markdown-it/lib/common/html_re.js

// Regexps to match html elements

'use strict';

var attr_name     = '[a-zA-Z_:][a-zA-Z0-9:._-]*';

var unquoted      = '[^"\'=<>`\\x00-\\x20]+';
var single_quoted = "'[^']*'";
var double_quoted = '"[^"]*"';

var attr_value  = '(?:' + unquoted + '|' + single_quoted + '|' + double_quoted + ')';

var attribute   = '(?:\\s+' + attr_name + '(?:\\s*=\\s*' + attr_value + ')?)';

var open_tag    = '<[A-Za-z][A-Za-z0-9\\-]*' + attribute + '*\\s*\\/?>';

var close_tag   = '<\\/[A-Za-z][A-Za-z0-9\\-]*\\s*>';
var comment     = '<!---->|<!--(?:-?[^>-])(?:-?[^-])*-->';
var processing  = '<[?].*?[?]>';
var declaration = '<![A-Z]+\\s+[^>]*>';
var cdata       = '<!\\[CDATA\\[[\\s\\S]*?\\]\\]>';

var HTML_TAG_RE = new RegExp('^(?:' + open_tag + '|' + close_tag + '|' + comment +
                        '|' + processing + '|' + declaration + '|' + cdata + ')');

module.exports.HTML_TAG_RE = HTML_TAG_RE;