# heading URL: /api/lexer/classifiers/heading/ Section: classifiers -------------------------------------------------------------------------------- heading - Patitas window.BENGAL_THEME_DEFAULTS = { appearance: 'light', palette: 'brown-bengal' }; window.Bengal = window.Bengal || {}; window.Bengal.enhanceBaseUrl = '/patitas/assets/js/enhancements'; window.Bengal.watchDom = true; window.Bengal.debug = false; window.Bengal.enhanceUrls = { 'toc': '/patitas/assets/js/enhancements/toc.632a9783.js', 'docs-nav': '/patitas/assets/js/enhancements/docs-nav.57e4b129.js', 'tabs': '/patitas/assets/js/enhancements/tabs.aac9e817.js', 'lightbox': '/patitas/assets/js/enhancements/lightbox.1ca22aa1.js', 'interactive': '/patitas/assets/js/enhancements/interactive.fc077855.js', 'mobile-nav': '/patitas/assets/js/enhancements/mobile-nav.d991657f.js', 'action-bar': '/patitas/assets/js/enhancements/action-bar.d62417f4.js', 'copy-link': '/patitas/assets/js/enhancements/copy-link.7d9a5c29.js', 'data-table': '/patitas/assets/js/enhancements/data-table.1f5bc1eb.js', 'lazy-loaders': '/patitas/assets/js/enhancements/lazy-loaders.a5c38245.js', 'holo': '/patitas/assets/js/enhancements/holo.ee13c841.js', 'link-previews': '/patitas/assets/js/enhancements/link-previews.8d906535.js' }; (function () { try { var defaults = window.BENGAL_THEME_DEFAULTS || { appearance: 'system', palette: '' }; var defaultAppearance = defaults.appearance; if (defaultAppearance === 'system') { defaultAppearance = (window.matchMedia && window.matchMedia('(prefers-color-scheme: dark)').matches) ? 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(storedTheme === 'system' ? defaultAppearance : storedTheme) : defaultAppearance; var palette = storedPalette ?? defaults.palette; document.documentElement.setAttribute('data-theme', theme); if (palette) { document.documentElement.setAttribute('data-palette', palette); } } catch (e) { document.documentElement.setAttribute('data-theme', 'light'); } })(); { "prerender": [ { "where": { "and": [ { "href_matches": "/docs/*" }, { "not": { "selector_matches": "[data-external], [target=_blank], .external" } } ] }, "eagerness": "conservative" } ], "prefetch": [ { "where": { "and": [ { "href_matches": "/*" }, { "not": { "selector_matches": "[data-external], [target=_blank], .external" } } ] }, "eagerness": "conservative" } ] } Skip to main content Magnifying Glass ESC Recent Clear Magnifying Glass No results for "" Start typing to search... ↑↓ Navigate ↵ Open ESC Close Powered by Lunr ฅᨐฅ DocumentationArrow ClockwiseGet StartedCodeSyntaxDirectivesStarburstExtendingBookmarkReferenceInfoAboutTroubleshootingReleasesDevGitHubPatitas API Reference Magnifying Glass Search ⌘K Palette Appearance Chevron Down Mode Monitor System Sun Light Moon Dark Palette Snow Lynx Brown Bengal Silver Bengal Charcoal Bengal Blue Bengal List ฅᨐฅ Magnifying Glass Search X Close Documentation Caret Down Arrow Clockwise Get Started Code Syntax Directives Starburst Extending Bookmark Reference Info About Troubleshooting Releases Dev Caret Down GitHub Patitas API Reference Palette Appearance Chevron Down Mode Monitor System Sun Light Moon Dark Palette Snow Lynx Brown Bengal Silver Bengal Charcoal Bengal Blue Bengal Patitas API Reference Caret Right Directives Caret Right Builtins admonition container dropdown tabs contracts decorator options protocol registry Caret Right Lexer Caret Right Classifiers directive fence footnote heading html link_ref list quote thematic Caret Right Scanners block directive fence html core modes Caret Right Parsing Caret Right Blocks Caret Right List blank_line indent item_blocks marker mixin nested trace types core directive footnote table Caret Right Inline core emphasis links match_registry special tokens charsets containers token_nav Caret Right Plugins autolinks footnotes math strikethrough table task_lists Caret Right Renderers html Caret Right Roles Caret Right Builtins formatting icons math reference protocol registry Caret Right Utils hashing logger text errors highlighting icons location nodes parser patitas protocols stringbuilder tokens LexerClassifiers ᗢ Caret Down Link Copy URL External Open LLM text Copy Copy LLM text Share with AI Ask Claude Ask ChatGPT Ask Gemini Ask Copilot Module lexer.classifiers.heading ATX heading classifier mixin. 1Class Classes HeadingClassifierMixin 2 ▼ Mixin providing ATX heading classification. Mixin providing ATX heading classification. Methods Internal Methods 2 ▼ _location_from 3 SourceLocation ▼ Get source location from saved position. Implemented by Lexer. def _location_from(self, start_pos: int, start_col: int | None = None, end_pos: int | None = None) -> SourceLocation Parameters Name Type Description start_pos — start_col — Default: None end_pos — Default: None Returns SourceLocation _try_classify_atx_heading 3 Token | None ▼ Try to classify content as ATX heading. ATX headings start with 1-6 # characte… def _try_classify_atx_heading(self, content: str, line_start: int, indent: int = 0) -> Token | None Try to classify content as ATX heading. ATX headings start with 1-6 # characters followed by space/tab/newline/end. Trailing # sequences are removed if preceded by space. Parameters Name Type Description content — Line content with leading whitespace stripped line_start — Position in source where line starts indent — Number of leading spaces (for line_indent) Default: 0 Returns Token | None Token if valid heading, None otherwise. ← Previous footnote Next → html List © 2026 Patitas built in ᓚᘏᗢ { "linkPreviews": { "enabled": true, "hoverDelay": 200, "hideDelay": 150, "showSection": true, "showReadingTime": true, "showWordCount": true, "showDate": true, "showTags": true, "maxTags": 3, "includeSelectors": [".prose"], "excludeSelectors": ["nav", ".toc", ".breadcrumb", ".pagination", ".card", "[class*='-card']", ".tab-nav", "[class*='-widget']", ".child-items", ".content-tiles"], "allowedHosts": [], "allowedSchemes": ["https"], "hostFailureThreshold": 3 } } window.BENGAL_LAZY_ASSETS = { tabulator: '/patitas/assets/js/tabulator.min.js', dataTable: '/patitas/assets/js/data-table.js', mermaidToolbar: '/patitas/assets/js/mermaid-toolbar.9de5abba.js', mermaidTheme: '/patitas/assets/js/mermaid-theme.344822c5.js', graphMinimap: '/patitas/assets/js/graph-minimap.ff04e939.js', graphContextual: '/patitas/assets/js/graph-contextual.355458ba.js' }; window.BENGAL_ICONS = { close: '/patitas/assets/icons/close.911d4fe1.svg', enlarge: '/patitas/assets/icons/enlarge.652035e5.svg', copy: '/patitas/assets/icons/copy.3d56e945.svg', 'download-svg': '/patitas/assets/icons/download.04f07e1b.svg', 'download-png': '/patitas/assets/icons/image.c34dfd40.svg', 'zoom-in': '/patitas/assets/icons/zoom-in.237b4a83.svg', 'zoom-out': '/patitas/assets/icons/zoom-out.38857c77.svg', reset: '/patitas/assets/icons/reset.d26dba29.svg' }; Arrow Up -------------------------------------------------------------------------------- Metadata: - Word Count: 709 - Reading Time: 4 minutes