michael@0: /***
michael@0: 
michael@0: MochiKit.Iter 1.4.2
michael@0: 
michael@0: See <http://mochikit.com/> for documentation, downloads, license, etc.
michael@0: 
michael@0: (c) 2005 Bob Ippolito.  All rights Reserved.
michael@0: 
michael@0: ***/
michael@0: 
michael@0: MochiKit.Base._deps('Iter', ['Base']);
michael@0: 
michael@0: MochiKit.Iter.NAME = "MochiKit.Iter";
michael@0: MochiKit.Iter.VERSION = "1.4.2";
michael@0: MochiKit.Base.update(MochiKit.Iter, {
michael@0:     __repr__: function () {
michael@0:         return "[" + this.NAME + " " + this.VERSION + "]";
michael@0:     },
michael@0:     toString: function () {
michael@0:         return this.__repr__();
michael@0:     },
michael@0: 
michael@0:     /** @id MochiKit.Iter.registerIteratorFactory */
michael@0:     registerIteratorFactory: function (name, check, iterfactory, /* optional */ override) {
michael@0:         MochiKit.Iter.iteratorRegistry.register(name, check, iterfactory, override);
michael@0:     },
michael@0: 
michael@0:     /** @id MochiKit.Iter.isIterable */
michael@0:     isIterable: function(o) {
michael@0:         return o != null &&
michael@0:                (typeof(o.next) == "function" || typeof(o.iter) == "function");
michael@0:     },
michael@0: 
michael@0:     /** @id MochiKit.Iter.iter */
michael@0:     iter: function (iterable, /* optional */ sentinel) {
michael@0:         var self = MochiKit.Iter;
michael@0:         if (arguments.length == 2) {
michael@0:             return self.takewhile(
michael@0:                 function (a) { return a != sentinel; },
michael@0:                 iterable
michael@0:             );
michael@0:         }
michael@0:         if (typeof(iterable.next) == 'function') {
michael@0:             return iterable;
michael@0:         } else if (typeof(iterable.iter) == 'function') {
michael@0:             return iterable.iter();
michael@0:         /*
michael@0:         }  else if (typeof(iterable.__iterator__) == 'function') {
michael@0:             //
michael@0:             // XXX: We can't support JavaScript 1.7 __iterator__ directly
michael@0:             //      because of Object.prototype.__iterator__
michael@0:             //
michael@0:             return iterable.__iterator__();
michael@0:         */
michael@0:         }
michael@0: 
michael@0:         try {
michael@0:             return self.iteratorRegistry.match(iterable);
michael@0:         } catch (e) {
michael@0:             var m = MochiKit.Base;
michael@0:             if (e == m.NotFound) {
michael@0:                 e = new TypeError(typeof(iterable) + ": " + m.repr(iterable) + " is not iterable");
michael@0:             }
michael@0:             throw e;
michael@0:         }
michael@0:     },
michael@0: 
michael@0:     /** @id MochiKit.Iter.count */
michael@0:     count: function (n) {
michael@0:         if (!n) {
michael@0:             n = 0;
michael@0:         }
michael@0:         var m = MochiKit.Base;
michael@0:         return {
michael@0:             repr: function () { return "count(" + n + ")"; },
michael@0:             toString: m.forwardCall("repr"),
michael@0:             next: m.counter(n)
michael@0:         };
michael@0:     },
michael@0: 
michael@0:     /** @id MochiKit.Iter.cycle */
michael@0:     cycle: function (p) {
michael@0:         var self = MochiKit.Iter;
michael@0:         var m = MochiKit.Base;
michael@0:         var lst = [];
michael@0:         var iterator = self.iter(p);
michael@0:         return {
michael@0:             repr: function () { return "cycle(...)"; },
michael@0:             toString: m.forwardCall("repr"),
michael@0:             next: function () {
michael@0:                 try {
michael@0:                     var rval = iterator.next();
michael@0:                     lst.push(rval);
michael@0:                     return rval;
michael@0:                 } catch (e) {
michael@0:                     if (e != self.StopIteration) {
michael@0:                         throw e;
michael@0:                     }
michael@0:                     if (lst.length === 0) {
michael@0:                         this.next = function () {
michael@0:                             throw self.StopIteration;
