Function cachedLexer

src/components/Markdown.tsx:72–117

(content: string)

  return MD_SYNTAX_RE.test(s.length > 500 ? s.slice(0, 500) : s);
}
function cachedLexer(content: string): {
  tokens: Token[];
  cacheKey?: string;
} {
  // Fast path: plain text with no markdown syntax → single paragraph token.
  // Skips marked.lexer's full GFM parse (~3ms on long content). Not cached —
  // reconstruction is a single object allocation, and caching would retain
  // 4× content in raw/text fields plus the hash key for zero benefit.
  if (!hasMarkdownSyntax(content)) {
    return {
      tokens: [{
        type: 'paragraph',
        raw: content,
        text: content,
        tokens: [{
          type: 'text',
          raw: content,
          text: content
        }]
      } as Token]
    };
  }
  const key = hashContent(content);
  const hit = tokenCache.get(key);
  if (hit) {
    // Promote to MRU — without this the eviction is FIFO (scrolling back to
    // an early message evicts the very item you're looking at).
    tokenCache.delete(key);
    tokenCache.set(key, hit);
    return {
      tokens: hit,
      cacheKey: key
    };
  }
  const tokens = lexMarkdownPreservingPreformattedDiagrams(content);
  if (tokenCache.size >= TOKEN_CACHE_MAX) {
    // LRU-ish: drop oldest. Map preserves insertion order.
    const first = tokenCache.keys().next().value;
    if (first !== undefined) tokenCache.delete(first);
  }
  tokenCache.set(key, tokens);
  return {
    tokens,
    cacheKey: key
  };
}

function buildMarkdownRenderBlocks(tokens: Token[], theme: string, highlight: CliHighlight | null): MarkdownRenderBlock[] {
  const buildStartMs = nowMs();