dc3k posted:

everything in linux is a file
everything in javascript is a god drat nightmare

GABA ghoul posted:

I think there is a very clever solution for this that could save a lot of work

code:

if (number < 0)
 number = int.Parse(number.ToString().Replace('-', ''))

RPATDO_LAMD posted:

what yall really need is some solid mathematical background for your IsEvens

Python code:

def isEven(x):
    return not isRelativelyCoprime(x, 2)
    
def isRelativelyCoprime(a, b):
    if b > a:
        a, b = b, a
    # if two integers a and b are coprime to each other, then
    # for all integers i and j,
    # b*i % a == b*j % a implies i % a == j % a.
    for i in range(0, a):
        for j in range(i + 1, a):
            if (i * b) % a == (j * b) % a:
                if i % a != j % a:
                    return False # found a counterxample!
    return True

it uses modulos, and it only takes quadratic time to run!

ultrafilter posted:

Foxfire_ posted:

I don't think I hate this that much? it's icky, but it's also plain what it does and how it works.

(I do hate that resume() returns 0 on both the first iteration and after it's finished)

Foxfire_ posted:

I don't think I hate this that much? it's icky, but it's also plain what it does and how it works.

(I do hate that resume() returns 0 on both the first iteration and after it's finished)

Soricidus posted:

The problem with it is that having a case statement in the middle of a loop is the kind of thing that might plausibly be undefined behavior or a compiler-specific extension. It’s obvious what the code intends to do, but it’s not a common idiom, so unless you’re familiar with the trick, it’s not obvious whether it will actually do that reliably, even if you run it and it seems to work on your machine.

That’s why it’s bad code.

Soricidus posted:

The problem with it is that having a case statement in the middle of a loop is the kind of thing that might plausibly be undefined behavior or a compiler-specific extension. It’s obvious what the code intends to do, but it’s not a common idiom, so unless you’re familiar with the trick, it’s not obvious whether it will actually do that reliably, even if you run it and it seems to work on your machine.

That’s why it’s bad code.

leper khan posted:

what.

duff's device is a little silly, but it's not against the spec

Zopotantor posted:

This is not really Duff's device though; it’s an implementation of a state machine or coroutine. In Duff's device the loop actually has a function, but here it would not really be necessary if the author had properly initialised "i" in the constructor.

efb

Hammerite posted:

I was going to say that it should be ok because no initialization of variables was being skipped, but actually it potentially is if I understand correctly.

The initialization of i to 0 occurs in the for loop header and it ought to run because the state is initialized to "at start" - but having said that, all the properties are public, so the user could construct one of these, then change the state and then call resume() to get it to run without i being initialized? But you could fix that by just initializing i to 0 along with all the other members so I don't know why the author didn't just do that.

Even if the enum member was (say) made private so that you couldn't do that, it seems like it's asking a lot of the compiler to prove that i isn't accessed before it's initialized? You would think the compiler would warn about it.

I guess in C++ both the "switch" and "for loop" language features translate pretty directly to labels and gotos, and it's clear how you convert that code into labels and gotos and it shouldn't cause any problems, so other than the uninitialized variable thing, I don't know how plausible it really is that it would be undefined.

It's a while since I touched C++.

leper khan posted:

what.

duff's device is a little silly, but it's not against the spec

leper khan posted:

case statements in a loop have no issues

RPATDO_LAMD posted:

"this is bad because if you gently caress with internal object state you can put it in an invalid state" is a very "you're holding it wrong" kind of problem to have

Bruegels Fuckbooks posted:

So really gross for no good reason.

Soricidus posted:

it was the kind of thing that looks like it might be against the spec, and is bad code for that reason.

pokeyman posted:

This is me writing any line of C++. "But does this really work the way I think it does???"

Clanpot Shake posted:

I've had to learn Spring recently and a lot of it boils down to "oh just add the @Magic annotation that you have to just know about." I was having compilation issues when I realized that the framework is so opinionated that it matters what you name things.

We're not even building anything complicated, just dumb REST apps.

QuarkJets posted:

Floating point arithmetic is magic

darthbob88 posted:

Do you have any examples of names that Spring finds objectionable? Everything I can find on a quick search just says "We recommend standard Java naming conventions".

ultrafilter posted:

You can get weird behavior even with machine integers. The function that sends x to -x has two fixed points and that means you can't always assume that abs(x) > 0.

quote:

Integer division overflows in one specific case: dividing the smallest negative value for the data type (see Maximum and Minimum Values) by -1. That’s because the correct result, which is the corresponding positive number, does not fit (see Integer Overflow) in the same number of bits.

Jabor posted:

One of the ways to write your database access layer in Spring JPA is to declare an interface with methods like "List<User> findByEmailAddress(String emailAddress);". The method name is used to figure out what database field you're wanting to look up (since there could be many possible String fields in your database).

This works well enough if your queries are very simple and you know that that's what it's doing under the hood - which is unfortunate, because it might just be good enough to prevent you from switching to something that isn't completely insane.