Show HN: Fully-featured Nil interpreter in less than 1 line of JavaScript

It's a metacircular evaluator. Written in Nil, surely.

Sadly I couldn't get this down to less than one line, but here's how you can do this to implement a proper Nil interpreter

    Function.prototype.apply = Function.prototype.call = function () {};

Insert this subtly somewhere into other people's code to ruin their day/week

The title is ambiguous but it's arguable that no JavaScript at all is "less than one line of JavaScript".

> Now, if you could override Function.prototype to just function(){}

Function.prototype is already set to an empty function by default (evaluate Function.prototype() and you get 'undefined'), so I am not sure this has the consequences you think it does.

When you call a function object, let's say f, Javascript looks for an internal method on f called [[Call]] and calls it. If one doesn't exist, an error is thrown. The internal property [[Prototype]] of f is not ever considered, although you are right that it would be equal to Function.prototype.

EDIT: Despite what I think, executing phpnode's code in my node.js REPL instantly crashes it, so I guess there is more going on here.

Technically, javascript already has built-in a Nil interpreter: the void keyword

a form with onsubmit="" technically executes a zero length javascript program.

Is an empty string less than one line of code? Or is it one line of zero length?

There was also a story yesterday titled "Hello World in 1 line of Javascript" (which I think is now dead).

I've considered doing JIT compilation to JavaScript and adding IntelliSense, but that'd require another 0 lines of code and I'm worried it might ruin the beautiful simplicty of it.

True, but he seems to have a moral conviction that proprietary software is wrong, and hence doesn't like JS much as it is a vector for automatically download and executing proprietary software. So I was exaggerating, but there is some truth to my words.

But it is interesting that the title change resulted in it making it to the front page.

Nah, I think the fact you can easily try it in your browser and the additional explanation helped it. ;)

The submitted page actually well predates this "30 lines" fad, I just realised it might be an effective parody today. The joke works better in HTML form, as it takes longer to see it.

"no JS present" = "less than 1 line of JavaScript"

No?

Easily fixed:

    <script type="text/javascript"></script>