Experimenting with the idea of copying Object slices and creating composite Objects via slices

js_object_copy_slice.js

var util = require("util");

var o = {
	p1: {
		c1:[{l1:"a"}, {l2:"b"}],
		c2:{l3:3, l4:4}
	},
	p2: {foo:"bar"}
};
process.stdout.write("// Original object:\n");
process.stdout.write(util.inspect(o,false,10,true) + "\n\n");


function copyAtPath(src, path, dst) {
    var srcNode = src,
		dstNode = dst;
    for (var i = 0, l = path.length - 1; i < l; ++i) {
        var key = path[i];
        if (!dstNode.hasOwnProperty(key))
			dstNode[key] = srcNode[key] instanceof Array ? new Array(srcNode[key].length) : {};
        srcNode = srcNode[key];
		dstNode = dstNode[key];
    }
    dstNode[path[i]] = srcNode[path[i]];
    dstNode[path[i]] = srcNode[path[i]];
}

var o2 = {};
["p1.c1.1", "p1.c1.0", "p1.c2", "p2"].forEach(function(path){
	copyAtPath(o, path.split("."), o2);
	process.stdout.write("// Copy after copyAtPath(" + JSON.stringify(path) + "):\n");
	process.stdout.write(util.inspect(o,false,10,true) + "\n\n");
});