e g ``` thing a = test b = wat ``` kotlinlang #announcements

09/20/2017, 4:34 PM

thing {
    a = "test"
    b = "wat"
}

09/20/2017, 8:27 PM

In this case you'd want

thing

to have signature

fun thing(body: MyBuilder.() -> Unit)

MyBuilder

has properties

09/20/2017, 9:20 PM

If I knew it would have the properties a and b that would be fine, but I don't know that

This is where atoms would be really useful 😕

09/20/2017, 9:40 PM

You could define an infix function that automatically adds the declaration to a collection in the builder

but you wouldnt be able to use '='

09/20/2017, 9:43 PM

I could get away with

thing {
    it[:a] = "wat"
}

Id prefer not to refer to strings all the way thru

09/20/2017, 9:56 PM

fun buildAThing() {
    thing {
        "a" equals "test"
        "b" equals "wat"
    }
}

fun thing(function: Builder.() -> Unit) {
    Builder().function()
}

class Builder {

    val declarations = mutableListOf<Declaration>()

    infix fun String.equals(other: String): Declaration = Declaration(Term(this), Value(other)).apply { declarations.add(this) }
}

class Term(val name: String)
class Value(val value: String)

class Declaration(term: Term, value: Value)

09/20/2017, 9:56 PM

Yea I knew that that was a possibility. But I wanted the DSL to be as typesafe as possible.

09/20/2017, 10:02 PM

Can reified generics help?

09/20/2017, 10:04 PM

Not sure how here

09/20/2017, 10:33 PM

So, what determines which properties are ok? Are all properties ok?

09/20/2017, 10:38 PM

any valid kotlin identifier is an okay property and any primative is an ok value

09/20/2017, 10:38 PM

How do you expect type safety then? 😄

You kinda need just a

Map<String, Any?>