// Regexps to match html elements

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

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

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

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

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

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

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

export { HTML_TAG_RE, HTML_OPEN_CLOSE_TAG_RE };