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0 pointsahoka9y ago0 comments

Map, filter, fold, etc. are pretty much standard constructs and any decent programmer should be familiar with them.

There are subtle variations in naming like Java's Map is Select in C# because Microsoft modeled its functional API on SQL, but you have the same differences for iteration and selection (the things you are referring to for and if).

For example you have 'for (int i = 0; i < n; i++)' in C, but you don't have the exact same way of doing it in Python, where you have to use a range: 'for num in range(0, n):' or you can write a 'while' loop in Java but not in Go where it's a 'for' with a single expression.

I would choose a functional version over a three level nested for loop monster any day.

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reitanqild9y ago

Let me be the one:

I'm a fairly decent programmer and I never worked with map or flatmaps outside of examples.

I have however significantly simplified two significant code bases, made and maintained for years a webapp that users loved etc.

Very often I feel it is just people wanting to sell something and it wouldn't surprise me if many of the people who sell functional are the same who sold object oriented back in the day.

This article was actually a bit refreshing IMO.

kaeluka9y ago

As programmers, we often confuse the means with the ends. We tend to over-emphasise the way in which code is written and we tend to forget about whether the code is doing the right thing.

That being said, I love map/filter/flatMap. Look at them as higher level loops.

For example: A while loop is very general, you can implement any kind of loop with it. This makes it harder to understand the meaning of the loop. Therefore, when you want to iterate a constant number of times, you'll likely use a for loop. It expresses your intent better. Map, filter, and flatMap are just extending this principle to more specialised use cases. The advantage for a reader is that the one word "map" already tells them a lot about what the loop body is good for.

kochthesecond9y ago

This is the way I see it. A for loop is good if I'm counting, if I'm applying a function to every element in a list, I should express that.

An added bonus is that null elements are sorted and that you HAVE to separate data manipulation operations. You have to filter, map and apply sorting separately, not mix all three in a triple for loop with several branches.

heisenbit9y ago

Maybe it is a higher level of looping and certainly looks pleasing. However when it comes to using a debugger I have not found a way to avoid a higher level of effort.

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