I always found that I have a difficulty to underst...

# getting-started

[Ayden]

I always found that I have a difficulty to understand the documentation from Kotlin website.
inline fun <T, R> with(receiver: T, block: T.() -> R): R (source)

I don't really understand what is this trying to explain although I have read through the explanation.
I know T might stands for Type but what does R stands for? Run?

The receiver is the argument we pass into it?
What is block?

R i would assume it is the result then.
Am I right?

[diesieben07]

Both T and R are type variables: https://kotlinlang.org/docs/reference/generics.html
The names do not really mean anything in this context, usually people name their first type parameter T and then continue down the alphabet.

[diesieben07]

This is an arguably non-optimal naming scheme though

[Lucas Ł]

Would that be more clear for you?
inline fun <TParam, TResult> with(receiver: TParam, block: TParam.() -> TResult): TResult

[Uzi Landsmann]

I find this article helpful: https://ask.ericlin.info/post/2017/06/subtle-differences-between-kotlins-with-apply-let-also-and-run/

[Ayden]

If I read through the documentation, how to interpret it?

inline fun functionName<T, R>(parameter: T) -> TResult

Something similar like this?

[Lucas Ł]

it has nothing to do how the documentation is written
and your example won't even compile

read about generics first like @diesieben07 mentioned
https://kotlinlang.org/docs/reference/generics.html