remove last element of a list sml by keeping the list in a val

How can I remove the last element in a list in Standard ML? I have a list defined as:

val list = [1, 4, 6, 8, 9]

and I want to remove the last element and have the list in the val list.

Solution

Well you have various ways of doing it.

You could take the original list apart, and start building a new list with the elements, until you reach the last element.
```
fun f [] = ...
  | f [x] = ...
  | f (x::xs) = x :: ...
```
Or you could use the List.take function to take the first i elements from the list. Obviously you could use the List.length function to calculate how many elements you wan't to take from the list.
```
fun h xs = List.take (xs, ...)
```