sdiff
gets diff between two strings
var sdiff = ; var source = 'aaabbc';var target = 'aaajjc'; var changes = sdiff; // changes =// [{// start: 0,// length: 3// },// {// value: 'jj'// },// {// start: 5,// length: 1// }]; // send changes by network target === sdiff; // true