Hey there. I'm trying to use a method with the fol...

# announcements

[df]

Hey there. I'm trying to use a method with the following signature

inline fun <T> withLoggingContext(map: Map<String, String>, body: () -> T): T {

invoking it like this

withLoggingContext(browserInfo.toMap()) {
                logger.warn { "Payment context provides no customer ip address" }
            }

leads to following compilation error

Error:(28, 13) Kotlin: None of the following functions can be called with the arguments supplied: 
public inline fun <T> withLoggingContext(vararg pair: Pair<String, String>, body: () -> ???): ??? defined in mu
public inline fun <T> withLoggingContext(pair: Pair<String, String>, body: () -> ???): ??? defined in mu
public inline fun <T> withLoggingContext(map: Map<String, String>, body: () -> ???): ??? defined in mu

Help is appreciated

[Stephan Schroeder]

The logger doesn't really take a lambda, does it?? Shouldn't it be logger.warn ( "Payment context provides no customer ip address" )

[df]

The logger is just fine. It's defined as

actual fun warn(msg: () -> Any?)

[df]

it complains about the invocation of withLoggingContext

[Stephan Schroeder]

what's the return type of the logger? because the withLoggingContext probably wants to return that.

[Stephan Schroeder]

hmm, Unit should handle this correctly 🧐

[Stephan Schroeder]

does browserInfo.toMap() return a Map<String,String>?

[df]

Sorry sometimes I'm just blind. It's

Map<String,String?>

. Is there a neat utility function that turns Map<String,String?> into Map<String,String> like listOfNotNull for lists?

[df]

Thanks already!

[Stephan Schroeder]

map.entries.mapNotNull {(key, value)->value?.let{key to it}}.toMap()

[df]

thanks

[Stephan Schroeder]

i got the syntax a bit wrong 😅 it's .mapNotNull{key, value->value?.let{key to it}}.toMap()

[df]

no worries, already got it

[df]

And found this https://youtrack.jetbrains.com/issue/KT-4734

[Stephan Schroeder]

without entries Kotlin wants type annotations. so back to `

map.entries.mapNotNull{(key, value)->value?.let{key to it}}.toMap()

[Stephan Schroeder]

filterNotNullValues and filterNonNullKeys : those would be nice! The ticket is already two years old though.

[Stephan Schroeder]

here's the implementation for the first:

fun <K: Any, V> Map<K,V>.filterNotNullValues() = this.entries.mapNotNull{(key, value)->value?.let{key to it}}.toMap()

[df]

I know. I just pointed to it because there the comments already include the implementations for the requested methods

[Stephan Schroeder]

where's the fun in that 😂 And here's the implementation that can only be invoked on Maps where the value is actually nullable:

fun <K: Any, V:Any> Map<K,V?>.filterNotNullValues(): Map<K,V> = this.entries.mapNotNull{(key, value)->value?.let{key to it}}.toMap()