Question

I have a list like:


[[1,2,3,4,5],[6,7,8,9]]


I’m trying to do it using list comprehension and have got as far as:

each_in_lists x = [show y | y <- x]

where x is the list of lists.

Answer 1

Are you trying to convert it to string

> let x = [[1,2,3,4,5],[6,7,8,9]] 
> [show a | y <- x, a <- y]
["1","2","3","4","5","6","7","8","9"] 

If you are trying to print, use print. print uses the show instance of the elements to convert it to string and then uses putStrLn.

> mapM_ (mapM_ print) x                          
1                                                                                   
2                                                                                   
3                                                                                   
4                                                                                   
5                                                                                   
6                                                                                   
7                                                                                   
8                                                                                   
9