Add semantic block parser and PDF export

scripts/pandoc-filters/semantic-blocks.lua

@@ -0,0 +1,131 @@
+local env_types = {
+  theorem = true,
+  lemma = true,
+  proposition = true,
+  corollary = true,
+  definition = true,
+  example = true,
+  remark = true,
+  proof = true,
+}
+
+local function has_class(el, class_name)
+  for _, value in ipairs(el.classes) do
+    if value == class_name then
+      return true
+    end
+  end
+  return false
+end
+
+local function first_env_class(el)
+  for _, value in ipairs(el.classes) do
+    if env_types[value] then
+      return value
+    end
+  end
+  return nil
+end
+
+local function latex_escape(value)
+  value = tostring(value or "")
+  value = value:gsub("\\", "\\textbackslash{}")
+  value = value:gsub("([{}%%$&#_])", "\\%1")
+  value = value:gsub("%^", "\\textasciicircum{}")
+  value = value:gsub("~", "\\textasciitilde{}")
+  return value
+end
+
+local function internal_link_to_cref(el)
+  if FORMAT:match("latex") and el.target:sub(1, 1) == "#" then
+    local label = el.target:sub(2)
+    if label ~= "" then
+      return pandoc.RawInline("latex", "\\cref{" .. label .. "}")
+    end
+  end
+  return nil
+end
+
+local function markdown_to_latex(markdown)
+  local doc = pandoc.read(
+    markdown or "",
+    "markdown+fenced_code_attributes+tex_math_dollars+tex_math_single_backslash+footnotes+raw_html"
+  )
+  doc = doc:walk({ Link = internal_link_to_cref })
+  return pandoc.write(doc, "latex")
+end
+
+local function label_line(label)
+  if label and label ~= "" then
+    return "\\label{" .. label .. "}\n"
+  end
+  return ""
+end
+
+local function interactive_to_latex(el)
+  local label = el.identifier
+  local caption = el.attributes.caption or el.attributes.title or ""
+  local fallback = el.attributes.pdf or el.attributes.fallback or el.text
+  local fallback_latex = markdown_to_latex(fallback)
+  local caption_line = ""
+
+  if caption ~= "" then
+    caption_line = "\\caption{" .. latex_escape(caption) .. "}\n"
+  end
+
+  return pandoc.RawBlock(
+    "latex",
+    table.concat({
+      "\\begin{figure}[htbp]\n",
+      "\\centering\n",
+      "\\fbox{\\begin{minipage}{0.86\\linewidth}\n",
+      fallback_latex,
+      "\n\\end{minipage}}\n",
+      caption_line,
+      label_line(label),
+      "\\end{figure}",
+    })
+  )
+end
+
+local function env_to_latex(el)
+  local env_type = el.attributes.type or first_env_class(el)
+  if not env_type or not env_types[env_type] then
+    return nil
+  end
+
+  local title = el.attributes.title or el.attributes.name or ""
+  local begin_env = "\\begin{" .. env_type .. "}"
+  if title ~= "" then
+    begin_env = begin_env .. "[" .. latex_escape(title) .. "]"
+  end
+
+  return pandoc.RawBlock(
+    "latex",
+    table.concat({
+      begin_env,
+      "\n",
+      label_line(el.identifier),
+      markdown_to_latex(el.text),
+      "\n\\end{",
+      env_type,
+      "}",
+    })
+  )
+end
+
+function CodeBlock(el)
+  if FORMAT:match("latex") and has_class(el, "interactive") then
+    return interactive_to_latex(el)
+  end
+
+  if FORMAT:match("latex") and (has_class(el, "env") or has_class(el, "latex-env") or first_env_class(el)) then
+    return env_to_latex(el)
+  end
+
+  return nil
+end
+
+function Link(el)
+  return internal_link_to_cref(el)
+end