Maybe some day I'll understand the code I wrote...?

point-free-promises.js

// functional helpers
var before = function() {
	var functions = Array.prototype.slice.call(arguments, 0);
	return function() {
		var that = this;
		var args = Array.prototype.slice.call(arguments, 0);
		var ccat = [].concat.bind([]);
		return curry(tail, functions.map(
			compose(
				curry(invoke.apply, that),
				(
					curry(compose, rcurry(aritize, 1))
					(rthunkify(args))
				)(ccat)
			)
		))();
	};
}

// old before
// var before = function() {
// 	var args = Array.prototype.slice.call(arguments, 0);
// 	return function() {
// 		f.apply(this, arguments);
// 		return g.apply(this, arguments);
// 	};
// }

// SIMPLIFYING STRUCTURES

// function(f) {
// 	return curry(g)();
// }

// curry(g)

// function(f) { 
// 	return compose(z)(f);
// }

// compose(z)

var wrap = function(x) { return '(' + x + ')'; }

var head = function(arr) { return arr[0]; };
var tail = function(arr) { return arr[arr.length-1]; };

var I = function(x) { return x; };
var args = function() { return Array.prototype.slice.call(arguments); };

var getValue = function(obj, key) { return obj[key]; }

var invoke = function(f) {
	var partials = Array.prototype.slice.call(arguments, 1);
	return f.apply(this, partials);
}
invoke.apply = invoke.apply.bind(invoke);

var curry = function(f) {
	var partials = Array.prototype.slice.call(arguments, 1);
	return f.bind.apply(f, [].concat(this, partials));
}

var rcurry = function(f) {
	var that = this;
	var partials = Array.prototype.slice.call(arguments, 1);
	return function() {
		var args = Array.prototype.slice.call(arguments);
		return f.apply(that, [].concat(args, partials));
	};
};

var aritize = function(f, n) {
	return function() {
		var args = Array.prototype.slice.call(arguments, 0, n);
		return f.apply(this, args);
	}
}

// thunkify(log)
// curry(curry, log)
var thunkify = curry(curry, curry);
var rthunkify = curry(rcurry, rcurry);

var compose = function(f, g) {
	var that = this;
	return function() {
		return f(g.apply(that, arguments));
	}
}

var sequence = function() {
	var args = Array.prototype.slice.call(arguments, 0);
	return compose.apply(this, args.reverse());
};

// lambda functions

// var getUser = new Promise(function(cb) {
//    cb({ name: 'raine' });
// });

// var getName = function(user) {
//  return user.name;
// };

// var log = console.log.bind(console);

// var say = function(str) {
//   return function(val) {
//    console.log(str);
//    return val;
//  };
// }


// point-free style
var getUser = new Promise(aritize(rcurry(invoke, { name: 'raine' }), 1));
var getName = rcurry(getValue, 'name');
var log = console.log.bind(console);

var say = sequence(
	thunkify(aritize(log, 1)),
	rcurry(before, I)
);

getUser
	.then(say(1))
	.then(log)

getUser
	.then(say(2))
	.then(getName)
	.then(say(3))
	.then(log)

undefined