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I've taught a lot of people programming, and frequently work with novices. Functional concepts are nearly universally a sticking point for learners. For loops h

I've taught a lot of people programming, and frequently work with novices. Functional concepts are nearly universally a sticking point for learners. For loops haven't caused any more trouble than the other basic concepts in my experience. It's an order of magnitude more difficult for learners.

civilized 4y ago
Loops are very easy to debug in R. When they break and they're not inside a function, your REPL state is set to exactly what the environment was before the loop broke.
- p10_user 4y ago
  Can’t you do the same thing by dropping a browser() into a function you are applying to each element in a list?
  - civilized 4y ago
    It's not as convenient because now you have to rerun the code and get in and out of a debugging environment (which can be slow). I think FP is good for more concisely expressing simple stuff that's unlikely to break. Don't really believe in using it as a complete replacement for loops.
    - p10_user 4y ago
      How about a conditional breakpoint? Though this doesn’t solve the “issue” of rerunning through the whole list. Or - once you’ve found what element in your list is causing the issue- extract it and feed it to your function with your debugger on. Admittedly I have often had a more challenging time fixing FP code than if I had used a for loop. This might be because I am not as familiar/comfortable with FP than procedural flow. There has to be a for loop eventually. But crawling through a for loop within a procedure can also be painful if there are many different case scenarios. You could counter that good code wouldn’t suffer such a problem, but if the code was good it might not have been broken!
teruakohatu 4y ago
> I've taught a lot of people programming, and frequently work with novices. Functional concepts are nearly universally a sticking point for learners. For loops haven't caused any more trouble than the other basic concepts in my experience. It's an order of magnitude more difficult for learners. The problem is that is teaches people the "wrong" * way to use R. I agree for loops are easier to understand, but when nearly the entire R universe operates on vectors, you end up with students who will do R the hard way their entire career. If you surveyed most R users (verses R programmers) I would say the majority would be unaware that the base type is a vector. * I know there is no wrong way to do anything, but I have seen plenty of times for loops simply applying an already vectorized function to each element of the vector.
- civilized 4y ago
  I think R users should know how to use vectors, vectorized functions, loops, and core tidyverse (e.g. basic dplyr and ggplot). FP stuff like purrr::map isn't essential.

civilized 4y ago

Loops are very easy to debug in R. When they break and they're not inside a function, your REPL state is set to exactly what the environment was before the loop broke.

p10_user 4y ago
Can’t you do the same thing by dropping a browser() into a function you are applying to each element in a list?
- civilized 4y ago
  It's not as convenient because now you have to rerun the code and get in and out of a debugging environment (which can be slow). I think FP is good for more concisely expressing simple stuff that's unlikely to break. Don't really believe in using it as a complete replacement for loops.
  - p10_user 4y ago
    How about a conditional breakpoint? Though this doesn’t solve the “issue” of rerunning through the whole list. Or - once you’ve found what element in your list is causing the issue- extract it and feed it to your function with your debugger on. Admittedly I have often had a more challenging time fixing FP code than if I had used a for loop. This might be because I am not as familiar/comfortable with FP than procedural flow. There has to be a for loop eventually. But crawling through a for loop within a procedure can also be painful if there are many different case scenarios. You could counter that good code wouldn’t suffer such a problem, but if the code was good it might not have been broken!

teruakohatu 4y ago

> I've taught a lot of people programming, and frequently work with novices. Functional concepts are nearly universally a sticking point for learners. For loops haven't caused any more trouble than the other basic concepts in my experience. It's an order of magnitude more difficult for learners. The problem is that is teaches people the "wrong" * way to use R. I agree for loops are easier to understand, but when nearly the entire R universe operates on vectors, you end up with students who will do R the hard way their entire career. If you surveyed most R users (verses R programmers) I would say the majority would be unaware that the base type is a vector. * I know there is no wrong way to do anything, but I have seen plenty of times for loops simply applying an already vectorized function to each element of the vector.

civilized 4y ago
I think R users should know how to use vectors, vectorized functions, loops, and core tidyverse (e.g. basic dplyr and ggplot). FP stuff like purrr::map isn't essential.