Understandable. I guess you could always define a float iterator. :V

i had to google what python/haskell did before it became clear to me what the issue was

If you really wanted it, I bet you could override or subclass IntProgression and allow floats for the increment.

The kotlinlang.org/docs/reference/ranges.html page talks about the different items. Since there's multiple-dispatch supported, I bet you could make the range convert select floats with ease.

^ Entirely speculation. I've not tried it.

Plus, if you make "FloatRangeTo" you can refer to it as 'frt', pronounced 'fart'.

hahah that last bit makes it worth it 🙂

"Why are we only getting 15fps?" "Engine has a big frt in the middle."

"Can we do lots of little frts instead?" "Yeah, but we'll get GC fragmentation and weird blocks."

I’m currently reading through the coroutines documentation and trying to get an understanding of it all. I didn’t notice any explicit threading going on. Where is that handled?

Please join #coroutines Threading is orthogonal to coroutines. You can run any number of coroutines in a single thread, but you can also define your own dispatching strategies.

Thanks!

I’m new to Kotlin. Can someone explain why this code:

fun main(args: Array<String>) { val ages: Map<String, Int> = hashMapOf("Dave" to 26, "Lynne" to 29) println(ages["Dave"]) println("$fname is ${ages["Dave"]} years old") if (ages["Dave"] < 22) println("Young") else println("Old") if (ages["Dave"]?.compareTo(22)) println("Young") else println("Old") }

… produces this error: Error:(7, 20) Kotlin: Infix call corresponds to a dot-qualified call 'ages["Dave"].compareTo(22)' which is not allowed on a nullable receiver 'ages["Dave"]'. Use '?.'-qualified call instead

ages[”Dave”]

can return

null

. The type is

Int?

not Int.

I thought each element of a map would be non-nullable by default?

The elements are non-nullable, but looking up by a key may not find an element

even though the key is a constant, and contained in the

ages

map, the Kotlin type checker cannot track that

for example,

ages[”Bob”]

would return

null

ages[”Dave”]

returns

26

(an Int)

But I specified the type, ie. Map<String, Int>

what do you expect it to return for an element that doesn’t exist in the map?

But not all strings map to an Int

so the signature of the indexing method is

fun get(key: String): Int?

to reflect that some Strings do not map to a value in the map

The value of that key: 26

if the key didn’t exist, the call would need to throw a NPE because it couldn’t stuff the null in to that non-null int

like Nat mentioned, you are looking in the wrong direction, the function for extracting an element from a map returns an optional

You can force value that you look to be not null with the

!!

operator, which will throw a NullPointerException if it is actually null