Calc2

frontend/app/utils/markdown.ts

@@ -118,6 +118,76 @@ function wikilinkRule(state: StateInline, silent: boolean): boolean {
 
 md.inline.ruler.before('link', 'wikilink', wikilinkRule)
 
+/**
+ * Math callout blocks: a fenced block tagged with one of these keywords
+ * (```theorem, ```example, ...) renders as a blockquote-styled box with the
+ * keyword's colour on its left edge instead of as code. The body is parsed as
+ * ordinary Markdown; any text after the keyword titles the box
+ * (```theorem Pythagoras). Colours live in _tokens.scss, shapes in _prose.scss.
+ * The label names the kind of statement *the article* makes, so it is written
+ * in the article's language (carried through the render env) — the reader's
+ * interface language never touches the page's text. Unknown languages keep English.
+ */
+type CalloutKind = 'example' | 'theorem' | 'corollary' | 'definition' | 'proof' | 'proposition' | 'lemma'
+
+const CALLOUT_EN: Record<CalloutKind, string> = {
+  example: 'Example',
+  theorem: 'Theorem',
+  corollary: 'Corollary',
+  definition: 'Definition',
+  proof: 'Proof',
+  proposition: 'Proposition',
+  lemma: 'Lemma',
+}
+
+const CALLOUT_LABELS: Record<string, Partial<Record<CalloutKind, string>>> = {
+  fr: { theorem: 'Théorème', corollary: 'Corollaire', definition: 'Définition', proof: 'Démonstration', example: 'Exemple', lemma: 'Lemme' },
+  de: { theorem: 'Satz', corollary: 'Korollar', proof: 'Beweis', example: 'Beispiel' },
+  es: { theorem: 'Teorema', corollary: 'Corolario', definition: 'Definición', proof: 'Demostración', proposition: 'Proposición', example: 'Ejemplo', lemma: 'Lema' },
+  ca: { theorem: 'Teorema', corollary: 'Corol·lari', definition: 'Definició', proof: 'Demostració', proposition: 'Proposició', example: 'Exemple', lemma: 'Lema' },
+  pt: { theorem: 'Teorema', corollary: 'Corolário', definition: 'Definição', proof: 'Demonstração', proposition: 'Proposição', example: 'Exemplo', lemma: 'Lema' },
+  it: { theorem: 'Teorema', corollary: 'Corollario', definition: 'Definizione', proof: 'Dimostrazione', proposition: 'Proposizione', example: 'Esempio' },
+  nl: { theorem: 'Stelling', corollary: 'Gevolg', proof: 'Bewijs', example: 'Voorbeeld', definition: 'Definitie', proposition: 'Propositie' },
+  pl: { theorem: 'Twierdzenie', corollary: 'Wniosek', definition: 'Definicja', proof: 'Dowód', proposition: 'Propozycja', example: 'Przykład', lemma: 'Lemat' },
+  ru: { theorem: 'Теорема', corollary: 'Следствие', definition: 'Определение', proof: 'Доказательство', proposition: 'Утверждение', example: 'Пример', lemma: 'Лемма' },
+  uk: { theorem: 'Теорема', corollary: 'Наслідок', definition: 'Означення', proof: 'Доведення', proposition: 'Твердження', example: 'Приклад', lemma: 'Лема' },
+  tr: { theorem: 'Teorem', corollary: 'Sonuç', definition: 'Tanım', proof: 'İspat', proposition: 'Önerme', example: 'Örnek' },
+  ar: { theorem: 'مبرهنة', corollary: 'نتيجة', definition: 'تعريف', proof: 'برهان', proposition: 'قضية', example: 'مثال', lemma: 'ليما' },
+  fa: { theorem: 'قضیه', corollary: 'نتیجه', definition: 'تعریف', proof: 'اثبات', proposition: 'گزاره', example: 'مثال', lemma: 'لم' },
+  hi: { theorem: 'प्रमेय', corollary: 'निष्कर्ष', definition: 'परिभाषा', proof: 'प्रमाण', example: 'उदाहरण', proposition: 'कथन', lemma: 'उपप्रमेय' },
+  zh: { theorem: '定理', corollary: '推论', definition: '定义', proof: '证明', proposition: '命题', lemma: '引理', example: '例' },
+  ja: { theorem: '定理', corollary: '系', definition: '定義', proof: '証明', proposition: '命題', lemma: '補題', example: '例' },
+  ko: { theorem: '정리', corollary: '계', definition: '정의', proof: '증명', proposition: '명제', lemma: '보조정리', example: '예' },
+}
+
+function isCalloutWord(word: string): word is CalloutKind {
+  return Object.hasOwn(CALLOUT_EN, word)
+}
+
+const defaultFence = md.renderer.rules.fence!.bind(md.renderer)
+
+md.renderer.rules.fence = (tokens, idx, options, env, self) => {
+  const token = tokens[idx]!
+  const info = token.info.trim()
+  const space = info.search(/\s/)
+  const word = (space === -1 ? info : info.slice(0, space)).toLowerCase()
+  if (!isCalloutWord(word)) return defaultFence(tokens, idx, options, env, self)
+
+  // renderMarkdown hands the article's language through the env; anything
+  // rendered without one (or in a language not listed above) keeps English
+  const lang = (env as { articleLanguage?: unknown } | undefined)?.articleLanguage
+  const labels = (typeof lang === 'string' && CALLOUT_LABELS[lang.trim().toLowerCase()]) || CALLOUT_EN
+  const kind = labels[word] ?? CALLOUT_EN[word]
+  const title = space === -1 ? '' : info.slice(space + 1).trim()
+  const label = title ? `${kind} — ${md.utils.escapeHtml(title)}` : kind
+  const body = md.render(token.content, env).trim()
+  // a native <details> makes the label row the toggle: it works on the first
+  // paint and from the keyboard, and MarkdownView animates the fold; every
+  // box starts open. The body is one wrapper so the fold has a single thing
+  // to measure and shrink.
+  return `<blockquote class="md-box md-box--${word}"><details open><summary class="md-box-title">${label}</summary><div class="md-box-body">${body}</div></details></blockquote>\n`
+}
+
 /** Best-effort plain text of an inline token (for TOC labels). */
 function inlineText(inline: Token): string {
   let out = ''
@@ -144,8 +214,11 @@ const sanitizeConfig = {
  * `namespace` prefixes the heading ids (the reader passes the article slug),
  * so that the articles open side by side never hand the document two
  * headings with the same id.
+ *
+ * `language` is the article's own language — callout boxes (```theorem, …)
+ * write their labels in it, never in the interface language.
  */
-export function renderMarkdown(source: string, namespace?: string): RenderedMarkdown {
+export function renderMarkdown(source: string, namespace?: string, language?: string): RenderedMarkdown {
   const src = source ?? ''
   const tokens = md.parse(src, {})
   const toc: TocEntry[] = []
@@ -169,7 +242,7 @@ export function renderMarkdown(source: string, namespace?: string): RenderedMark
     if (level >= 2 && level <= 3) toc.push({ id: `${prefix}${id}`, text, level })
   }
 
-  const raw = md.renderer.render(tokens, md.options, {})
+  const raw = md.renderer.render(tokens, md.options, { articleLanguage: language })
   const html = DOMPurify.sanitize(raw, sanitizeConfig) as unknown as string
   return { html, toc }
 }