You've lost me. Returning an interface isn't returning a concrete thing. It's returning the thing that implements the interface
I'm a very low level functional programmer. I'm big on immutability, big on not using loops and instead using map/flatMap/filter/fold, I tend to roll my own either and option implementations when they don't exist because it's the tidiest way of handling errors I've come across, etc etc. But when it comes to stuff like functors I don't get what it's buying me. What interesting stuff can I do if I know that both an option and a list can be mapped over?
I really need to look more deeply into it at some stage. I might be missing out on some powerful tools. Or it might be a bunch of stuff that's theoretically interesting but practically useless.
I'm a very low level functional programmer. I'm big on immutability, big on not using loops and instead using map/flatMap/filter/fold, I tend to roll my own either and option implementations when they don't exist because it's the tidiest way of handling errors I've come across, etc etc. But when it comes to stuff like functors I don't get what it's buying me. What interesting stuff can I do if I know that both an option and a list can be mapped over?
I really need to look more deeply into it at some stage. I might be missing out on some powerful tools. Or it might be a bunch of stuff that's theoretically interesting but practically useless.