kotlinlang #stdlib

If two instances of Random are created with the same seed, and the same sequence of method calls is made for each, they will generate and return identical sequences of numbers. In order to guarantee this property, particular algorithms are specified for the class Random. Java implementations must use all the algorithms shown here for the class Random, for the sake of absolute portability of Java code.

kirillrakhman

11/16/2016, 8:51 AM

@ilya.gorbunov I was looking at https://github.com/JetBrains/kotlin/commits/rr/stdlib/minmax and I was wondering, if min/max is really needed when stdlib already has

coerceAtLeast/AtMost

voddan

11/16/2016, 10:04 AM

IMHO

coerceAtLeast

is super useful to limit something, like

boo().bar().zuzz().courrceAtLeast(5.0)

voddan

11/16/2016, 10:05 AM

But when you have 2 short or 2 long expressions, anything but

max

is confusing

👍 1

☝️ 1

dimsuz

11/16/2016, 12:42 PM

@cleiter

it's right in the javadoc of ⁠⁠⁠⁠Random⁠⁠⁠⁠

it doesn't state explicitly if this is true for one jvm launch or across launches and even architectures...

ilya.gorbunov

11/16/2016, 2:22 PM

@kirillrakhman Although

minOf

and

coerceAtMost

perform the same operation in a nutshell, their usecases are totally different, see @voddan's answer

dean

11/21/2016, 4:50 PM

https://youtrack.jetbrains.com/issue/KT-14911

11/29/2016, 5:40 AM

was there discussion of potential new methods for updating individual items in a List? i feel like i remember it but history doesn't go back that far and i can't find anything on KEEP or KT

11/29/2016, 5:41 AM

e.g., updating a single property of a data object at index N of a List isn't very elegant

11/29/2016, 5:41 AM

best i have so far is

MutableList(orig).apply { set(index, get(index).copy(prop = newProp)) }

11/29/2016, 5:44 AM

would love

orig.updateIndex(index) { it.copy(prop = newProp) }

or something

gildor

11/29/2016, 5:51 AM

@jw I know only about this proposal - https://github.com/Kotlin/kotlinx.collections.immutable/blob/master/proposal.md

11/29/2016, 5:54 AM

hmm that might be it

11/29/2016, 5:54 AM

thanks

11/29/2016, 5:55 AM

i'm not sure how common of an operation this is to potentially warrant inclusion in the stdlib or not for plain 'ol List though

gildor

11/29/2016, 5:55 AM

@jw Nevertheless, no updateIndex there, only add/remove/put

11/29/2016, 5:55 AM

true

gildor

11/29/2016, 6:01 AM

Current implementation uses http://pcollections.org/ and pcollection API doesn’t have updateIndex too - https://github.com/hrldcpr/pcollections/blob/master/src/main/java/org/pcollections/PCollection.java

rocketraman

11/29/2016, 3:52 PM

@jw Yeah I think that was a discussion I had brought up a while back. I hate that the Slack history isn't complete. Somebody needs to build a slack history-keeper bot. I believe I ended up using your option #1.

rocketraman

11/29/2016, 3:53 PM

Actually looking at my source, I made this extension function:

Copy code

inline fun <T> List<T>.mutate(f: MutableList<T>.() -> Unit): List<T> {
  val mutableList = this.toMutableList()
  f(mutableList)
  return mutableList
}