Lists

Lists are represented with [], and can span multiple lines. A final trailing comma is optional.

from numbers
derive [x = 1, y = 2]
derive [
  a = x,
  b = y
]
derive [
  c = a,
  d = b,
]

SELECT
  *,
  1 AS x,
  2 AS y,
  1 AS a,
  2 AS b,
  1 AS c,
  2 AS d
FROM
  numbers

Most transforms can take either a list or a single item, so these are equivalent:

from employees
select [first_name]

SELECT
  first_name
FROM
  employees

from employees
select first_name

SELECT
  first_name
FROM
  employees