michael@0:                         };
michael@0:                     } else {
michael@0:                         var i = -1;
michael@0:                         this.next = function () {
michael@0:                             i = (i + 1) % lst.length;
michael@0:                             return lst[i];
michael@0:                         };
michael@0:                     }
michael@0:                     return this.next();
michael@0:                 }
michael@0:             }
michael@0:         };
michael@0:     },
michael@0: 
michael@0:     /** @id MochiKit.Iter.repeat */
michael@0:     repeat: function (elem, /* optional */n) {
michael@0:         var m = MochiKit.Base;
michael@0:         if (typeof(n) == 'undefined') {
michael@0:             return {
michael@0:                 repr: function () {
michael@0:                     return "repeat(" + m.repr(elem) + ")";
michael@0:                 },
michael@0:                 toString: m.forwardCall("repr"),
michael@0:                 next: function () {
michael@0:                     return elem;
michael@0:                 }
michael@0:             };
michael@0:         }
michael@0:         return {
michael@0:             repr: function () {
michael@0:                 return "repeat(" + m.repr(elem) + ", " + n + ")";
michael@0:             },
michael@0:             toString: m.forwardCall("repr"),
michael@0:             next: function () {
michael@0:                 if (n <= 0) {
michael@0:                     throw MochiKit.Iter.StopIteration;
michael@0:                 }
michael@0:                 n -= 1;
michael@0:                 return elem;
michael@0:             }
michael@0:         };
michael@0:     },
michael@0: 
michael@0:     /** @id MochiKit.Iter.next */
michael@0:     next: function (iterator) {
michael@0:         return iterator.next();
michael@0:     },
michael@0: 
michael@0:     /** @id MochiKit.Iter.izip */
michael@0:     izip: function (p, q/*, ...*/) {
michael@0:         var m = MochiKit.Base;
michael@0:         var self = MochiKit.Iter;
michael@0:         var next = self.next;
michael@0:         var iterables = m.map(self.iter, arguments);
michael@0:         return {
michael@0:             repr: function () { return "izip(...)"; },
michael@0:             toString: m.forwardCall("repr"),
michael@0:             next: function () { return m.map(next, iterables); }
michael@0:         };
michael@0:     },
michael@0: 
michael@0:     /** @id MochiKit.Iter.ifilter */
michael@0:     ifilter: function (pred, seq) {
michael@0:         var m = MochiKit.Base;
michael@0:         seq = MochiKit.Iter.iter(seq);
michael@0:         if (pred === null) {
michael@0:             pred = m.operator.truth;
michael@0:         }
michael@0:         return {
michael@0:             repr: function () { return "ifilter(...)"; },
michael@0:             toString: m.forwardCall("repr"),
michael@0:             next: function () {
michael@0:                 while (true) {
michael@0:                     var rval = seq.next();
michael@0:                     if (pred(rval)) {
michael@0:                         return rval;
michael@0:                     }
michael@0:                 }
michael@0:                 // mozilla warnings aren't too bright
michael@0:                 return undefined;
michael@0:             }
michael@0:         };
michael@0:     },
michael@0: 
michael@0:     /** @id MochiKit.Iter.ifilterfalse */
michael@0:     ifilterfalse: function (pred, seq) {
michael@0:         var m = MochiKit.Base;
michael@0:         seq = MochiKit.Iter.iter(seq);
michael@0:         if (pred === null) {
michael@0:             pred = m.operator.truth;
michael@0:         }
michael@0:         return {
michael@0:             repr: function () { return "ifilterfalse(...)"; },
michael@0:             toString: m.forwardCall("repr"),
michael@0:             next: function () {
michael@0:                 while (true) {
michael@0:                     var rval = seq.next();
michael@0:                     if (!pred(rval)) {
michael@0:                         return rval;
michael@0:                     }
michael@0:                 }
michael@0:                 // mozilla warnings aren't too bright
