High-level operations

The following high-level operations are described here after:

FOR: Iterate over all elements of an array or an object.
RETURN: Produce the result of a query.
FILTER: Restrict the results to elements that match arbitrary logical conditions.
SORT: Force a sort of the array of already produced intermediate results.
LIMIT: Reduce the number of elements in the result to at most the specified number, optionally skip elements (pagination).
LET: Assign an arbitrary value to a variable.
COLLECT: Group an array by one or multiple group criteria. Can also count and aggregate.