Let's start with an example. The problem at hand now is that we want to process a large list of records and get some metrics and indicators over them. Given a large data set with information about purchases, we want to process it in order to get the lowest sale, highest sale, and the average price of a sale.
For the simplicity of this example, we will assume a CSV with only two fields, in the following format:
<purchase_date>, <price>...
We are going to create an object that receives all the purchases, and this will give us the necessary metrics. We could get some of these values out of the box by simply using the min() and max() built-in functions, but that would require iterating all of the purchases more than ...
