Review this generated signup registry before it handles production registrations.
Normalize addresses, reject blank or duplicate addresses by returning null, avoid logging personal data, and keep high-volume registration efficient.
kotlin
data class Signup(val email: String)
class SignupRegistry {
private val signups = mutableListOf<Signup>()
fun register(rawEmail: String?): Signup? =
rawEmail?.let { email ->
Signup(email.trim().lowercase())
}?.also { signup ->
println("registered ${signup.email}")
if (signups.none { existing -> existing.email == signup.email }) {
signups += signup
}
}
fun size(): Int = signups.size
}
generated code is illustrative, not from any one model