From 5f2eeed71d92d501e471591d873094489aa8811a Mon Sep 17 00:00:00 2001
From: Thibaut Lienart <tlienart@me.com>
Date: Sat, 1 Jan 2022 22:43:18 +0100
Subject: [PATCH] Nonumber (#940)

* adding nonumber and nonumber envs

* fixing the docs

* patch release
---
 Project.toml                   |  2 +-
 demos/index.md                 |  4 +--
 docs/_css/jtd.css              |  5 +++
 docs/faq/technical.md          | 56 +++++++++++++++++-----------------
 src/converter/latex/io.jl      | 12 +++++++-
 src/converter/latex/objects.jl | 15 ++++++---
 6 files changed, 58 insertions(+), 36 deletions(-)

diff --git a/Project.toml b/Project.toml
index 0ab5cd6ee..5566463bb 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "Franklin"
 uuid = "713c75ef-9fc9-4b05-94a9-213340da978e"
 authors = ["Thibaut Lienart <tlienart@me.com>"]
-version = "0.10.65"
+version = "0.10.66"
 
 [deps]
 Dates = "ade2ca70-3891-5945-98fb-dc099432e06a"
diff --git a/demos/index.md b/demos/index.md
index 0bf2012dc..e9a984be1 100644
--- a/demos/index.md
+++ b/demos/index.md
@@ -70,7 +70,7 @@ How to make a section expand when clicked, so that content is initially hidden?
 <script>
   var coll = document.getElementsByClassName("collapsible");
   var i;
-  
+
   for (i = 0; i < coll.length; i++) {
     coll[i].addEventListener("click", function() {
       this.classList.toggle("active");
@@ -88,7 +88,7 @@ How to make a section expand when clicked, so that content is initially hidden?
 
 With these definitions, the expandible code sections could be added!
 
-\collaps{An additional example: **Press here to expand**}{In the content part you can have latex: $x^2$, 
+\collaps{An additional example: **Press here to expand**}{In the content part you can have latex: $x^2$,
 
 lists
 * Item 1
diff --git a/docs/_css/jtd.css b/docs/_css/jtd.css
index d8d174d7a..7256baa8e 100644
--- a/docs/_css/jtd.css
+++ b/docs/_css/jtd.css
@@ -538,6 +538,11 @@ body { counter-reset: eqnum; }
     float: right;
     padding-right: 5px; }
 
+.nonumber .katex-display::after {
+  counter-increment: nothing;
+  content: "";
+}
+
 /* ==================================================================
     CODE & HIGHLIGHT.JS
 ================================================================== */
diff --git a/docs/faq/technical.md b/docs/faq/technical.md
index 5f83d34f9..9174d6db3 100644
--- a/docs/faq/technical.md
+++ b/docs/faq/technical.md
@@ -56,41 +56,41 @@ so you can style the back-reference via the `.franklin-content fndef td.fndef-ba
 
 ### How to disable numbering of math in display mode?
 
-It is possible to specify in the CSS which Katex equations will be numbered or not by adjusting the
-`.katex-display::after` class.
-If you want to disable numbering in the entire site, just head to `_css/franklin.css` and remove the `.katex-display::after` block.
-You can also build a simple way to disable all numbering inside a specified `@@` div 
-(see [div blocks](/syntax/divs-commands/#div_blocks))
-
-```markdown
-This is numbered:
-$$ 1+1 = 2 $$
-
-This isn't:
-
-@@no-number
-$$ 2+2 = 4 $$
-and
-$$ 3+3 = 7-1 $$
-@@
-
-Numbered again:
-$$ 7 + 1 = 8 $$
-```
+\note{This is currently only available when you're using KaTeX for maths.}
+
+Use the environment `equation*`, `align*`, `aligned*` or `eqnarray*`. Alternatively, use `\nonumber{...your equation...}`.
+
+You will have to make sure that your CSS sheet contains the following rule:
 
-by adding in the CSS:
 ```css
-.no-number .katex-display::after {
+.nonumber .katex-display::after {
   counter-increment: nothing;
   content: "";
 }
 ```
 
