gistfile1.js

var data = require('./index');

function wrapper(process){
	var observable, wrapper;

	observable = data();

	wrapper = function(value){
		return arguments.length ? process(observable, value) : observable();
	};

	wrapper.subscribe = observable.subscribe;
	wrapper.bind = observable.bind;

	return wrapper;
}

function map(morphism){
	return wrapper(function(observable, value){
		return observable(morphism(value));
	});
}

function filter(predicate){
	return wrapper(function(observable, value){
		return predicate(value) && observable(value);
	});
}

function unique(){
	var memo;

	return wrapper(function(observable, value){
		if(memo !== value){
			memo = value;
			observable(value);
		}
	});
}