mdream 1.6.0

// Constants converted from const.ts

pub const TAG_HTML: u8 = 0;
pub const TAG_HEAD: u8 = 1;
pub const TAG_DETAILS: u8 = 2;
pub const TAG_SUMMARY: u8 = 3;
pub const TAG_TITLE: u8 = 4;
pub const TAG_META: u8 = 5;
pub const TAG_BR: u8 = 6;
pub const TAG_H1: u8 = 7;
pub const TAG_H2: u8 = 8;
pub const TAG_H3: u8 = 9;
pub const TAG_H4: u8 = 10;
pub const TAG_H5: u8 = 11;
pub const TAG_H6: u8 = 12;
pub const TAG_HR: u8 = 13;
pub const TAG_STRONG: u8 = 14;
pub const TAG_B: u8 = 15;
pub const TAG_EM: u8 = 16;
pub const TAG_I: u8 = 17;
pub const TAG_DEL: u8 = 18;
pub const TAG_SUB: u8 = 19;
pub const TAG_SUP: u8 = 20;
pub const TAG_INS: u8 = 21;
pub const TAG_BLOCKQUOTE: u8 = 22;
pub const TAG_CODE: u8 = 23;
pub const TAG_UL: u8 = 24;
pub const TAG_LI: u8 = 25;
pub const TAG_A: u8 = 26;
pub const TAG_IMG: u8 = 27;
pub const TAG_TABLE: u8 = 28;
pub const TAG_THEAD: u8 = 29;
pub const TAG_TR: u8 = 30;
pub const TAG_TH: u8 = 31;
pub const TAG_TD: u8 = 32;
pub const TAG_OL: u8 = 33;
pub const TAG_PRE: u8 = 34;
pub const TAG_P: u8 = 35;
pub const TAG_DIV: u8 = 36;
pub const TAG_SPAN: u8 = 37;
pub const TAG_TBODY: u8 = 38;
pub const TAG_TFOOT: u8 = 39;
pub const TAG_FORM: u8 = 40;
pub const TAG_NAV: u8 = 41;
pub const TAG_LABEL: u8 = 42;
pub const TAG_BUTTON: u8 = 43;
pub const TAG_BODY: u8 = 44;
pub const TAG_CENTER: u8 = 45;
pub const TAG_KBD: u8 = 46;
pub const TAG_FOOTER: u8 = 47;
pub const TAG_PATH: u8 = 48;
pub const TAG_SVG: u8 = 49;
pub const TAG_ARTICLE: u8 = 50;
pub const TAG_SECTION: u8 = 51;
pub const TAG_SCRIPT: u8 = 52;
pub const TAG_STYLE: u8 = 53;
pub const TAG_LINK: u8 = 54;
pub const TAG_AREA: u8 = 55;
pub const TAG_BASE: u8 = 56;
pub const TAG_COL: u8 = 57;
pub const TAG_EMBED: u8 = 58;
pub const TAG_INPUT: u8 = 59;
pub const TAG_KEYGEN: u8 = 60;
pub const TAG_PARAM: u8 = 61;
pub const TAG_SOURCE: u8 = 62;
pub const TAG_TRACK: u8 = 63;
pub const TAG_WBR: u8 = 64;
pub const TAG_SELECT: u8 = 65;
pub const TAG_TEXTAREA: u8 = 66;
pub const TAG_OPTION: u8 = 67;
pub const TAG_FIELDSET: u8 = 68;
pub const TAG_LEGEND: u8 = 69;
pub const TAG_AUDIO: u8 = 70;
pub const TAG_VIDEO: u8 = 71;
pub const TAG_CANVAS: u8 = 72;
pub const TAG_IFRAME: u8 = 73;
pub const TAG_MAP: u8 = 74;
pub const TAG_DIALOG: u8 = 75;
pub const TAG_METER: u8 = 76;
pub const TAG_PROGRESS: u8 = 77;
pub const TAG_TEMPLATE: u8 = 78;
pub const TAG_ABBR: u8 = 79;
pub const TAG_MARK: u8 = 80;
pub const TAG_Q: u8 = 81;
pub const TAG_SAMP: u8 = 82;
pub const TAG_SMALL: u8 = 83;
pub const TAG_NOSCRIPT: u8 = 84;
pub const TAG_NOFRAMES: u8 = 85;
pub const TAG_XMP: u8 = 86;
pub const TAG_PLAINTEXT: u8 = 87;
pub const TAG_ASIDE: u8 = 88;
pub const TAG_U: u8 = 89;
pub const TAG_CITE: u8 = 90;
pub const TAG_DFN: u8 = 91;
pub const TAG_VAR: u8 = 92;
pub const TAG_TIME: u8 = 93;
pub const TAG_BDO: u8 = 94;
pub const TAG_RUBY: u8 = 95;
pub const TAG_RT: u8 = 96;
pub const TAG_RP: u8 = 97;
pub const TAG_DD: u8 = 98;
pub const TAG_DT: u8 = 99;
pub const TAG_ADDRESS: u8 = 100;
pub const TAG_DL: u8 = 101;
pub const TAG_FIGURE: u8 = 102;
pub const TAG_OBJECT: u8 = 103;
pub const TAG_MAIN: u8 = 104;
pub const TAG_HEADER: u8 = 105;
pub const TAG_FIGCAPTION: u8 = 106;
pub const TAG_CAPTION: u8 = 107;
pub const TAG_DATALIST: u8 = 108;
pub const TAG_OPTGROUP: u8 = 109;
pub const TAG_S: u8 = 110;
pub const TAG_STRIKE: u8 = 111;
pub const TAG_NOEMBED: u8 = 112;

