lisp.js/misc/trampoline.js

A tiny lisp interpreter

function plus(a, b) {
    return a + b;
}

function plus_cont(a, b, then) {
    return trampolineBounce(function() {
        return then(a+b);
    });
}

function trampolineBounce(func) {
    return { type: "bounce", func: func };
}

function runTrampoline(func) {
    var step = func(function(result) {
        return { type: "result", result: result };
    });
    while (step.type === "bounce")
        step = step.func();
    return step.result;
}

var onePlusTwoPlusThree = runTrampoline(function(then) {
    return plus_cont(1, 2, function(onePlusTwo) {
        return plus_cont(onePlusTwo, 3, function(result) {
            return then(result);
        });
    });
});

console.log(onePlusTwoPlusThree);