I have a function that takes the following as a pa...

# getting-started

[Kevin]

I have a function that takes the following as a parameter:
validator: ValidationContext.(String?) -> ValidationMessage?

So I think I need to provide a function that takes in a ValidationContext and gives out a ValidationMessage, but what is up with the .(String?). I don’t understand what the signature of my function should be.

[kevinmost]

The type of that validator variable is "A lambda where ValidationContext is the receiver, with one parameter of type String? (nullable string), returning a `ValidationMessage?`"

[Kevin]

So that means I would make an extension function on ValidationContext like this? fun ValidationContext.myValidator(myString: String?): ValidationMessage? ?

[Kevin]

oh wait a lambda

[Kevin]

it has to be a lambda?

[Kevin]

so I have to put the parameter in curly braces

[Kevin]

okay it all just clicked, thank you 👍

[karelpeeters]

It doesn't _ have_ to be a lambda, you could also pass a function reference ::myValidator