# Missing Features / Limitations

* [x] **Heading varieties** : No support for Setext headings (`===` /`---`  underlines), optional closing `#` , heading IDs with duplicate handling, nor preservation of a top-level `h1`  (current logic drops the first `#`  heading unconditionally).
* [x] **Paragraph semantics** : Paragraph building treats every non-empty line as a `<p>`  and inserts `<br>`  between, breaking standard markdown rules about blank lines, lazy continuation lines, and container blocks (lists, blockquotes).
* [x] **List handling** : Regex conversion expects isolated list lines and wraps each `<li>`  in its own `<ul>` /`<ol>` , so multi-line items, nested lists, tight/loose spacing, ordered list numbering, and bullet-marker variations (`+` , `-` , `*` ) are all mis-rendered. Task list logic converts any single line but cannot coexist with proper list structure.
* [x] **Blockquotes** : Generic blockquote replacement only grabs one line after `>` , losing nested content, lazy continuations, and mixed blocks (e.g., lists inside blockquotes).
* [x] **Emphasis rules** : Simple replacements for `*` /`**` /`~~`  ignore underscores, intraword emphasis rules, nesting, escaping, or edge cases like `***bold and italic***` .
* [x] **Links & images** : Only processes inline destination syntax with absolute URLs. Missing relative path support, reference-style links (`[ref][]` ), angle-bracket autolinks `<https://>` , image titles without URL, and no differentiation between external and internal links beyond scheme check.
* [x] **Reference definitions** : No parsing for link/image reference definitions at block level (`[id]: URL "title"` ), so references cannot resolve.
* [x] **Footnotes & definitions** : Lacks footnote syntax (`[^1]` ) and corresponding rendering.
* [x] **HTML blocks/inlines** : Raw HTML either stripped or double-escaped; there’s no logic to allow HTML blocks or disallowed raw HTML rules from GFM.
* [x] **Escaping** : Backslash escapes for punctuation, entity references, and escaping special characters are unsupported;\n  escapeHtml() only runs on select segments.
* [x] **Hard/soft line breaks** : Treats every newline as `<br>` , ignoring two-space hard break convention and soft break behavior.
* [x] **Performance/robustness** : Repeated global regex replacements can introduce double-wrapping, miss overlapping patterns, and make escaping fragile. Lacking overall markdown parsing state leads to conflicts (e.g., `#hashtag`  inside code blocks already removed via placeholder but inline code restoration may still break hashtags).
* [x] **Inline code spans** : Handles only single-line ``code`` sequences and does not honor backtick escapes, trim rules, or multiple backtick fences.
* [x] **Tables (GFM extensions)** : Only pipe tables supported. Missing support for inline markdown within cells, row spans, or text alignment fallback when separators are malformed.
* [x] **Code blocks** : Indented code blocks (4 spaces) not detected; fenced blocks limited to triple backticks, no tilde fences (`~~~`), info string handling is case-sensitive, and language fallback doesn’t respect GFM spec (e.g., unrecognized language should leave raw text).
* [x] **Math/LaTeX** : `$$…$$` replaced with a static placeholder; inline math `$…$`, `\(` `\)` not handled.
* [x] **Frontmatter** : YAML frontmatter stripping not present; if notes contain `---` blocks at top they flow into paragraph logic.
* [x] **Internationalization** : slugify() strips non-word characters, removing accents rather than transliterating; may produce empty IDs for non-Latin headings.