pub const MAX_TAG_ID: usize = 113;

/// Reverse lookup: tag ID → static tag name string.
/// Avoids allocating a String for known tags.
pub static TAG_NAMES: [&str; MAX_TAG_ID] = {
  let mut names = [""; MAX_TAG_ID];
  names[TAG_HTML as usize] = "html";
  names[TAG_HEAD as usize] = "head";
  names[TAG_DETAILS as usize] = "details";
  names[TAG_SUMMARY as usize] = "summary";
  names[TAG_TITLE as usize] = "title";
  names[TAG_META as usize] = "meta";
  names[TAG_BR as usize] = "br";
  names[TAG_H1 as usize] = "h1";
  names[TAG_H2 as usize] = "h2";
  names[TAG_H3 as usize] = "h3";
  names[TAG_H4 as usize] = "h4";
  names[TAG_H5 as usize] = "h5";
  names[TAG_H6 as usize] = "h6";
  names[TAG_HR as usize] = "hr";
  names[TAG_STRONG as usize] = "strong";
  names[TAG_B as usize] = "b";
  names[TAG_EM as usize] = "em";
  names[TAG_I as usize] = "i";
  names[TAG_DEL as usize] = "del";
  names[TAG_S as usize] = "s";
  names[TAG_STRIKE as usize] = "strike";
  names[TAG_SUB as usize] = "sub";
  names[TAG_SUP as usize] = "sup";
  names[TAG_INS as usize] = "ins";
  names[TAG_BLOCKQUOTE as usize] = "blockquote";
  names[TAG_CODE as usize] = "code";
  names[TAG_UL as usize] = "ul";
  names[TAG_LI as usize] = "li";
  names[TAG_A as usize] = "a";
  names[TAG_IMG as usize] = "img";
  names[TAG_TABLE as usize] = "table";
  names[TAG_THEAD as usize] = "thead";
  names[TAG_TR as usize] = "tr";
  names[TAG_TH as usize] = "th";
  names[TAG_TD as usize] = "td";
  names[TAG_OL as usize] = "ol";
  names[TAG_PRE as usize] = "pre";
  names[TAG_P as usize] = "p";
  names[TAG_DIV as usize] = "div";
  names[TAG_SPAN as usize] = "span";
  names[TAG_TBODY as usize] = "tbody";
  names[TAG_TFOOT as usize] = "tfoot";
  names[TAG_FORM as usize] = "form";
  names[TAG_NAV as usize] = "nav";
  names[TAG_LABEL as usize] = "label";
  names[TAG_BUTTON as usize] = "button";
  names[TAG_BODY as usize] = "body";
  names[TAG_CENTER as usize] = "center";
  names[TAG_KBD as usize] = "kbd";
  names[TAG_FOOTER as usize] = "footer";
  names[TAG_PATH as usize] = "path";
  names[TAG_SVG as usize] = "svg";
  names[TAG_ARTICLE as usize] = "article";
  names[TAG_SECTION as usize] = "section";
  names[TAG_SCRIPT as usize] = "script";
  names[TAG_STYLE as usize] = "style";
  names[TAG_LINK as usize] = "link";
