/trunk/jsdoc-toolkit/app/lib/JSDOC/TokenStream.js

  1if (typeof JSDOC == "undefined") JSDOC = {};
  2
  3/**
  4	@constructor
  5*/
  6JSDOC.TokenStream = function(tokens) {
  7	this.tokens = (tokens || []);
  8	this.rewind();
  9}
 10
 11/**
 12	@constructor
 13	@private
 14*/
 15function VoidToken(/**String*/type) {
 16	this.toString = function() {return "<VOID type=\""+type+"\">"};
 17	this.is = function(){return false;}
 18}
 19
 20JSDOC.TokenStream.prototype.rewind = function() {
 21	this.cursor = -1;
 22}
 23
 24/**
 25	@type JSDOC.Token
 26*/
 27JSDOC.TokenStream.prototype.look = function(/**Number*/n, /**Boolean*/considerWhitespace) {
 28	if (typeof n == "undefined") n = 0;
 29
 30	if (considerWhitespace == true) {
 31		if (this.cursor+n < 0 || this.cursor+n > this.tokens.length) return {};
 32		return this.tokens[this.cursor+n];
 33	}
 34	else {
 35		var count = 0;
 36		var i = this.cursor;
 37
 38		while (true) {
 39			if (i < 0) return new JSDOC.Token("", "VOID", "START_OF_STREAM");
 40			else if (i > this.tokens.length) return new JSDOC.Token("", "VOID", "END_OF_STREAM");
 41
 42			if (i != this.cursor && (this.tokens[i] === undefined || this.tokens[i].is("WHIT"))) {
 43				if (n < 0) i--; else i++;
 44				continue;
 45			}
 46			
 47			if (count == Math.abs(n)) {
 48				return this.tokens[i];
 49			}
 50			count++;
 51			(n < 0)? i-- : i++;
 52		}
 53
 54		return new JSDOC.Token("", "VOID", "STREAM_ERROR"); // because null isn't an object and caller always expects an object
 55	}
 56}
 57
 58/**
 59	@type JSDOC.Token|JSDOC.Token[]
 60*/
 61JSDOC.TokenStream.prototype.next = function(/**Number*/howMany) {
 62	if (typeof howMany == "undefined") howMany = 1;
 63	if (howMany < 1) return null;
 64	var got = [];
 65
 66	for (var i = 1; i <= howMany; i++) {
 67		if (this.cursor+i >= this.tokens.length) {
 68			return null;
 69		}
 70		got.push(this.tokens[this.cursor+i]);
 71	}
 72	this.cursor += howMany;
 73
 74	if (howMany == 1) {
 75		return got[0];
 76	}
 77	else return got;
 78}
 79
 80/**
 81	@type JSDOC.Token[]
 82*/
 83JSDOC.TokenStream.prototype.balance = function(/**String*/start, /**String*/stop) {
 84	if (!stop) stop = JSDOC.Lang.matching(start);
 85	
 86	var depth = 0;
 87	var got = [];
 88	var started = false;
 89	
 90	while ((token = this.look())) {
 91		if (token.is(start)) {
 92			depth++;
 93			started = true;
 94		}
 95		
 96		if (started) {
 97			got.push(token);
 98		}
 99		
100		if (token.is(stop)) {
101			depth--;
102			if (depth == 0) return got;
103		}
104		if (!this.next()) break;
105	}
106}
107
108JSDOC.TokenStream.prototype.getMatchingToken = function(/**String*/start, /**String*/stop) {
109	var depth = 0;
110	var cursor = this.cursor;
111	
112	if (!start) {
113		start = JSDOC.Lang.matching(stop);
114		depth = 1;
115	}
116	if (!stop) stop = JSDOC.Lang.matching(start);
117	
118	while ((token = this.tokens[cursor])) {
119		if (token.is(start)) {
120			depth++;
121		}
122		
123		if (token.is(stop) && cursor) {
124			depth--;
125			if (depth == 0) return this.tokens[cursor];
126		}
127		cursor++;
128	}
129}
130
131JSDOC.TokenStream.prototype.insertAhead = function(/**JSDOC.Token*/token) {
132	this.tokens.splice(this.cursor+1, 0, token);
133}
134
135JSDOC.TokenStream.tokensToString = function(tokens) {
136	var str = [];
137	for (var i = 0, leni = tokens.length; i < leni; i++) {
138		str.push(tokens[i].data);
139	}
140	return str.join('');
141}