Programming Groovy 2

19.7 Closures and DSLs

The ​with​ method helps delegate calls within a closure, giving us an execution context. We can take advantage of this approach to create our own methods with context and fluency.

Let’s revisit the pizza-ordering example. Say we want to create a syntax that flows naturally. We don’t want to create an instance of ​PizzaShop​ because that is more of an implementation detail. We want the context to be implicit. Let’s look at the following code (in the next section we’ll see how to make this more fluent and context-driven):

time = getPizza {
  setSize Size.LARGE
  setCrust Crust.THIN
  setTopping "Olives", "Onions", "Bell Pepper"
  setAddress "101 Main St., ..."
 setCard(CardType.VISA, ...