If you have a function foo() that takes a callback as an argument i.e. something like: foo(..., function (n) { // closure over q, r, s }); Then what

If you have a function foo() that takes a callback as an argument i.e. something like: foo(..., function (n) { // closure over q, r, s }); Then what you can do is create a separate function, bar() that takes q, r, s as an argument, and returns a function: function bar(q, r, s) { return function(n) { // still has dependency on q, r, s } } Once you have bar(), the foo() call above can be written as: foo(..., bar(q, r, s)); and you save one level of nesting. (This also makes the dependencies explicit, which is helpful.) The main loop of https://github.com/ithinkihaveacat/node-fishback/blob/ce5f9c308db6a12f15fb0d790c53dfb2f60eaf9c/lib/fishback.js#L313 https://github.com/ithinkihaveacat/node-fishback/blob/ce5f9c... does quite a lot of this, if you want a real example.