Chain identities

When manipulating a chain (including Promise), we could always change, at any moment, the chain's API (so its identity) by calling any "identity method".

deep.fs("/my/root")			// identity method 1 : we start a "file system" chain (nodejs) 
.from("myjsonfile.json")		// read a json file
.done(function(success){		// manipulate loaded json
	success.myProp = "hello world";
	//...
})
.restful("myService")		// identity method 2 : we take the "restful chain" API, we keep current success
.post()				// post current success (the maniplated loaded json) to myService
.fail(function(error){
	// handle any error produced somewhere in the chain
});

Chains stack