michael@0:                 return undefined;
michael@0:             }
michael@0:         };
michael@0:     },
michael@0: 
michael@0:     /** @id MochiKit.Iter.islice */
michael@0:     islice: function (seq/*, [start,] stop[, step] */) {
michael@0:         var self = MochiKit.Iter;
michael@0:         var m = MochiKit.Base;
michael@0:         seq = self.iter(seq);
michael@0:         var start = 0;
michael@0:         var stop = 0;
michael@0:         var step = 1;
michael@0:         var i = -1;
michael@0:         if (arguments.length == 2) {
michael@0:             stop = arguments[1];
michael@0:         } else if (arguments.length == 3) {
michael@0:             start = arguments[1];
michael@0:             stop = arguments[2];
michael@0:         } else {
michael@0:             start = arguments[1];
michael@0:             stop = arguments[2];
michael@0:             step = arguments[3];
michael@0:         }
michael@0:         return {
michael@0:             repr: function () {
michael@0:                 return "islice(" + ["...", start, stop, step].join(", ") + ")";
michael@0:             },
michael@0:             toString: m.forwardCall("repr"),
michael@0:             next: function () {
michael@0:                 var rval;
michael@0:                 while (i < start) {
michael@0:                     rval = seq.next();
michael@0:                     i++;
michael@0:                 }
michael@0:                 if (start >= stop) {
michael@0:                     throw self.StopIteration;
michael@0:                 }
michael@0:                 start += step;
michael@0:                 return rval;
michael@0:             }
michael@0:         };
michael@0:     },
michael@0: 
michael@0:     /** @id MochiKit.Iter.imap */
michael@0:     imap: function (fun, p, q/*, ...*/) {
michael@0:         var m = MochiKit.Base;
michael@0:         var self = MochiKit.Iter;
michael@0:         var iterables = m.map(self.iter, m.extend(null, arguments, 1));
michael@0:         var map = m.map;
michael@0:         var next = self.next;
michael@0:         return {
michael@0:             repr: function () { return "imap(...)"; },
michael@0:             toString: m.forwardCall("repr"),
michael@0:             next: function () {
michael@0:                 return fun.apply(this, map(next, iterables));
michael@0:             }
michael@0:         };
michael@0:     },
michael@0: 
michael@0:     /** @id MochiKit.Iter.applymap */
michael@0:     applymap: function (fun, seq, self) {
michael@0:         seq = MochiKit.Iter.iter(seq);
michael@0:         var m = MochiKit.Base;
michael@0:         return {
michael@0:             repr: function () { return "applymap(...)"; },
michael@0:             toString: m.forwardCall("repr"),
michael@0:             next: function () {
michael@0:                 return fun.apply(self, seq.next());
michael@0:             }
michael@0:         };
michael@0:     },
michael@0: 
michael@0:     /** @id MochiKit.Iter.chain */
michael@0:     chain: function (p, q/*, ...*/) {
michael@0:         // dumb fast path
michael@0:         var self = MochiKit.Iter;
michael@0:         var m = MochiKit.Base;
michael@0:         if (arguments.length == 1) {
michael@0:             return self.iter(arguments[0]);
michael@0:         }
michael@0:         var argiter = m.map(self.iter, arguments);
michael@0:         return {
michael@0:             repr: function () { return "chain(...)"; },
michael@0:             toString: m.forwardCall("repr"),
michael@0:             next: function () {
michael@0:                 while (argiter.length > 1) {
michael@0:                     try {
michael@0:                         var result = argiter[0].next();
michael@0:                         return result;
michael@0:                     } catch (e) {
michael@0:                         if (e != self.StopIteration) {
michael@0:                             throw e;
michael@0:                         }
michael@0:                         argiter.shift();
michael@0:                         var result = argiter[0].next();
michael@0:                         return result;
michael@0:                     }
