159         result += source.slice(0, match.index);
161         source  = source.slice(match.index + match[0].length);
324     var index = 0;
328           iterator(value, index++);
340     var index = -number, slices = [], array = this.toArray();
341     while ((index += number) < array.length)
342       slices.push(array.slice(index, index+number));
348     this.each(function(value, index) {  argument
349       result = result && !!(iterator || Prototype.K)(value, index);
357     this.each(function(value, index) {  argument
358       if (result = !!(iterator || Prototype.K)(value, index))
366     this.each(function(value, index) {  argument
367       results.push((iterator || Prototype.K)(value, index));
374     this.each(function(value, index) {  argument
375       if (iterator(value, index)) {
385     this.each(function(value, index) {  argument
386       if (iterator(value, index))
394     this.each(function(value, index) {  argument
397         results.push((iterator || Prototype.K)(value, index));
422     this.each(function(value, index) {  argument
423       memo = iterator(memo, value, index);
437     this.each(function(value, index) {  argument
438       value = (iterator || Prototype.K)(value, index);
447     this.each(function(value, index) {  argument
448       value = (iterator || Prototype.K)(value, index);
457     this.each(function(value, index) {  argument
458       ((iterator || Prototype.K)(value, index) ?
466     this.each(function(value, index) {  argument
474     this.each(function(value, index) {  argument
475       if (!iterator(value, index))
482     return this.map(function(value, index) {  argument
483       return {value: value, criteria: iterator(value, index)};
500     return this.map(function(value, index) {  argument
501       return iterator(collections.pluck(index));
1244   up: function(element, expression, index) {  argument
1245     return Selector.findElement($(element).ancestors(), expression, index);
1248   down: function(element, expression, index) {  argument
1249     return Selector.findElement($(element).descendants(), expression, index);
1252   previous: function(element, expression, index) {  argument
1253     return Selector.findElement($(element).previousSiblings(), expression, index);
1256   next: function(element, expression, index) {  argument
1257     return Selector.findElement($(element).nextSiblings(), expression, index);
1853   findElement: function(elements, expression, index) {  argument
1854     if (typeof expression == 'number') index = expression, expression = false;
1855     return Selector.matchElements(elements, expression || '*')[index || 0];
2059     var index = element.selectedIndex;
2060     return index >= 0 ? this.optionValue(element.options[index]) : null;