Non Terminal Atom Production

The other atoms - sets, bags, arrays, lists and structs - are non terminal atoms. This means that they cannot be generated using a simple lexical construct.

List, Set, Bag and Array Atoms

To construct a collection atom - list, set, bag or array -, one may use the function collection() where collection denotes the collection type, for instance:

set(1, 2, 3)
list(1, "hello", "world")
array(2, 3, list(3893, -2, 'a'), 22)
bag(2, 2, 3, 4, 5, 12)

This is the simple way to construct such atoms, but as any other atoms, a collection atom may be produced by the OQL interpreter as the evaluation of a complex expression, for instance:

select x from Person x

produces an atom bag of objects.

Struct Atom

The most direct way to construct a struct atom is as follows:
struct({identifier:expr})

For instance:

struct(a: 1)
struct(format: text, s: "this is the text")
struct(name: "john", age: 32, spouse: first(select Person))