michael@0:                 }
michael@0:                 if (argiter.length == 1) {
michael@0:                     // optimize last element
michael@0:                     var arg = argiter.shift();
michael@0:                     this.next = m.bind("next", arg);
michael@0:                     return this.next();
michael@0:                 }
michael@0:                 throw self.StopIteration;
michael@0:             }
michael@0:         };
michael@0:     },
michael@0: 
michael@0:     /** @id MochiKit.Iter.takewhile */
michael@0:     takewhile: function (pred, seq) {
michael@0:         var self = MochiKit.Iter;
michael@0:         seq = self.iter(seq);
michael@0:         return {
michael@0:             repr: function () { return "takewhile(...)"; },
michael@0:             toString: MochiKit.Base.forwardCall("repr"),
michael@0:             next: function () {
michael@0:                 var rval = seq.next();
michael@0:                 if (!pred(rval)) {
michael@0:                     this.next = function () {
michael@0:                         throw self.StopIteration;
michael@0:                     };
michael@0:                     this.next();
michael@0:                 }
michael@0:                 return rval;
michael@0:             }
michael@0:         };
michael@0:     },
michael@0: 
michael@0:     /** @id MochiKit.Iter.dropwhile */
michael@0:     dropwhile: function (pred, seq) {
michael@0:         seq = MochiKit.Iter.iter(seq);
michael@0:         var m = MochiKit.Base;
michael@0:         var bind = m.bind;
michael@0:         return {
michael@0:             "repr": function () { return "dropwhile(...)"; },
michael@0:             "toString": m.forwardCall("repr"),
michael@0:             "next": function () {
michael@0:                 while (true) {
michael@0:                     var rval = seq.next();
michael@0:                     if (!pred(rval)) {
michael@0:                         break;
michael@0:                     }
michael@0:                 }
michael@0:                 this.next = bind("next", seq);
michael@0:                 return rval;
michael@0:             }
michael@0:         };
michael@0:     },
michael@0: 
michael@0:     _tee: function (ident, sync, iterable) {
michael@0:         sync.pos[ident] = -1;
michael@0:         var m = MochiKit.Base;
michael@0:         var listMin = m.listMin;
michael@0:         return {
michael@0:             repr: function () { return "tee(" + ident + ", ...)"; },
michael@0:             toString: m.forwardCall("repr"),
michael@0:             next: function () {
michael@0:                 var rval;
michael@0:                 var i = sync.pos[ident];
michael@0: 
michael@0:                 if (i == sync.max) {
michael@0:                     rval = iterable.next();
michael@0:                     sync.deque.push(rval);
michael@0:                     sync.max += 1;
michael@0:                     sync.pos[ident] += 1;
michael@0:                 } else {
michael@0:                     rval = sync.deque[i - sync.min];
michael@0:                     sync.pos[ident] += 1;
michael@0:                     if (i == sync.min && listMin(sync.pos) != sync.min) {
michael@0:                         sync.min += 1;
michael@0:                         sync.deque.shift();
michael@0:                     }
michael@0:                 }
michael@0:                 return rval;
michael@0:             }
michael@0:         };
michael@0:     },
michael@0: 
michael@0:     /** @id MochiKit.Iter.tee */
michael@0:     tee: function (iterable, n/* = 2 */) {
michael@0:         var rval = [];
michael@0:         var sync = {
michael@0:             "pos": [],
michael@0:             "deque": [],
michael@0:             "max": -1,
michael@0:             "min": -1
michael@0:         };
michael@0:         if (arguments.length == 1 || typeof(n) == "undefined" || n === null) {
michael@0:             n = 2;
michael@0:         }
michael@0:         var self = MochiKit.Iter;
michael@0:         iterable = self.iter(iterable);
michael@0:         var _tee = self._tee;
michael@0:         for (var i = 0; i < n; i++) {
michael@0:             rval.push(_tee(i, sync, iterable));
michael@0:         }
