Share 'Sorting using Keys & Values (aka Synchronous Sorting)'

Sorting data is a common task in programming. Unfortunately only numbers and text have a well-defined sorting behaviour, and even text can be pretty ambiguous depending on the language it is in and the local culture setting of the system. Other types of data -say colours- do not have an obviously correct way to sort them. Should colours be sorted by brightness, or amount of red, or hue, or satu…