-nested-list.ecmarkdown

@@ -0,0 +1,3 @@
+1. abc
+  <!-- comment -->
+  5. def

test/list-cases/html-comment-nested-list.html

@@ -0,0 +1,8 @@
+<ol>
+  <li>abc
+    <ol start="5">
+      <!-- comment -->
+      <li>def</li>
+    </ol>
+  </li>
+</ol>

test/list-cases/html-comment-singleline.ecmarkdown

@@ -0,0 +1,3 @@
+1. Start
+<!-- 2. Comment out one line -->
+3. End

test/list-cases/html-comment-singleline.html

@@ -0,0 +1,5 @@
+<ol>
+  <li>Start</li>
+  <!-- 2. Comment out one line -->
+  <li>End</li>
+</ol>