michael@0:         return rval;
michael@0:     },
michael@0: 
michael@0:     /** @id MochiKit.Iter.list */
michael@0:     list: function (iterable) {
michael@0:         // Fast-path for Array and Array-like
michael@0:         var rval;
michael@0:         if (iterable instanceof Array) {
michael@0:             return iterable.slice();
michael@0:         } 
michael@0:         // this is necessary to avoid a Safari crash
michael@0:         if (typeof(iterable) == "function" &&
michael@0:                 !(iterable instanceof Function) &&
michael@0:                 typeof(iterable.length) == 'number') {
michael@0:             rval = [];
michael@0:             for (var i = 0; i < iterable.length; i++) {
michael@0:                 rval.push(iterable[i]);
michael@0:             }
michael@0:             return rval;
michael@0:         }
michael@0: 
michael@0:         var self = MochiKit.Iter;
michael@0:         iterable = self.iter(iterable);
michael@0:         var rval = [];
michael@0:         var a_val;
michael@0:         try {
michael@0:             while (true) {
michael@0:                 a_val = iterable.next();
michael@0:                 rval.push(a_val);
michael@0:             }
michael@0:         } catch (e) {
michael@0:             if (e != self.StopIteration) {
michael@0:                 throw e;
michael@0:             }
michael@0:             return rval;
michael@0:         }
michael@0:         // mozilla warnings aren't too bright
michael@0:         return undefined;
michael@0:     },
michael@0: 
michael@0: 
michael@0:     /** @id MochiKit.Iter.reduce */
michael@0:     reduce: function (fn, iterable, /* optional */initial) {
michael@0:         var i = 0;
michael@0:         var x = initial;
michael@0:         var self = MochiKit.Iter;
michael@0:         iterable = self.iter(iterable);
michael@0:         if (arguments.length < 3) {
michael@0:             try {
michael@0:                 x = iterable.next();
michael@0:             } catch (e) {
michael@0:                 if (e == self.StopIteration) {
michael@0:                     e = new TypeError("reduce() of empty sequence with no initial value");
michael@0:                 }
michael@0:                 throw e;
michael@0:             }
michael@0:             i++;
michael@0:         }
michael@0:         try {
michael@0:             while (true) {
michael@0:                 x = fn(x, iterable.next());
michael@0:             }
michael@0:         } catch (e) {
michael@0:             if (e != self.StopIteration) {
michael@0:                 throw e;
michael@0:             }
michael@0:         }
michael@0:         return x;
michael@0:     },
michael@0: 
michael@0:     /** @id MochiKit.Iter.range */
michael@0:     range: function (/* [start,] stop[, step] */) {
michael@0:         var start = 0;
michael@0:         var stop = 0;
michael@0:         var step = 1;
michael@0:         if (arguments.length == 1) {
michael@0:             stop = arguments[0];
michael@0:         } else if (arguments.length == 2) {
michael@0:             start = arguments[0];
michael@0:             stop = arguments[1];
michael@0:         } else if (arguments.length == 3) {
michael@0:             start = arguments[0];
michael@0:             stop = arguments[1];
michael@0:             step = arguments[2];
michael@0:         } else {
michael@0:             throw new TypeError("range() takes 1, 2, or 3 arguments!");
michael@0:         }
michael@0:         if (step === 0) {
michael@0:             throw new TypeError("range() step must not be 0");
michael@0:         }
michael@0:         return {
michael@0:             next: function () {
michael@0:                 if ((step > 0 && start >= stop) || (step < 0 && start <= stop)) {
michael@0:                     throw MochiKit.Iter.StopIteration;
michael@0:                 }
michael@0:                 var rval = start;
michael@0:                 start += step;
michael@0:                 return rval;
michael@0:             },
michael@0:             repr: function () {
michael@0:                 return "range(" + [start, stop, step].join(", ") + ")";
michael@0:             },
michael@0:             toString: MochiKit.Base.forwardCall("repr")
