Ocaml list.map error this function is applied to too many arguments

Question

Hello I am new to Ocaml and I am trying to play around with List and list.map. So I write a function helper which takes a list and creates a list of lists.

let rec helper l= 
  match l with 
  | []->[[]]
  | x::xs -> [x]::helper xs;;

Now when i try to use list.map to concatenate to each member of this list of list i get an error.

List.map(fun y->[1]@y) helper [1;2;3];;

Error: This function is applied to too many arguments; maybe you forgot a;'`

I am unable to understand why is this error causes. Any help would be appreciated.

Thank you

Jackson Tale Jackson Tale · Accepted Answer · 2014-02-05T16:48:38

You need () for helper [1;2;3]

i.e., List.map(fun y->[1]@y) (helper [1;2;3]).

This will remove the error.

Ocaml list.map error this function is applied to too many arguments

1 Answers