core/scope.js
function(node, callback, depth) {
			if (this.isSkipped(node)) {
				return;
			}

			var childNode,
				childNodes = node && node.childNodes || [];

			depth = (depth || 1);

			for (var n = 0, len = childNodes.length; n < len; n++) {
				childNode = childNodes[n];

				// callback can return false to stop recursive
				if (callback(childNode, depth) !== false) {
					this.walk(childNode, callback, depth + 1);
				}
			}
		}
function(node, callback, depth) {
			if (this.isSkipped(node)) {
				return;
			}

			var childNode,
				childNodes = node && node.childNodes || [];

			depth = (depth || 1);

			for (var n = 0, len = childNodes.length; n < len; n++) {
				childNode = childNodes[n];

				// callback can return false to stop recursive
				if (callback(childNode, depth) !== false) {
					this.walk(childNode, callback, depth + 1);
				}
			}
		}
function ( node , callback , depth ) { if ( this . isSkipped ( node ) ) { return ; } var childNode , childNodes = node && node . childNodes || [ ] ; depth = ( depth || 1 ) ; for ( var n = 0 , len = childNodes . length ; n < len ; n ++ ) { childNode = childNodes [ n ] ; // callback can return false to stop recursive if ( callback ( childNode , depth ) !== false ) { this . walk ( childNode , callback , depth + 1 ) ; } } }
call callback for each child of node
call callback for each child of node