Add an "old" attribute to the pnum class to indicate pnum changes

README.md

@@ -301,6 +301,23 @@ the set contains the potential results of that operand.
 
 ![](img/pnum.png)
 
+If paragraph numbers are being added or changed we can use the `old` attribute:
+
+```markdown
+
+[3]{.pnum old=""} We can indicate new paragraph numbers via an empty `old` attribute
+
+[4]{.pnum old="3"} And old paragraph numbers
+
+[4.1]{.pnum old="4"} And changing the nesting
+
+[5]{.pnum old="5.1"} And vice versa
+
+[6.1]{.pnum old="5.1"} And both
+```
+
+![](img/pnum-old.png)
+
 #### Code Changes
 
 ![](img/code-diff.png)

TEST.md

@@ -266,6 +266,17 @@ an expression `e` is defined as follows:
   - [2.2]{.pnum} If `e` is a subscripting operation (7.6.1.1) with an array operand,
 the set contains the potential results of that operand.
 
+[3]{.pnum old=""} We can indicate new paragraph numbers via an empty `old` attribute
+
+[4]{.pnum old="3"} And old paragraph numbers
+
+[4.1]{.pnum old="4"} And changing the nesting
+
+[5]{.pnum old="5.1"} And vice versa
+
+[6.1]{.pnum old="5.1"} And both
+
+
 ## Wording Changes
 
 Large changes are `::: add` for additions, `::: rm` for removals.

data/filters/wg21.py

@@ -321,15 +321,20 @@ def protect_code(elem, doc):
 
     def pnum():
         num = pf.stringify(elem)
-
+        old_attribute = None
+        if "old" in elem.attributes:
+            old = elem.attributes["old"]
+            if '.' in old:
+                old = f'({old})'
+            old_attribute = f' data-old="{old}"';
         if '.' in num:
             num = f'({num})'
 
         if doc.format == 'latex':
             return pf.RawInline(f'\\pnum{{{num}}}', 'latex')
         elif doc.format == 'html':
             return pf.Span(
-                pf.RawInline(f'<a class="marginalized">{num}</a>', 'html'),
+                pf.RawInline(f'<a class="marginalized"{old_attribute if old_attribute != None else '' }>{num}</a>', 'html'),
                 classes=['marginalizedparent'])
 
         return pf.Superscript(pf.Str(num))

data/templates/wg21.html

@@ -32,6 +32,19 @@
       code.diff {color: #$uccolor$}
       code.diff span.va {color: #$addcolor$}
       code.diff span.st {color: #$rmcolor$}
+
+      .marginalized[data-old]::before {
+        text-decoration-line: line-through;
+        color: #$rmcolor$;
+        content: attr(data-old);
+      }
+      .marginalized[data-old] {
+        color: #$addcolor$;
+      }
+      .add .marginalized {
+        color: #$addcolor$;
+      }
+
 $endif$
   </style>
 $for(css)$

generated/TEST.html

@@ -4,7 +4,7 @@
   <meta charset="utf-8" />
   <meta name="generator" content="mpark/wg21" />
   <meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=yes" />
-  <meta name="dcterms.date" content="2024-12-15" />
+  <meta name="dcterms.date" content="2024-12-22" />
   <title>Test document for mpark/wg21</title>
   <style>
       code{white-space: pre-wrap;}
@@ -81,6 +81,19 @@
       code.diff {color: #898887}
       code.diff span.va {color: #006e28}
       code.diff span.st {color: #bf0303}
+
+      .marginalized[data-old]::before {
+        text-decoration-line: line-through;
+        color: #bf0303;
+        content: attr(data-old);
+      }
+      .marginalized[data-old] {
+        color: #006e28;
+      }
+      .add .marginalized {
+        color: #006e28;
+      }
+
   </style>
   <style type="text/css">
 body {
@@ -430,7 +443,7 @@ <h3 class="subtitle" style="text-align:center">Visual inspection of
   </tr>
   <tr>
     <td>Date:</td>
-    <td>2024-12-15</td>
+    <td>2024-12-22</td>
   </tr>
   <tr>
     <td style="vertical-align:top">Project:</td>
@@ -761,6 +774,17 @@ <h2 data-number="5.1" id="paragraph-numbers"><span class="header-section-number"
 (7.6.1.1) with an array operand, the set contains the potential results
 of that operand.</p></li>
 </ul>
+<p><span class="marginalizedparent"><a class="marginalized" data-old>3</a></span>
+We can indicate new paragraph numbers via an empty
+<code class="sourceCode cpp">old</code> attribute</p>
+<p><span class="marginalizedparent"><a class="marginalized" data-old="3">4</a></span>
+And old paragraph numbers</p>
+<p><span class="marginalizedparent"><a class="marginalized" data-old="4">(4.1)</a></span>
+And changing the nesting</p>
+<p><span class="marginalizedparent"><a class="marginalized" data-old="(5.1)">5</a></span>
+And vice versa</p>
+<p><span class="marginalizedparent"><a class="marginalized" data-old="(5.1)">(6.1)</a></span>
+And both</p>
 <h2 data-number="5.2" id="wording-changes"><span class="header-section-number">5.2</span> Wording Changes<a href="#wording-changes" class="self-link"></a></h2>
 <p>Large changes are
 <code class="sourceCode cpp"><span class="op">:::</span> add</code> for