  names[TAG_AREA as usize] = "area";
  names[TAG_BASE as usize] = "base";
  names[TAG_COL as usize] = "col";
  names[TAG_EMBED as usize] = "embed";
  names[TAG_INPUT as usize] = "input";
  names[TAG_KEYGEN as usize] = "keygen";
  names[TAG_PARAM as usize] = "param";
  names[TAG_SOURCE as usize] = "source";
  names[TAG_TRACK as usize] = "track";
  names[TAG_WBR as usize] = "wbr";
  names[TAG_SELECT as usize] = "select";
  names[TAG_TEXTAREA as usize] = "textarea";
  names[TAG_OPTION as usize] = "option";
  names[TAG_FIELDSET as usize] = "fieldset";
  names[TAG_LEGEND as usize] = "legend";
  names[TAG_AUDIO as usize] = "audio";
  names[TAG_VIDEO as usize] = "video";
  names[TAG_CANVAS as usize] = "canvas";
  names[TAG_IFRAME as usize] = "iframe";
  names[TAG_MAP as usize] = "map";
  names[TAG_DIALOG as usize] = "dialog";
  names[TAG_METER as usize] = "meter";
  names[TAG_PROGRESS as usize] = "progress";
  names[TAG_TEMPLATE as usize] = "template";
  names[TAG_ABBR as usize] = "abbr";
  names[TAG_MARK as usize] = "mark";
  names[TAG_Q as usize] = "q";
  names[TAG_SAMP as usize] = "samp";
  names[TAG_SMALL as usize] = "small";
  names[TAG_NOSCRIPT as usize] = "noscript";
  names[TAG_NOFRAMES as usize] = "noframes";
  names[TAG_XMP as usize] = "xmp";
  names[TAG_PLAINTEXT as usize] = "plaintext";
  names[TAG_ASIDE as usize] = "aside";
  names[TAG_U as usize] = "u";
  names[TAG_CITE as usize] = "cite";
  names[TAG_DFN as usize] = "dfn";
  names[TAG_VAR as usize] = "var";
  names[TAG_TIME as usize] = "time";
  names[TAG_BDO as usize] = "bdo";
  names[TAG_RUBY as usize] = "ruby";
  names[TAG_RT as usize] = "rt";
  names[TAG_RP as usize] = "rp";
  names[TAG_DD as usize] = "dd";
  names[TAG_DT as usize] = "dt";
  names[TAG_ADDRESS as usize] = "address";
  names[TAG_DL as usize] = "dl";
  names[TAG_FIGURE as usize] = "figure";
  names[TAG_OBJECT as usize] = "object";
  names[TAG_MAIN as usize] = "main";
  names[TAG_HEADER as usize] = "header";
  names[TAG_FIGCAPTION as usize] = "figcaption";
  names[TAG_CAPTION as usize] = "caption";
  names[TAG_DATALIST as usize] = "datalist";
  names[TAG_OPTGROUP as usize] = "optgroup";
  names[TAG_NOEMBED as usize] = "noembed";
  names
};

pub const ELEMENT_NODE: u8 = 1;
pub const TEXT_NODE: u8 = 2;

