Generator Operator

A Generator operator produces a result set without input.

Like an Iterator, a Generator lets you specify JavaScript expressions for initializing variables, updating variables, and testing for termination. Unlike an Iterator, a Generator does not accept inputs. Like a Projection operator, a Generator allows you to specify the names and types of the output columns, as well as JavaScript expressions for computing the values in each row.

When a Generator is first called, it executes the Initialize expression you supply to initialize variables. On each call, Generator follows this sequence:

Tests the termination condition.
If the termination condition has not been met, it generates a row with the designated schema by executing all of the user-specified JavaScript expressions.
Executes the Increment expression you supply to update variables.

The output of the Generator is the sequence of rows created in these iterations.