Hey G
Glad someone is paying attention ;-) Well spotted.
Doing a permutation of the people ought to make it fairer. Which is important if your name is near the front of the alphabet. Will update the post. Thanks!rota = do
g<-newStdGen
h<-newStdGen
return . sort $ zipWith (++) (cycle $ shuffle' ps (length ps) h) (shuffle' js (length js) g)
Another
code block
Definitely 'a Hacktionlab';, and not ';an Hacktionlab'. Unless you're common, and drop your 'h';. In which case, I will shoot you https://www.englishclub.com/pronunciation/a-an.htm
Don't understand Haskell, but if you're cycling through the people list, and the jobs list does not divide exactly by the number of housemates, does this mean that housemates earlier in the array will end up with more tasks per month than those later in the array?
Comparison craziness Yeah, because you don't know the difference between equality (==) and strict equality (===) operators, right?
The type of not a number is, well, a number. Sensible. It's a subtype of number.
Well at least that means it ought to be equal to itself, right? Yeah, I agree this is weird, but it's just intended and specified like this in the ECMA specification.
So, what is a string then? String is a primitive type, it's not an object. So the instanceof operator can't be used.
How about a really big number first of all. Wait. What? Hopefully small numbers make more sense. It's a standard float number specified by IEEE 754. You can't expect it will handle so huge numbers. It can't also be precise when counting with decimal numbers, because some of then can't be expressed using the binary system.
I guess not. I bet that max is still bigger than min though. Maximal and minimal numbers can be accessed using the Number.MIN_VALUE and Number.MAX_VALUE. These function return minimal and maximal numbers of the given numbers (using arguments). So for example Math.min(1, 2) gives 1. The algorithm is also using the Infinity number as a maximum value for comparing. That's why Math.min() without arguments return Inifinity. It's its initial value.
Calling + on an empty array and an empty array gives the empty string. Who knew? The plus operator isn't used for concatating arrays. It's used for adding strings and numbers. Deal with it.
An empty object and an empty array gives, ummm, 0.
That's not actually and object. {} + [] means empty block and then +[] which converts the empty array to number. However ({} + []) or variable = {} + [] really means what you would expect and returns the same as the example above.
Whereas an empty object and an empty object is not a number. Which is true, I suppose. The same problem. When you have a real expression both are objects and so the result is "[object Object][object Object]".
Ah. It looks like true is equal to one. I’ll just check.
Wow, now you discovered the strict equality operator. That means true == 1 will also surprise you?
See if you can work out what this will evaluate to Why would you write anything like this in a real app? Every language supports a simillar bullshit.
(!+[]+[]+![]).length = 9
because: "truefalse".length = 9
So where does "truefalse" come from?
+[] = 0 !0 = true true+[] = "true" ![] = false "true"+false = "truefalse"
Yeah, it's crazy, but if you're mixing types and doing this sort of crazy thing you deserve every headache you get.
hey allthetime, Anon,...wtf? -- allthetime
Now, as to why those were the decisions they made, your guess is as good as mine - but I guess they're just as reasonable as any other decision for when you ask for the max or min of an undefined value. -- Anon
It's actually more sensible than you might think.
It is because Math.min() and Math.max() can be used as functions over an array. Think of it as being a bit like the sum and product functions (I implement these in a later comment). If you've ever done any group theory the following should be familiar.
If you call sum on an empty collection, you'd expect it to return 0, which is the "identity" for + or "additive identity". That is
a + 0 == a and 0 + a == a
If you call product on an empty collection you want it to return 1, which is the "multiplicative" identity. That didn't seem obvious until I thought about it like this
a * 1 == 1 and 1 * a == a
In the same way you want max to return an identity function for "max-ness" so that
max a ? == a and max ? a == a
I find it easier to compare with + and * if I shift the max to the middle thus
amax? == a and ?maxa == a
In order for this to always be true, max() has to return something guaranteed to be smaller than any other number — hence negative Infinity (aka -∞, ⧞ or -Infinity). -∞ is the identity of max in the same way that 0 is the identity of + or 1 the identity of *.
So now we have
amax-∞ == a and -∞maxa == a
In the same way the identity for min has to be bigger than any other number so we get
aContinued in next comment…min∞ == a and ∞mina == a
…continued from previous post.
I realized that js doesn't actually have sum or product fuctions, so let's build them and then show how we could implement min or max in a functional style. Here are the sum and product callbacks, which we will need shortly.js> sum = function(total, num){ return total + num }
With these, an identity, and the js Array.reduce function we can now sum or product an array. We will also check they are right by comparing with writing them out longhand.
(function (total, num){ return total + num })
js> product = function(total, num){ return total * num }
(function (total, num){ return total * num })js> [1,3,5,7].reduce(sum,0)
16
js> [1,3,5,7].reduce(sum,0) == 1+3+5+7
true
We can verify that all sorts of trouble ensues if we give the wrong identity to our reducesjs> [1,3,5,7].reduce(sum,1) == 1+3+5+7
Let's do the same thing with max and check it works as expected
false
js> [1,3,5,7].reduce(sum,1)
17
js> [1,3,5,7].reduce(product,0) == 1*3*5*7
false
js> [1,3,5,7].reduce(product,0)
0js> max = function(total, num){ return total>=num ? total : num}
(function (total, num){ return total>=num ? total : num})
js> [1,3,5,7].reduce(max,‐Infinity)
7
Now what would happen if the identity were Infinity?js> [1,3,5,7].reduce(max,Infinity)
So there you have it. Not entirely crazy after all ;-)
Infinity
Some insight as to why Math.min() > Math.max()
> Math.max() -Infinity > Math.min() Infinity...wtf?
Thanks for sharing the screencast lolkittens I was LOLing in recognition :-) Thanks also for your technical explanations. Good stuff...
You're welcome Charlie. Given the number of tasks I may have just saved you in your house, I wonder if you'd consider repaying me by picking up one - just one - of my household's tasks over the next year. I've used you script* and made is specific to my household ...
ps = ["Me"]
js = [ "Clean entire flat"]
* I'm also not sure the script is working - every week it seems to be emailing me, and nobody else. Is there no justice in this world?