michael@0:         };
michael@0:     },
michael@0: 
michael@0:     /** @id MochiKit.Iter.sum */
michael@0:     sum: function (iterable, start/* = 0 */) {
michael@0:         if (typeof(start) == "undefined" || start === null) {
michael@0:             start = 0;
michael@0:         }
michael@0:         var x = start;
michael@0:         var self = MochiKit.Iter;
michael@0:         iterable = self.iter(iterable);
michael@0:         try {
michael@0:             while (true) {
michael@0:                 x += iterable.next();
michael@0:             }
michael@0:         } catch (e) {
michael@0:             if (e != self.StopIteration) {
michael@0:                 throw e;
michael@0:             }
michael@0:         }
michael@0:         return x;
michael@0:     },
michael@0: 
michael@0:     /** @id MochiKit.Iter.exhaust */
michael@0:     exhaust: function (iterable) {
michael@0:         var self = MochiKit.Iter;
michael@0:         iterable = self.iter(iterable);
michael@0:         try {
michael@0:             while (true) {
michael@0:                 iterable.next();
michael@0:             }
michael@0:         } catch (e) {
michael@0:             if (e != self.StopIteration) {
michael@0:                 throw e;
michael@0:             }
michael@0:         }
michael@0:     },
michael@0: 
michael@0:     /** @id MochiKit.Iter.forEach */
michael@0:     forEach: function (iterable, func, /* optional */obj) {
michael@0:         var m = MochiKit.Base;
michael@0:         var self = MochiKit.Iter;
michael@0:         if (arguments.length > 2) {
michael@0:             func = m.bind(func, obj);
michael@0:         }
michael@0:         // fast path for array
michael@0:         if (m.isArrayLike(iterable) && !self.isIterable(iterable)) {
michael@0:             try {
michael@0:                 for (var i = 0; i < iterable.length; i++) {
michael@0:                     func(iterable[i]);
michael@0:                 }
michael@0:             } catch (e) {
michael@0:                 if (e != self.StopIteration) {
michael@0:                     throw e;
michael@0:                 }
michael@0:             }
michael@0:         } else {
michael@0:             self.exhaust(self.imap(func, iterable));
michael@0:         }
michael@0:     },
michael@0: 
michael@0:     /** @id MochiKit.Iter.every */
michael@0:     every: function (iterable, func) {
michael@0:         var self = MochiKit.Iter;
michael@0:         try {
michael@0:             self.ifilterfalse(func, iterable).next();
michael@0:             return false;
michael@0:         } catch (e) {
michael@0:             if (e != self.StopIteration) {
michael@0:                 throw e;
michael@0:             }
michael@0:             return true;
michael@0:         }
michael@0:     },
michael@0: 
michael@0:     /** @id MochiKit.Iter.sorted */
michael@0:     sorted: function (iterable, /* optional */cmp) {
michael@0:         var rval = MochiKit.Iter.list(iterable);
michael@0:         if (arguments.length == 1) {
michael@0:             cmp = MochiKit.Base.compare;
michael@0:         }
michael@0:         rval.sort(cmp);
michael@0:         return rval;
michael@0:     },
michael@0: 
michael@0:     /** @id MochiKit.Iter.reversed */
michael@0:     reversed: function (iterable) {
michael@0:         var rval = MochiKit.Iter.list(iterable);
michael@0:         rval.reverse();
michael@0:         return rval;
michael@0:     },
michael@0: 
michael@0:     /** @id MochiKit.Iter.some */
michael@0:     some: function (iterable, func) {
michael@0:         var self = MochiKit.Iter;
michael@0:         try {
michael@0:             self.ifilter(func, iterable).next();
michael@0:             return true;
michael@0:         } catch (e) {
michael@0:             if (e != self.StopIteration) {
michael@0:                 throw e;
michael@0:             }
michael@0:             return false;
michael@0:         }
michael@0:     },
michael@0: 
michael@0:     /** @id MochiKit.Iter.iextend */
michael@0:     iextend: function (lst, iterable) {
michael@0:         var m = MochiKit.Base;
michael@0:         var self = MochiKit.Iter;
michael@0:         if (m.isArrayLike(iterable) && !self.isIterable(iterable)) {
