if (typeof JSDOC == "undefined") JSDOC = {};

/**

	@constructor

*/

JSDOC.TokenStream = function(tokens) {

	this.tokens = (tokens || []);

	this.rewind();

}

/**

	@constructor

	@private

*/

function VoidToken(/**String*/type) {

	this.toString = function() {return "<VOID type=\""+type+"\">"};

	this.is = function(){return false;}

}

JSDOC.TokenStream.prototype.rewind = function() {

	this.cursor = -1;

}

/**

	@type JSDOC.Token

*/

JSDOC.TokenStream.prototype.look = function(/**Number*/n, /**Boolean*/considerWhitespace) {

	if (typeof n == "undefined") n = 0;

	if (considerWhitespace == true) {

		if (this.cursor+n < 0 || this.cursor+n > this.tokens.length) return {};

		return this.tokens[this.cursor+n];

	}

	else {

		var count = 0;

		var i = this.cursor;

		while (true) {

			if (i < 0) return new JSDOC.Token("", "VOID", "START_OF_STREAM");

			else if (i > this.tokens.length) return new JSDOC.Token("", "VOID", "END_OF_STREAM");

			if (i != this.cursor && (this.tokens[i] === undefined || this.tokens[i].is("WHIT"))) {

				if (n < 0) i--; else i++;

				continue;

			}

			if (count == Math.abs(n)) {

				return this.tokens[i];

			}

			count++;

			(n < 0)? i-- : i++;

		}

		return new JSDOC.Token("", "VOID", "STREAM_ERROR"); // because null isn't an object and caller always expects an object

	}

}

/**

	@type JSDOC.Token|JSDOC.Token[]

*/

JSDOC.TokenStream.prototype.next = function(/**Number*/howMany) {

	if (typeof howMany == "undefined") howMany = 1;

	if (howMany < 1) return null;

	var got = [];

	for (var i = 1; i <= howMany; i++) {

		if (this.cursor+i >= this.tokens.length) {

			return null;

		}

		got.push(this.tokens[this.cursor+i]);

	}

	this.cursor += howMany;

	if (howMany == 1) {

		return got[0];

	}

	else return got;

}

/**

	@type JSDOC.Token[]

*/

JSDOC.TokenStream.prototype.balance = function(/**String*/start, /**String*/stop) {

	if (!stop) stop = JSDOC.Lang.matching(start);

	var depth = 0;

	var got = [];

	var started = false;

	while ((token = this.look())) {

		if (token.is(start)) {

			depth++;

			started = true;

		}

		if (started) {

			got.push(token);

		}

		if (token.is(stop)) {

			depth--;

			if (depth == 0) return got;

		}

		if (!this.next()) break;

	}

}

JSDOC.TokenStream.prototype.getMatchingToken = function(/**String*/start, /**String*/stop) {

	var depth = 0;

	var cursor = this.cursor;

	if (!start) {

		start = JSDOC.Lang.matching(stop);

		depth = 1;

	}

	if (!stop) stop = JSDOC.Lang.matching(start);

	while ((token = this.tokens[cursor])) {

		if (token.is(start)) {

			depth++;

		}

		if (token.is(stop) && cursor) {

			depth--;

			if (depth == 0) return this.tokens[cursor];

		}

		cursor++;

	}

}

JSDOC.TokenStream.prototype.insertAhead = function(/**JSDOC.Token*/token) {

	this.tokens.splice(this.cursor+1, 0, token);

}