シーケンシャル処理的な

gistfile1.js

var fs = require("fs");

function seq()
{
        var env = new Object();
	for(var i = 1; i < arguments.length; i++)
	{
		arguments[i - 1].nextAction = arguments[i];
	}
	arguments[0].start(env);
}

function Action(func)
{
	this.func = func;
	this.nextAction = null;
}
Object.defineProperty(Action.prototype, "start", {
	value: function(env)
	{
		this.func.call(env);
	}
});
Object.defineProperty(Action.prototype, "next", {
	value: function(env)
	{
		if(this.nextAction)
		{
			this.nextAction.start(env);
		}
	}
});

function _do(func)
{
	var action = new Action(function()
	{
		func.call(this);
		action.next(this);
	});
	return action;
}

function loadFile(name, path)
{
	var action = new Action(function()
	{
		var env = this;
		fs.readFile(path, function(err, file)
		{
			if(err)
			{
				console.log(err);
			}
			else
			{
				env[name] = file;
				action.next(env);
			}
		});
	});
	return action;
}

function main()
{
	seq(
		_do(function()
		{
			console.log("hello");
		}),
		loadFile("foo", "foo.txt"),
		loadFile("bar", "bar.txt"),
		_do(function()
		{
			console.log(this.foo.toString() + this.bar.toString());
		})
	);
}

main();