michael@0:             // fast-path for array-like
michael@0:             for (var i = 0; i < iterable.length; i++) {
michael@0:                 lst.push(iterable[i]);
michael@0:             }
michael@0:         } else {
michael@0:             iterable = self.iter(iterable);
michael@0:             try {
michael@0:                 while (true) {
michael@0:                     lst.push(iterable.next());
michael@0:                 }
michael@0:             } catch (e) {
michael@0:                 if (e != self.StopIteration) {
michael@0:                     throw e;
michael@0:                 }
michael@0:             }
michael@0:         }
michael@0:         return lst;
michael@0:     },
michael@0: 
michael@0:     /** @id MochiKit.Iter.groupby */
michael@0:     groupby: function(iterable, /* optional */ keyfunc) {
michael@0:         var m = MochiKit.Base;
michael@0:         var self = MochiKit.Iter;
michael@0:         if (arguments.length < 2) {
michael@0:             keyfunc = m.operator.identity;
michael@0:         }
michael@0:         iterable = self.iter(iterable);
michael@0: 
michael@0:         // shared
michael@0:         var pk = undefined;
michael@0:         var k = undefined;
michael@0:         var v;
michael@0: 
michael@0:         function fetch() {
michael@0:             v = iterable.next();
michael@0:             k = keyfunc(v);
michael@0:         };
michael@0: 
michael@0:         function eat() {
michael@0:             var ret = v;
michael@0:             v = undefined;
michael@0:             return ret;
michael@0:         };
michael@0: 
michael@0:         var first = true;
michael@0:         var compare = m.compare;
michael@0:         return {
michael@0:             repr: function () { return "groupby(...)"; },
michael@0:             next: function() {
michael@0:                 // iterator-next
michael@0: 
michael@0:                 // iterate until meet next group
michael@0:                 while (compare(k, pk) === 0) {
michael@0:                     fetch();
michael@0:                     if (first) {
michael@0:                         first = false;
michael@0:                         break;
michael@0:                     }
michael@0:                 }
michael@0:                 pk = k;
michael@0:                 return [k, {
michael@0:                     next: function() {
michael@0:                         // subiterator-next
michael@0:                         if (v == undefined) { // Is there something to eat?
michael@0:                             fetch();
michael@0:                         }
michael@0:                         if (compare(k, pk) !== 0) {
michael@0:                             throw self.StopIteration;
michael@0:                         }
michael@0:                         return eat();
michael@0:                     }
michael@0:                 }];
michael@0:             }
michael@0:         };
michael@0:     },
michael@0: 
michael@0:     /** @id MochiKit.Iter.groupby_as_array */
michael@0:     groupby_as_array: function (iterable, /* optional */ keyfunc) {
michael@0:         var m = MochiKit.Base;
michael@0:         var self = MochiKit.Iter;
michael@0:         if (arguments.length < 2) {
michael@0:             keyfunc = m.operator.identity;
michael@0:         }
michael@0: 
michael@0:         iterable = self.iter(iterable);
michael@0:         var result = [];
michael@0:         var first = true;
michael@0:         var prev_key;
michael@0:         var compare = m.compare;
michael@0:         while (true) {
michael@0:             try {
michael@0:                 var value = iterable.next();
michael@0:                 var key = keyfunc(value);
michael@0:             } catch (e) {
michael@0:                 if (e == self.StopIteration) {
michael@0:                     break;
michael@0:                 }
michael@0:                 throw e;
michael@0:             }
michael@0:             if (first || compare(key, prev_key) !== 0) {
michael@0:                 var values = [];
michael@0:                 result.push([key, values]);
michael@0:             }
michael@0:             values.push(value);
michael@0:             first = false;
michael@0:             prev_key = key;
