The document discusses FuseJS, a JavaScript framework that aims to improve performance and compatibility across browsers. It includes sandboxed native objects to prevent namespace pollution, modular builds, and various selector engines. It also details optimizations for quirks mode, events, caching, and performance benchmarks showing FuseJS has lower execution times than other frameworks.

1. All You Can Leet A heaping helping of performance , selector engines, & sandbox natives By John-David Dalton @jdalton ▪ john@fusejs.com ▪ http://allyoucanleet.com

2. function times(iterator, context) { $R( 0, this, true ) . each( iterator, context ) ; return this; } Performance Reduce Abstraction

3. Performance function times(iterator, context) { var i = -1, length = this; while ( ++i < length ) iterator.call(context, i, i); return length; } Reduce Abstraction

4. Performance function contains(element, descendant) { if (element. compareDocumentPosition ) { return (descendant .compareDocumentPosition(element) & 8) === 8; } if (element. contains ) { return element !== descendant && element.contains(element); } while ( descendant = descendant.parentNode ) { if (descendant == element) return true; } return false; } Fork like Rabbits

5. function isHostObject(object, property) { var type = typeof object[property]; return type === ' object ' ? !!object[property] : !/^( boolean | number | string | undefined )$/.test(type); } var contains = function(element, descendant) { while ( descendant = descendant.parentNode ) if (descendant === element) return true; } return false; }; if ( isHostObject(docEl, 'compareDocumentPosition') ) { contains = function(element, descendant) { /* DOCUMENT_POSITION_CONTAINS = 0x08 */ return (descendant .compareDocumentPosition(element) & 8) === 8; }; } else if ( isHostObject(docEl, 'contains') ) { contains = function(element, descendant) { return element !== descendant && element.contains(descendant); } Performance Fork like Rabbits

6. var type = typeof object[property]; return type === ' object ' ? !!object[property] : !/^( boolean | number | string | undefined )$/.test(type); } var contains = function(element, descendant) { while ( descendant = descendant.parentNode ) { if (descendant === element) return true; } re tur n false; }; if ( isHostObject(docEl, 'compareDocumentPosition') ) { contains = function(element, descendant) { /* DOCUMENT_POSITION_CONTAINS = 0x08 */ return (descendant .compareDocumentPosition(element) & 8) === 8; }; } else if ( isHostObject(docEl, 'contains') ) { contains = function(element, descendant) { return element !== descendant && element.contains(descendant); }; } Performance Fork like Robots

7. var contains = function(element, descendant) { while ( descendant = descendant.parentNode ) { if (descendant === element) return true; } return false; }; if ( isHostObject( docEl , 'compareDocumentPosition' ) ) { contains = function(element, descendant) { /* DOCUMENT_POSITION_CONTAINS = 0x08 */ return (descendant .compareDocumentPosition(element) & 8) === 8; }; } else if ( isHostObject(docEl, 'contains') ) { contains = function(element, descendant) { return element !== descendant && element.contains(descendant); }; } Performance Fork like Hobbits

12. NWMatcher Chrome 1+ Firefox 1.5+ IE 6+ Opera 9.0+ Safari 2.0+ Legacy Chrome 1+ Firefox 1.5+ IE 6+ Opera 9.25+ Safari 2.0.4 + Sizzle Chrome 1+ Firefox 2.0+ IE 6+ Opera 9.0+ Safari 3.0+ Prototype 1.6.1+ * 1.6.0.3 supports Safari 2.0+ Compatible Source ▪ Compatible ▪ Possible Compatibility ▪ Failed Compatibility Browser Support Selector Engines

13. E E#fooId E.fooClass E F E > F E + F F ~ F F[foo] F[foo=&quot;bar&quot;] E[foo^=&quot;bar&quot;] E[foo$=&quot;bar&quot;] E[foo*=&quot;bar&quot;] E[foo~=&quot;bar&quot;] E[foo|=&quot;en&quot;] E:root E:empty E:nth-child(n) E:nth-of-type(n) E:nth-last-child(n) NWMatcher Sizzle Prototype 1.6.1+ E:nth-last-of-type(n) E:first-child E:last-child E:only-child E:first-of-type E:last-of-type E:only-of-type E:not(s) E:active E:focus E:enabled E:disabled E:checked E:link E:visited E:target E:lang(t) E:nth-last-of-type(n) E:first-child E:last-child E:only-child E:first-of-type E:last-of-type E:only-of-type E:not(s) E:active E:focus E:enabled E:disabled E:checked E:link E:visited E:target E:lang(t) E:nth-last-of-type(n) E:first-child E:last-child E:only-child E:first-of-type E:last-of-type E:only-of-type E:not(s) E:active E:focus E:enabled E:disabled E:checked E:link E:visited E:target E:lang(t) Not Supported ▪ Supported ▪ Not Supported + Failed Compatibility E E#fooId E.fooClass E F E > F E + F F ~ F F[foo] F[foo=&quot;bar&quot;] E[foo^=&quot;bar&quot;] E[foo$=&quot;bar&quot;] E[foo*=&quot;bar&quot;] E[foo~=&quot;bar&quot;] E[foo|=&quot;en&quot;] E:root E:empty E:nth-child(n) E:nth-of-type(n) E:nth-last-child(n) E E#fooId E.fooClass E F E > F E + F F ~ F F[foo] F[foo=&quot;bar&quot;] E[foo^=&quot;bar&quot;] E[foo$=&quot;bar&quot;] E[foo*=&quot;bar&quot;] E[foo~=&quot;bar&quot;] E[foo|=&quot;en&quot;] E:root E:empty E:nth-child(n) E:nth-of-type(n) E:nth-last-child(n) Legacy Selector Engines Selector Support

15. CSS 3 Selector Tests: Legacy Selector Engines

16. CSS 3 Selector Tests: Sizzle Selector Engines

17. CSS 3 Selector Tests: NWMatcher Selector Engines

19. Performance [ higher score is better ] Selector Engines

20. Performance [ higher score is better ] Selector Engines

35. FuseJS Performance [ lower score is better ]

36. FuseJS Performance [ lower score is better ]

37. FuseJS Performance [ IE8 - lower score is better ]

38. FuseJS Performance [ lower score is better ]