key

key

In Wasp, a key is a node with another node as its value.

a:1
b:"Hello"
c:fibonacci
d:fibonacci(10)
e: x+1
person:{name:James, age:45}

The person example shows how key value pairs form natural nested data: maps and trees.

The difference to person{name:James, age:45} is, that here person contains name:James and age:45 as children. In person:{name:James, age:45} person contains {name:James, age:45} as value. {name:James, age:45} itself is an unnamed object with children name:James and age:45.

Internally these slightly different representations may be normed and flattened at times.

Semantically person:{name:James, age:45} is passive data whereas person{name:James, age:45} denotes an active constructor of person if available, otherwise passive data too.

complex keys

In Wasp, keys need not be primitive values, but can be complex objects: (a b c):(d e f)

This is represented internally by having the left side as children and the right side as value ⚠️ In complex keys, children represent the key object, not the value!

empty values

The value of a key can never be null, but it can unknown: Either as a reference to a node of type unknown, or by pointing to null. Such keys can still have a type.

Unlike other languages, a key in Wasp contains it's value itself.

In Wasp, a key is a node of internal kind Type::key.