Hey guys! I very like kotlin cause it’s very agile...

# announcements

[Tim Kuzmin]

Hey guys!
I very like kotlin cause it’s very agile for the most situation
f.e. I wanna have postfix version for ternary operator(i understand position of lang-developers about if-else). So, that’s my first solution:

fun <T> Boolean.ternary(first: T, second: T) =
        if (this) first
        else second

Any pro-programmer will tell u that in cases like this
(stringA != null).ternary(stringA!!, stringB!!)
we will have npe(parameters of function calculates before call).

Lets make our function inline and add reified type:

inline fun <reified T> Boolean.ternary(first: T, second: T) =
        if (this) first
        else second

Nice! Now for non-primitives classes we will not have any trouble.
I guess u’ve already understand what I mean. For primitives it doesnt work, cause even for inline function kotlin calculates primitive expressions and then call function. For me it’s looks like a bug. Does anybody know will it be fixed for next versions?

[Dominaezzz]

I think you need a contract.

[Dominaezzz]

I haven't written one myself but you can look at the implementation of requireNonNull for inspiration.

[Dominaezzz]

Actually nevermind, it'll only work if first and second are lambdas.

[Tim Kuzmin]

thank u, will research solution in this area 🙂

[Tim Kuzmin]

Contracts doesnt fix issues this type, it’s not kotlin compiler sugar-fix. This problem as I think is a little bit deeper than it’s seems

[karelpeeters]

Neither inline nor reified have any effect on when the parameters are evaluated, so I don't understand what you're talking about. It doesn't matter whether T is primitive either.

[karelpeeters]

If you want lazy evaluation you definitely need lambda parameters.