Is my SO Coffee Mug defective?

Question

I received a really nice SO mug as swag for the choose your own swag contest this year. Everything was working fine until this morning. Was there a patch or update or something?

Here's the relevant code snippet:

if (owner.isCoding() && mug.isEmpty())
{
    mug.fill('coffee');
}

Here's a screenshot of what I'm seeing:

As I've highlighted with an orange arrow, I am coding recursive fractals using Logo. You can see also that my cup is empty. I believe this satisfies both conditions specified in the code snippet I posted above, and yet my cup remains empty.

I checked the console and there are no errors. What gives?

Answer 1

You forgot to hook up dependency injection correctly.

You need one of these:

Answer 2

Classic beginner mistake. The code hasn't been run. So, hold the mug and run ... perhaps to the pantry, where the coffee is.

Answer 3

Your computer checked Wikipedia and XKCD and discovered that "half full" and "half empty" mean the same thing. Now if

0.5*full = 0.5*empty

then

full = empty

So your code made the cup empty, on the assumption that that was the same as making it full.

Answer 4

Assuming your coffee mug isn't playing an April Fools joke on you . . .

This appears to count as undefined behavior. An official source states that (boldface mine)

While no incidents have been reported, the following scenarios might result in undefined mug behavior:

• Owner changing, or non-owner use of mug
• Existential difficulties of owner

I suspect that your existential difficulties have led to your working with Logo. Square fractals are recursive, meaning that any time you try to work with them, you'll get back to somewhere similar to where you started. Therefore, whenever you try to drink coffee and work with them, you'll get back to where you started. . .

Any empty mug.

Answer 5

You are most definitely missing a break statement. That thing won't get filled without a decent break.

Also, the if should be a while, obviously...

while (owner.isCoding() && mug.isEmpty())
{
    break;
    mug.fill('coffee');
}

Answer 6

This line:

mug.fill('coffee');

Does not state the amount of time it takes for the mug to be filled with coffee, or how it's done.

Put the mug, empty, below your pillow at night, and when you'll wake up, it will be full.

Tooth Fairies got some less known relatives, such as Coffee Fairies.

Answer 7

The && operator shorts the circuits, so owner.isCoding() is called but mug.isEmpty() is not. So if you're coding with Legos and you are the one true owner of the mug, it doesn't matter whether your mug is empty, the code will always be called.

The .fill method doesn't do any checking for .isFull() so in your case it looks like the Stack Overflowed and contents was set to 0. You can see using .contents.toLiters() how much is in mug.

I also recommend refactoring the code to make it more efficient. You can do that by reversing the indentation. I think that worked for Mat's Mug.¹

You can find more information about this here.

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¹citation needed

Answer 8

Perhaps they ignored the linker warning: mug was not correctly instantiated.

At least you didn't suffer a core dump. :)

Answer 9

I've finally found a solution for Mac OS X!

Turned out the OS X flavor of Unix doesn't ship with all the required dependencies. The easiest way to install it is via Homebrew.

$ brew install coffee

Strangely the coffee seems to be mildly alcoholic, must be a homebrew issue.

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What we really need is a way to run this from a browser. Maybe I'll try porting it to Coffeescript later.