for heap based objects, kotlin already has val so there’s not a huge margin of course

OTOH, with value-types it’s quite clear that a

const

fun parameter would be necessary to not copy the entire value-object. Unless Kotlin goes COW style value-objects without requiring any specification on fun parameter

IMHO, kotlin allows us to specify

inline

and

crossinline

on lambdas for performance reason, It’d be more orthogonal if it allows

const

on params similarly

the key issue is that it's impossible to guarantee the immutability of a heap object in the presence of Java interop

Brian is thinking hard about pattern matching: http://cr.openjdk.java.net/~briangoetz/amber/pattern-match.html

brian does great work.

I noticed

sealed interface Node { }

in that article. 😭 I cannot do that in K yet.

It requires JVM change

Ok, but how is it that much different from

sealed class Node

?

we can make constructor for a class inaccessible from classes other than known inheritors, for interface there is no such guard

Oh, makes sense.

I'll stick to my empty

sealed class

for now. Compile errors due to exhaustiveness save a few seconds when I add new type.

I never checked that, but I was suspecting that it's working like

internal

and you just "couldn't" add subclass in a different module.

"a few seconds" lol

try a few hours of a junior dev debugging your visitor implementation

i just switched from a java based visitor to a kotlin based one because it meant I could have a

when

statement that enumerated all of the node types, and would force a compiler error when a new node type was added. Combine that with a couple other kotlin techniques to reduce boiler plate, and its now enormously difficult to break the new implementation i have in kotlin.

my one request, and i understand the problem in implementing it, is that sealed classes have to be in the, well I'll call it same compilation atom

It does mean that my biggest kotlin file ever, at 700 lines, is just a sealed class with a dozen data class implementations

https://github.com/apple/swift-evolution/blob/master/proposals/0168-multi-line-string-literals.md how often i've been lost in these long strings with mutliple \n and ""

would be cool to see that in kotlin 😄

Seriously?

@sksk Are you being sarcastic, or did you really not know?

wow i learn new things like everyday xD thanks @orangy

i never got the inspection from intellij to convert my large strings to that format ( or i don't remenber getting one )

@sksk you should read through the documentation at http://kotlinlang.org/docs/reference/, you will lear a lot of other useful stuff

@kirillrakhman thanks for the link!

I will create an issue to improve the intentions

there is one to convert a regular string to raw string, but it doesn't handle string concatenations

you can do it in multiple steps, tho