(function (Prism) {

	var specialEscape = {
		pattern: /\\[\\(){}[\]^$+*?|.]/,
		alias: 'escape'
	};
	var escape = /\\(?:x[\da-fA-F]{2}|u[\da-fA-F]{4}|u\{[\da-fA-F]+\}|c[a-zA-Z]|0[0-7]{0,2}|[123][0-7]{2}|.)/
	var charClass = /\\[wsd]|\.|\\p{[^{}]+}/i

	var rangeChar = '(?:[^\\\\-]|' + escape.source + ')';
	var range = RegExp(rangeChar + '-' + rangeChar);

	// the name of a capturing group
	var groupName = {
		pattern: /(<|')[^<>']+(?=[>']$)/,
		lookbehind: true,
		alias: 'variable'
	};

	var backreference = [
		/\\(?![123][0-7]{2})[1-9]/, // a backreference which is not an octal escape
		{
			pattern: /\\k<[^<>']+>/,
			inside: {
				'group-name': groupName
			}
		}
	];

	Prism.languages.regex = {
		'charset': {
			pattern: /((?:^|[^\\])(?:\\\\)*)\[(?:[^\\\]]|\\[\s\S])*\]/,
			lookbehind: true,
			inside: {
				'charset-negation': {
					pattern: /(^\[)\^/,
					lookbehind: true,
				},
				'charset-punctuation': /^\[|\]$/,
				'range': {
					pattern: range,
					inside: {
						'escape': escape,
						'range-punctuation': /-/
					}
				},
				'special-escape': specialEscape,
				'charclass': charClass,
				'backreference': backreference,
				'escape': escape
			}
		},
		'special-escape': specialEscape,
		'charclass': charClass,
		'backreference': backreference,
		'anchor': /[$^]|\\[ABbGZz]/,
		'escape': escape,
		'group': [
			{
				// https://docs.oracle.com/javase/10/docs/api/java/util/regex/Pattern.html
				// https://docs.microsoft.com/en-us/dotnet/standard/base-types/regular-expression-language-quick-reference?view=netframework-4.7.2#grouping-constructs

				// (), (?<name>), (?'name'), (?>), (?:), (?=), (?!), (?<=), (?<!), (?is-m), (?i-m:)
				pattern: /\((?:\?(?:<[^<>']+>|'[^<>']+'|[>:]|<?[=!]|[idmnsuxU]+(?:-[idmnsuxU]+)?:?))?/,
				inside: {
					'group-name': groupName
				}
			},
			/\)/
		],
		'quantifier': /[+*?]|\{(?:\d+,?\d*)\}/,
		'alternation': /\|/
	};


	[
		'actionscript',
		'coffescript',
		'flow',
		'javascript',
		'typescript',
		'vala'
	].forEach(function (lang) {
		var grammar = Prism.languages[lang];
		if (grammar) {
			grammar['regex'].inside = {
				'regex-flags': /[a-z]+$/,
				'regex-delimiter': /^\/|\/$/,
				'language-regex': {
					pattern: /[\s\S]+/,
					inside: Prism.languages.regex
				}
			};
		}
	});

}(Prism))