Callback wrapper that implements trampoline with try/catch

tryCatchTrampo.js

// callback wrapper for trampoline
var depth = 0;
var maxDepth = 100;
var marker = {};

function trampo(cb) {
	return function(e, r) {
		var d = depth++;
		try {
			if (depth === maxDepth)
				throw [marker, cb, e, r];
			else
				cb(e, r);
			depth = d;
		} catch (ex) {
			depth = d;
			if (ex[0] === marker && depth == 0) 
				ex[1](ex[2], ex[3]);
			else
				throw ex;
		}
	}
}

// test program 
function fibo(async, i, cb) {
	cb = async ? delay(cb) : trampo(cb);
	if (i <= 1) cb(null, 1);
	else fibo(async, i - 1, function(e, r1) {
		if (e) return cb(e);
		fibo(async, i - 2, function(e, r2) {
			if (e) return cb(e);
			cb(null, r1 + r2);
		});
	});
}

function delay(cb) {
	return function(e, r) {
		process.nextTick(function() {
			cb(e, r)
		});
	}
}

fibo(false, 20, function(e, r) {
	if (e) throw e;
	console.log(r);
})

Gotcha: if you have try/catch in your code, you must rethrow the special trampoline exception in your catch clauses. You can do it with if (Array.isArray(ex)) throw ex;.