I forgot the 3rd category, those who see the world exclusively through the functional programmer lens :-D Mapping functionally it worth it if the transformatio

I forgot the 3rd category, those who see the world exclusively through the functional programmer lens :-D Mapping functionally it worth it if the transformation between A and B is regular enough. But things are dirty. Some irregularities appear and now the perfect higher-order function doesn't work nicely anymore. With the imperative approach it just means adding 1 -3 more lines.