Member naming

One of the most important things in programming is naming, and this isn't different in code generation; but there often are cases in which names become magic values in different places. For example, here all we want to do is to return a parameter of a function:

FunSpec("returnString") {
    addParameter<String>("text")
    returns<String>()
    addCode("return·%L", "text")
}

However, even in this basic use case, we already have to put the name twice. If we change it for whatever reason or make a mistake copying the name, we have to fix it in two places. Another way is to use the %N placeholder, but, this requires us to store the ParameterSpec somewhere.

val parameterSpec = ParameterSpec<String>("text")
FunSpec("returnString") {
    addParameter(parameterSpec)
    returns<String>()
    addCode("return·%L", parameterSpec)
}

This is already better, because now we only write the name once. Just one issue: now we have this ugly parameterSpec variable. Luckily, the DSL allows us to use the return value of the addParameter function instead!

FunSpec("returnString") {
    val text = addParameter<String>("text")
    returns<String>()
    addCode("return·%L", text)
}

So this is looking already a lot better. In a lot of instances, you can end up writing the name twice, but if the parameter & variable names are identical, you can use property delegation similar to the Gradle Kotlin DSL.

FunSpec("returnString") {
    val text by addParameter<String>()
    returns<String>()
    addCode("return·%L", text)
}

Last modified: 15 September 2023