/// Attribute bitmask: which attribute names a tag's rendering actually reads.
/// Each stored value costs an owned `String`, the dominant allocation during
/// parsing, yet a built-in tag reads at most three.
pub const ATTR_NONE: u16 = 0;
pub const ATTR_HREF: u16 = 1 << 0;
pub const ATTR_TITLE: u16 = 1 << 1;
pub const ATTR_ARIA_LABEL: u16 = 1 << 2;
pub const ATTR_SRC: u16 = 1 << 3;
pub const ATTR_ALT: u16 = 1 << 4;
pub const ATTR_CLASS: u16 = 1 << 5;
pub const ATTR_ALIGN: u16 = 1 << 6;
pub const ATTR_NAME: u16 = 1 << 7;
pub const ATTR_PROPERTY: u16 = 1 << 8;
pub const ATTR_CONTENT: u16 = 1 << 9;
pub const ATTR_START: u16 = 1 << 10;
pub const ATTR_COLSPAN: u16 = 1 << 11;
pub const ATTR_ALL: u16 = u16::MAX;

/// Case-insensitive, length-first so the common miss costs one compare.
#[inline]
pub(crate) fn attr_bit(name: &[u8]) -> u16 {
  match name.len() {
    3 => {
      if name.eq_ignore_ascii_case(b"alt") {
        ATTR_ALT
      } else if name.eq_ignore_ascii_case(b"src") {
        ATTR_SRC
      } else {
        ATTR_NONE
      }
    }
    4 => {
      if name.eq_ignore_ascii_case(b"href") {
        ATTR_HREF
      } else if name.eq_ignore_ascii_case(b"name") {
        ATTR_NAME
      } else {
        ATTR_NONE
      }
    }
    5 => {
      if name.eq_ignore_ascii_case(b"title") {
        ATTR_TITLE
      } else if name.eq_ignore_ascii_case(b"class") {
        ATTR_CLASS
      } else if name.eq_ignore_ascii_case(b"align") {
        ATTR_ALIGN
      } else if name.eq_ignore_ascii_case(b"start") {
        ATTR_START
      } else {
        ATTR_NONE
      }
    }
    7 => {
      if name.eq_ignore_ascii_case(b"content") {
        ATTR_CONTENT
      } else if name.eq_ignore_ascii_case(b"colspan") {
        ATTR_COLSPAN
      } else {
        ATTR_NONE
      }
    }
    8 => {
      if name.eq_ignore_ascii_case(b"property") {
        ATTR_PROPERTY
      } else {
        ATTR_NONE
      }
    }
    10 => {
      if name.eq_ignore_ascii_case(b"aria-label") {
        ATTR_ARIA_LABEL
      } else {
        ATTR_NONE
      }
    }
    _ => ATTR_NONE,
  }
}

pub const MARKDOWN_STRONG: &str = "**";
pub const MARKDOWN_EMPHASIS: &str = "*";
pub const MARKDOWN_STRIKETHROUGH: &str = "~~";
pub const MARKDOWN_CODE_BLOCK: &str = "```";
pub const MARKDOWN_INLINE_CODE: &str = "`";
pub const MARKDOWN_HORIZONTAL_RULE: &str = "---";
/// Rule sharing a line with a list marker: `- ---` is dashes and spaces only, so
/// the whole line is a thematic break and the item is lost. `*` cannot collide.
pub const MARKDOWN_HORIZONTAL_RULE_ALT: &str = "***";

pub const NO_SPACING: [u8; 2] = [0, 0];
pub const DEFAULT_BLOCK_SPACING: [u8; 2] = [2, 2];
pub const BLOCKQUOTE_SPACING: [u8; 2] = [2, 2];
pub const LIST_ITEM_SPACING: [u8; 2] = [1, 0];
pub const TABLE_ROW_SPACING: [u8; 2] = [0, 1];

