I know people are really split on them but even in...

# announcements

[kevinmost]

I know people are really split on them but even in Java, I personally prefer while (true) with a break over crazy assignments in the while condition:

var len: Int = 0
while (true) {
  len = def.deflate(buf, 0, buf.size)
  if (len <= 0) break
  ...
}

[araqnid]

assignment in the condition was something I got used to in C 25 years ago, old habits die hard (that's my excuse, anyway)

[cedric]

For this kind of loop, I think performance trumps everything so I have no shame writing whatever code will slurp these bytes in as fast as possible.

[kevinmost]

@cedric which would be more performant, actually? Assignment in the condition?

[kevinmost]

I assume so just because it's what I generally see in SDK methods that use while loops

[elizarov]

I bet there would be no perf difference.

[evanchooly]

I view while(true) { … break; } as a code smell, personally. don’t make me parse the entire block to find out what my exit criteria are.

[cedric]

It is a code smell but my point here is that avoiding that code smell might lead to a performance smell

[cedric]

In this particular case, I’d pick whichever proves to be faster even if it leads to slightly less readable code

[cedric]

while probably beats all the other alternatives and I’m guessing while(true) + break might beat while(keepGoing), but that’s just a gut feeling

[kevinmost]

@evanchooly I personally feel like it's way more readable if there's a clear guard case at the top of the while loop than trying to read a nested gross while ((len = obj.someLongMethodThatObscuresTheIntentOfThisCondition()) > 0) { ... } conditional statement

[kevinmost]

Languages like Rust have loop { ... } for this case, which is basically an alias for while (true) { ... }

[evanchooly]

but this is kotlin so you could always write an extension function forEach(int) { } to hide that all away

[karelpeeters]

repeat(int) { ... } exists in the stdlib aleady.

[kevinmost]

and this is Kotlin so you can't use an assignment as an expression like that anyway 😆

[kevinmost]

I'm talking about Java really

[evanchooly]

ewww. 😉

[cedric]

repeat(Long.MAX_VALUE) { // should be big enough

[karelpeeters]

I just died inside.

[kevinmost]

I mean you could just write:

inline fun loop(block: () -> Unit) {
  while(true) { block() }
}

🙂

[kevinmost]

could even make that function return Nothing

[karelpeeters]

Well you can still return@loop, right?

[kevinmost]

the actual while (true) would still continue though, wouldn't it? 🤔

[evanchooly]

labeled breaks make my butt itch

[deviant]

repeat(Long.MAX_VALUE) {
    repeat(Long.MAX_VALUE) {  // if 1 repeat isn't enough
    }
}

[araqnid]

reminds me of the infamous “waitAndDoubleRetry” scheme we found lurking in an old codebase once…