Fix native escaped backtick rendering. (#249)

Instead of having a dedicated class, we can just fix the AST when
processing escaped backticks.

Author: bluegate010

build.sh

@@ -771,7 +771,7 @@ do_latex() {
 		--standalone
 		--highlight-style=${SYNTAX_HIGHLIGHT_STYLE}
 		--template=${TEMPLATE_PDF}
-		--lua-filter=render-helpers.lua
+		--lua-filter=fix-latex-backticks.lua
 		--lua-filter=convert-diagrams.lua
 		--lua-filter=convert-images.lua
 		--lua-filter=center-images.lua
@@ -882,7 +882,6 @@ do_docx() {
 	cmd=(pandoc
 		--embed-resources
 		--standalone
-		--lua-filter=render-helpers.lua
 		--lua-filter=convert-diagrams.lua
 		--lua-filter=convert-images.lua
 		--lua-filter=parse-html.lua
@@ -926,7 +925,6 @@ do_html() {
 		--standalone
 		--template=${TEMPLATE_HTML}
 		${HTML_STYLESHEET_ARGS}
-		--lua-filter=render-helpers.lua
 		--lua-filter=convert-diagrams.lua
 		--lua-filter=parse-html.lua
 		--lua-filter=apply-classes-to-tables.lua

filter/fix-latex-backticks.lua

@@ -0,0 +1,30 @@
+-- Correct backtick rendering in Latex. Without this, escaped backticks are displayed as curly open single quote marks.
+
+function Str(el)
+  local new_inlines = {}
+  local current_text = ""
+
+  if FORMAT ~= "latex" or not el.text:match("`") then
+    return el
+  end
+
+  for i = 1, #el.text do
+    local char = el.text:sub(i, i)
+
+    if char == "`" then
+      if current_text ~= "" then
+        table.insert(new_inlines, pandoc.Str(current_text))
+        current_text = ""
+      end
+      table.insert(new_inlines, pandoc.RawInline('latex', '\\textasciigrave{}'))
+    else
+      current_text = current_text .. char
+    end
+  end
+
+  if current_text ~= "" then
+    table.insert(new_inlines, pandoc.Str(current_text))
+  end
+
+  return new_inlines
+end

filter/render-helpers.lua

@@ -1460,16 +1460,6 @@ Carl->>Bob: Goodbye
 Bob->>Alice: Goodbye
 ```
 
-## Helper classes
-
-To wrap a word in backticks that render as normal text, you can use the following syntax:
-
-```md
-[These words]{.btick} are in backticks.
-```
-
-[These words]{.btick} are in backticks.
-
 ## TCG Storage Workgroup Customizations
 
 TCG Storage committee uses command `MethodsOrUID` to render Names of methods and UIDs in \MethodsOrUID{Courier New font}.