pub const LT_CHAR: u8 = 60; // '<'
pub const GT_CHAR: u8 = 62; // '>'
pub const SLASH_CHAR: u8 = 47; // '/'
pub const EQUALS_CHAR: u8 = 61; // '='
pub const QUOTE_CHAR: u8 = 34; // '"'
pub const APOS_CHAR: u8 = 39; // '\''
pub const EXCLAMATION_CHAR: u8 = 33; // '!'
pub const QUESTION_CHAR: u8 = 63; // '?'
pub const AMPERSAND_CHAR: u8 = 38; // '&'
pub const BACKSLASH_CHAR: u8 = 92; // '\'
pub const DASH_CHAR: u8 = 45; // '-'
pub const SPACE_CHAR: u8 = 32; // ' '
pub const TAB_CHAR: u8 = 9; // '\t'
pub const NEWLINE_CHAR: u8 = 10; // '\n'
pub const CARRIAGE_RETURN_CHAR: u8 = 13; // '\r'
pub const BACKTICK_CHAR: u8 = 96; // '`'

/// Longest built-in HTML tag name (`blockquote`, `figcaption`); also the size
/// of the stack buffer used for the case-insensitive lookup.
const MAX_BUILTIN_TAG_LEN: usize = 10;

#[inline]
pub fn get_tag_id(name: &str) -> Option<u8> {
  get_tag_id_bytes(name.as_bytes())
}

/// Case-insensitive built-in tag lookup over raw bytes.
///
/// Lowercases ASCII into a stack-allocated `MAX_BUILTIN_TAG_LEN` buffer, avoiding the heap
/// allocation `name.to_ascii_lowercase()` would incur when the input contains
/// uppercase bytes. Returns `None` for any tag not in the built-in set.
#[inline]
pub fn get_tag_id_ci_bytes(name: &[u8]) -> Option<u8> {
  let len = name.len();
  if len == 0 || len > MAX_BUILTIN_TAG_LEN {
    return None;
  }
  // Nearly all real-world HTML already uses lowercase tag names. Avoid copying
  // and lowercasing the common case; retain the stack-buffer fallback for valid
  // mixed/uppercase HTML.
  if let Some(id) = get_tag_id_bytes(name) {
    return Some(id);
  }
  let mut buf = [0u8; MAX_BUILTIN_TAG_LEN];
  let mut i = 0;
  while i < len {
    buf[i] = name[i].to_ascii_lowercase();
    i += 1;
  }
  get_tag_id_bytes(&buf[..len])
}