michael@0:         }
michael@0:         return result;
michael@0:     },
michael@0: 
michael@0:     /** @id MochiKit.Iter.arrayLikeIter */
michael@0:     arrayLikeIter: function (iterable) {
michael@0:         var i = 0;
michael@0:         return {
michael@0:             repr: function () { return "arrayLikeIter(...)"; },
michael@0:             toString: MochiKit.Base.forwardCall("repr"),
michael@0:             next: function () {
michael@0:                 if (i >= iterable.length) {
michael@0:                     throw MochiKit.Iter.StopIteration;
michael@0:                 }
michael@0:                 return iterable[i++];
michael@0:             }
michael@0:         };
michael@0:     },
michael@0: 
michael@0:     /** @id MochiKit.Iter.hasIterateNext */
michael@0:     hasIterateNext: function (iterable) {
michael@0:         return (iterable && typeof(iterable.iterateNext) == "function");
michael@0:     },
michael@0: 
michael@0:     /** @id MochiKit.Iter.iterateNextIter */
michael@0:     iterateNextIter: function (iterable) {
michael@0:         return {
michael@0:             repr: function () { return "iterateNextIter(...)"; },
michael@0:             toString: MochiKit.Base.forwardCall("repr"),
michael@0:             next: function () {
michael@0:                 var rval = iterable.iterateNext();
michael@0:                 if (rval === null || rval === undefined) {
michael@0:                     throw MochiKit.Iter.StopIteration;
michael@0:                 }
michael@0:                 return rval;
michael@0:             }
michael@0:         };
michael@0:     }
michael@0: });
michael@0: 
michael@0: 
michael@0: MochiKit.Iter.EXPORT_OK = [
michael@0:     "iteratorRegistry",
michael@0:     "arrayLikeIter",
michael@0:     "hasIterateNext",
michael@0:     "iterateNextIter"
michael@0: ];
michael@0: 
michael@0: MochiKit.Iter.EXPORT = [
michael@0:     "StopIteration",
michael@0:     "registerIteratorFactory",
michael@0:     "iter",
michael@0:     "count",
michael@0:     "cycle",
michael@0:     "repeat",
michael@0:     "next",
michael@0:     "izip",
michael@0:     "ifilter",
michael@0:     "ifilterfalse",
michael@0:     "islice",
michael@0:     "imap",
michael@0:     "applymap",
michael@0:     "chain",
michael@0:     "takewhile",
michael@0:     "dropwhile",
michael@0:     "tee",
michael@0:     "list",
michael@0:     "reduce",
michael@0:     "range",
michael@0:     "sum",
michael@0:     "exhaust",
michael@0:     "forEach",
michael@0:     "every",
michael@0:     "sorted",
michael@0:     "reversed",
michael@0:     "some",
michael@0:     "iextend",
michael@0:     "groupby",
michael@0:     "groupby_as_array"
michael@0: ];
michael@0: 
michael@0: MochiKit.Iter.__new__ = function () {
michael@0:     var m = MochiKit.Base;
michael@0:     // Re-use StopIteration if exists (e.g. SpiderMonkey)
michael@0:     if (typeof(StopIteration) != "undefined") {
michael@0:         this.StopIteration = StopIteration;
michael@0:     } else {
michael@0:         /** @id MochiKit.Iter.StopIteration */
michael@0:         this.StopIteration = new m.NamedError("StopIteration");
michael@0:     }
michael@0:     this.iteratorRegistry = new m.AdapterRegistry();
michael@0:     // Register the iterator factory for arrays
michael@0:     this.registerIteratorFactory(
michael@0:         "arrayLike",
michael@0:         m.isArrayLike,
michael@0:         this.arrayLikeIter
michael@0:     );
michael@0: 
michael@0:     this.registerIteratorFactory(
michael@0:         "iterateNext",
michael@0:         this.hasIterateNext,
michael@0:         this.iterateNextIter
michael@0:     );
michael@0: 
michael@0:     this.EXPORT_TAGS = {
michael@0:         ":common": this.EXPORT,
michael@0:         ":all": m.concat(this.EXPORT, this.EXPORT_OK)
michael@0:     };
michael@0: 
michael@0:     m.nameFunctions(this);
michael@0: 
michael@0: };
michael@0: 
michael@0: MochiKit.Iter.__new__();
michael@0: 
michael@0: //
michael@0: // XXX: Internet Explorer blows
michael@0: //
michael@0: if (MochiKit.__export__) {
michael@0:     reduce = MochiKit.Iter.reduce;
michael@0: }
michael@0: 
michael@0: MochiKit.Base._exportSymbols(this, MochiKit.Iter);