Map, filter, reduce

The functions in the Iteration module can be used for functional-style transformation of data structures. Map, for example, takes in a list and a function handler, and applies the function to every item in the list, returning a new list of transformed values. This is a convenient way of performing arbitrary transformations on items in lists.

The Iteration module contains a set of these functions that operate on lists using handler functions that, when chained together, can be used to perform a variety of transformations.

The most important ones are

• Map - used to transform each item into new items
• Filter - used to filter out items in the list that don't pass some criterion
• Reduce - used to reduce a list into a single item, like for example summing up a list of numbers
• Find - used to find a specific item that matches some criterion

Anonymous function handlers

One can assign an anonymous function to the handler property by clicking the f-icon that appears when hovering the property of certain functions, like the ones in the Iteration namespace. Read more about anonymous functions here.