/// Strict, case-sensitive tag name to ID lookup.
///
/// Matches the lowercase tag-name bytes directly against built-in byte-string
/// literals; the compiler lowers this to a length + first-byte decision tree
/// with fixed-size `memcmp` leaves. Returns `None` for any tag not in the
/// built-in set; callers can opt those tags into a rendering via `tagOverrides`.
#[inline]
fn get_tag_id_bytes(bytes: &[u8]) -> Option<u8> {
  Some(match bytes {
    b"figcaption" => TAG_FIGCAPTION,
    b"blockquote" => TAG_BLOCKQUOTE,
    b"plaintext" => TAG_PLAINTEXT,
    b"textarea" => TAG_TEXTAREA,
    b"template" => TAG_TEMPLATE,
    b"progress" => TAG_PROGRESS,
    b"noscript" => TAG_NOSCRIPT,
    b"noframes" => TAG_NOFRAMES,
    b"fieldset" => TAG_FIELDSET,
    b"summary" => TAG_SUMMARY,
    b"section" => TAG_SECTION,
    b"details" => TAG_DETAILS,
    b"caption" => TAG_CAPTION,
    b"datalist" => TAG_DATALIST,
    b"optgroup" => TAG_OPTGROUP,
    b"article" => TAG_ARTICLE,
    b"address" => TAG_ADDRESS,
    b"noembed" => TAG_NOEMBED,
    b"strong" => TAG_STRONG,
    b"source" => TAG_SOURCE,
    b"select" => TAG_SELECT,
    b"script" => TAG_SCRIPT,
    b"option" => TAG_OPTION,
    b"object" => TAG_OBJECT,
    b"legend" => TAG_LEGEND,
    b"keygen" => TAG_KEYGEN,
    b"iframe" => TAG_IFRAME,
    b"header" => TAG_HEADER,
    b"footer" => TAG_FOOTER,
    b"figure" => TAG_FIGURE,
    b"dialog" => TAG_DIALOG,
    b"center" => TAG_CENTER,
    b"canvas" => TAG_CANVAS,
    b"button" => TAG_BUTTON,
    b"strike" => TAG_STRIKE,
    b"video" => TAG_VIDEO,
    b"track" => TAG_TRACK,
    b"title" => TAG_TITLE,
    b"thead" => TAG_THEAD,
    b"tfoot" => TAG_TFOOT,
    b"tbody" => TAG_TBODY,
    b"table" => TAG_TABLE,
    b"style" => TAG_STYLE,
    b"small" => TAG_SMALL,
    b"param" => TAG_PARAM,
    b"meter" => TAG_METER,
    b"label" => TAG_LABEL,
    b"input" => TAG_INPUT,
    b"embed" => TAG_EMBED,
    b"audio" => TAG_AUDIO,
    b"aside" => TAG_ASIDE,
    b"time" => TAG_TIME,
    b"span" => TAG_SPAN,
    b"samp" => TAG_SAMP,
    b"ruby" => TAG_RUBY,
    b"path" => TAG_PATH,
    b"meta" => TAG_META,
    b"mark" => TAG_MARK,
    b"main" => TAG_MAIN,
    b"link" => TAG_LINK,
    b"html" => TAG_HTML,
    b"head" => TAG_HEAD,
    b"form" => TAG_FORM,
    b"code" => TAG_CODE,
    b"cite" => TAG_CITE,
    b"body" => TAG_BODY,
    b"base" => TAG_BASE,
    b"area" => TAG_AREA,
    b"abbr" => TAG_ABBR,
    b"xmp" => TAG_XMP,
    b"wbr" => TAG_WBR,
    b"var" => TAG_VAR,
    b"svg" => TAG_SVG,
    b"sup" => TAG_SUP,
    b"sub" => TAG_SUB,
    b"pre" => TAG_PRE,
    b"nav" => TAG_NAV,
    b"map" => TAG_MAP,
    b"kbd" => TAG_KBD,
    b"ins" => TAG_INS,
    b"img" => TAG_IMG,
    b"div" => TAG_DIV,
    b"dfn" => TAG_DFN,
    b"del" => TAG_DEL,
    b"col" => TAG_COL,
    b"bdo" => TAG_BDO,
    b"ul" => TAG_UL,
    b"tr" => TAG_TR,
    b"th" => TAG_TH,
    b"td" => TAG_TD,
    b"rt" => TAG_RT,
    b"rp" => TAG_RP,
    b"ol" => TAG_OL,
    b"li" => TAG_LI,
    b"hr" => TAG_HR,
    b"h6" => TAG_H6,
    b"h5" => TAG_H5,
    b"h4" => TAG_H4,
    b"h3" => TAG_H3,
    b"h2" => TAG_H2,
    b"h1" => TAG_H1,
    b"em" => TAG_EM,
    b"dt" => TAG_DT,
    b"dl" => TAG_DL,
    b"dd" => TAG_DD,
    b"br" => TAG_BR,
    b"u" => TAG_U,
    b"s" => TAG_S,
    b"q" => TAG_Q,
    b"p" => TAG_P,
    b"i" => TAG_I,
    b"b" => TAG_B,
    b"a" => TAG_A,
    _ => return None,
  })
}