Why do functional programmers hate looping constructs of imperative languages and ignore them as if they don't exist?
Ask HN: Why do functional programmers hate loops (for, while, etc.)?
1–10 of 73 posts
Re: Ask HN: Why do functional programmers hate loops (for, while, etc.)?
#2Have you used tail|head in any language. To them it seems more elegant and a "better" way of doing things.
Re: Ask HN: Why do functional programmers hate loops (for, while, etc.)?
#3I guess looping constructs have some kind of states and functional paradigm, as I understand it, avoids them.
Re: Ask HN: Why do functional programmers hate loops (for, while, etc.)?
#4To some extent for while loops are a matter of taste. But the issue is that unless you have mutable variables, you cannot use typical imperative control variables.
So something like:
bool done = false;
while (!done) {
...
}
Re: Ask HN: Why do functional programmers hate loops (for, while, etc.)?
#5functional programmers are kind of like cargo bike riders. they know they can solve their problem otherwise and in a much simpler fashion but insist on riding the cargo bike.
Re: Ask HN: Why do functional programmers hate loops (for, while, etc.)?
#6Well, how to calculate sum from 1 to 5000 ?
Instead of looping from 1 to 5000, you define the relationship instead:
sum(1,n) = 1 + n + sum(2, n-1).
Isn't this clearer to understand problem first, instead of just looping ?
Re: Ask HN: Why do functional programmers hate loops (for, while, etc.)?
#7For some people, thinking in "functions" makes more sense than thinking in "algorithms".
The former prefers a "declaration" of THE state. for/while loops imply a change of state, so they're a big no here.
The latter prefers an "imperative set of steps" to go from initial state to the desired state. for/while loops make the "steps" easier here.
Re: Ask HN: Why do functional programmers hate loops (for, while, etc.)?
#8Well, how to calculate sum from 1 to 5000 ? Instead of looping from 1 to 5000, you define the relationship instead: sum(1,n) = 1 + n + sum(2, n-1). Isn't this clearer to understand problem first, instead of just looping ?
No, it isn't clearer. Just different. Which one is clearer depends who is reading and the way they think.
Re: Ask HN: Why do functional programmers hate loops (for, while, etc.)?
#9[deleted]
Re: Ask HN: Why do functional programmers hate loops (for, while, etc.)?
#10Be very careful with "why do X hate Y?" Generally speaking, if someone comes out as outright hating Y, their opinion should be taken with a pound of salt.
Functional programming is fundamentally at odds with imperative constructs. It's not that people hate them, it's that they generally just don't fit the paradigm of "build a pipeline of steps (functions) and feed data into it" as well. Most of my software is functional, but you will find the occasional C-style loop, especially if the map/filter/reduce alternative is ridiculously complicated to read.