Context

Syntax

context <Name> {
  <elements>
}

A context is the top-level organizational unit. It maps to a bounded context in Domain-Driven Design. A context contains type declarations, commands, events, and deciders.

Rules

• <Name> must start with an uppercase letter.
• A .ddd file may contain multiple context blocks.
• Elements within a context can reference each other by name.
• Cross-context references are not yet supported.

Example

ordering.ddd

context Ordering {
  type CartId = String
  type CustomerId = String

  command OpenCart {
    cartId: CartId
    customerId: CustomerId
  }

  event CartOpened {
    cartId: CartId
    customerId: CustomerId
  }

  decider ShoppingCart {
    commands: OpenCart
    events: CartOpened
    state: Empty | Active

    initial: Empty
    terminal: Active

    decide(OpenCart, Empty) -> [CartOpened]
    evolve(Empty, CartOpened) -> Active
  }
}