Enum

Represents a value chosen from a predefined enum.

• Kotlin Definition: EnumDefinition
• Kotlin Value: IndexedEnum
• Maryk Yaml Definition: Enum

Usage options

• Value
• Map key or value
• Inside List/Set

Validation Options

• required - default true
• final - default false
• unique - default false
• minValue - default unset. Minimum value
• maxValue - default unset. Maximum value

Other options

• default - the default value to be used if value was not set.
• enum - defines the enum can contain

Examples

Example of an Enum definition

Kotlin enum version

enum class Role(override val index: UInt, override val alternativeNames: Set<String>? = null): IndexedEnumComparable<Role> {
    Admin(1u),
    Moderator(2u),
    User(3u);

    companion object: IndexedEnumDefinition<Role>(Role::class, { entries })
}

Sealed class version

sealed class Role(index: UInt): IndexedEnumImpl<Role>(index) {
    object Admin: Role(1u)
    object Moderator: Role(2u)
    object User: Role(3u)

    companion object: IndexedEnumDefinition<Role>(Role::class, { listOf(Admin, Moderator, User) })
}

Example of an Enum property definition for use within a Model

It refers to the earlier Kotlin enum definition

val role by enum(
    index = 1u,
    enum = Role,
    required = true,
    final = true,
    unique = true,
    default = Role.User,
    minValue = Role.Admin,
    maxValue = Role.User
)

Example of a separate Enum property definition

It refers to the earlier Kotlin enum definition

val def = EnumDefinition(
    enum = Role,
    required = true,
    final = true,
    unique = true,
    default = Role.User,
    minValue = Role.Admin,
    maxValue = Role.User
)

Storage Byte representation

The enum index value as two bytes. It is encoded as unsigned short.

A written value’s index must be resolvable by the configured definition. Unknown indexes require an unknownCreator; otherwise validation rejects them before storage. Memory resolves ordinary enum cells in the same way as persistent readers.

Reserving a removed case’s index and name prevents reuse, but stored values still need a reader. Removing that reader requires a model migration. Multi type cases must retain their declared payload definition until their stored values have been migrated.

Indexes above 65,535 are rejected in declarations, value validation, resolution and binary encoding, including unknown enum cases. Existing supported indexes keep the same bytes; no data migration is needed. Previously truncated indexes cannot be recovered from their stored bytes alone.

Transport Byte representation

The enum index value as a VarInt.

String representation

Name of the Enum.