OpenEuphoria

ensure_in_list

include math.e 
namespace math 
public function ensure_in_list(object item, sequence list, integer default = 1) 

ensures that the item is in a list of values supplied by list.

Parameters:

1. item : The object to test for.
2. list : A sequence of elements that item should be a member of.
3. default : an integer, the index of the list item to return if item is not found. Defaults to 1.

Returns:

An object, if item is not in the list, it returns the list item of index default, otherwise it returns item.

Comments:

If default is set to an invalid index, the first item on the list is returned instead when item is not on the list.

Example 1:

object valid_data = ensure_in_list(user_data, {100, 45, 2, 75, 121}) 
if not equal(valid_data, user_data) then 
    errmsg("Invalid input supplied. Using %d instead.", valid_data) 
end if 
procA(valid_data)