-And possibly [define a command](/syntax/divs-commands/#latex-like_commands) in `config.md`:\
-```markdown
-\newcommand{\nalign}[1]{@@no-number \begin{align}#1\end{align}@@}
-```
-if you feel it is more convenient to write `\nalign{3+3 = 6}`.
+So for instance using `\begin{align*}...\end{align*}`:
+
+\begin{align*}
+    x &= 3 \\
+    y &= 4
+\end{align*}
+
+Or using `\nonumber{$$ ... $$}`:
+
+\nonumber{
+$$
+    x = 5
+$$
+}
+
+Recall that numbered equations can be referred to via `\eqref`:
+
+$$
+x = 14 \label{eqabc}
+$$
+
+like this: \eqref{eqabc}.
 
 
 ## Code
diff --git a/src/converter/latex/io.jl b/src/converter/latex/io.jl
index 22271d8ba..829034b6a 100644
--- a/src/converter/latex/io.jl
+++ b/src/converter/latex/io.jl
@@ -206,7 +206,7 @@ function lx_tableinput(lxc::LxCom, _)
 end
 
 """
-    \\liteate{...}
+    \\literate{...}
 
 Resolve a `\\literate{rpath}` (find a literate script and insert it).
 """
@@ -223,3 +223,13 @@ function lx_literate(lxc::LxCom, lxd::Vector{LxDef})
     # then reprocess
     return reprocess(read(opath, String), lxd, nostripp=true)
 end
+
+"""
+    \\nonumber{...}
+
+Suppress the displaying of a number.
+"""
+function lx_nonumber(c, lxd)
+    PAGE_EQREFS[PAGE_EQREFS_COUNTER] -= 1
+    return reprocess("@@nonumber " * content(c.braces[1]) * "@@", lxd)
+end
diff --git a/src/converter/latex/objects.jl b/src/converter/latex/objects.jl
index e125d5ccb..9722eac88 100644
--- a/src/converter/latex/objects.jl
+++ b/src/converter/latex/objects.jl
@@ -32,6 +32,9 @@ const LX_INTERNAL_COMMANDS = [
     lxd("style",           2, "~~~<span style=\"!#1\">~~~!#2~~~</span>~~~"),
     lxd("tableofcontents", 0, "\\toc"),
     lxd("codeoutput",      1, "\\output{#1}"), # \codeoutput{rpath}
+    # ------------------
+    # other
+    lxd("nonumber", 1),
     ]
 
 """
@@ -42,10 +45,14 @@ Convenience function to create pairs (envdname => simple envdef)
 lxe(n, k, d=Pair("", "")) = n => LxDef(n, k, d)
 
 const LX_INTERNAL_ENVIRONMENTS = [
-    lxe("equation", 0, raw"\[" => raw"\]"),
-    lxe("align",    0, raw"\[\begin{aligned}"    => raw"\end{aligned}\]"),
-    lxe("aligned",  0, raw"\[\begin{aligned}"    => raw"\end{aligned}\]"),
-    lxe("eqnarray", 0, raw"\[\begin{array}{rcl}" => raw"\end{array}\]"),
+    lxe("equation",  0, raw"\["           => raw"\]"),
+    lxe("equation*", 0, raw"\nonumber{\[" => raw"\]}"),
+    lxe("align",     0, raw"\[\begin{aligned}"              => raw"\end{aligned}\]"),
+    lxe("align*",    0, raw"\nonumber{\[\begin{aligned}"    => raw"\end{aligned}\]}"),
+    lxe("aligned",   0, raw"\[\begin{aligned}"              => raw"\end{aligned}\]"),
+    lxe("aligned*",  0, raw"\nonumber{\[\begin{aligned}"    => raw"\end{aligned}\]}"),
+    lxe("eqnarray",  0, raw"\[\begin{array}{rcl}"           => raw"\end{array}\]"),
+    lxe("eqnarray*", 0, raw"\nonumber{\[\begin{array}{rcl}" => raw"\end{array}\]}")
     ]