lambda-jam is a sweet.js macro, λ, which is used to create shorthand, anonymous functions with special argument identifiers. Its functionality is inspired by clojure's shorthand function macro, #().
npm install lambda-jam
lambda-jam's real power is derived from its special argument identifiers and the fact that it returns the last expression for you. _1 references the first argument, _2 references the second argument and so on up until _9. Though, the hope is that you're not passing 9 arguments to a function.
var square = λ(_1 * _1);
console.log(square(4)); // 16
var sum = [1, 2, 3].reduce( λ(_1 + _2) );
console.log(sum); // 6
var tweets = [
{viewed: true, msg: "kjadf"},
{viewed: false, msg: "sweet"},
{viewed: false, msg: "js"}
];
var joinedMsg = tweets.filter( λ(!_1.viewed && _1.msg) ).map( λ(_1.msg) ).join('.');
console.log(joinedMsg); // sweet.jsCheck the test suite for a few more examples.
make test