Lists are used to represent groups of objects. Like objects, they have vars and procs associated with them. In order to access these attributes, list vars must be declared of type /list. These may then be assigned to existing lists, or used to create new lists.
var/list/L // list reference
L = world.contents // assign to existing list
L = new/list() // make a new list
L = new() // make a new list (implicit type)
L.Add("futz") // L contains: "futz"
del(L) // delete LLists created with ‘new()’ have a default length of 0; this can be overridden by specifying the size; that is, new/list(size) creates a list with size (null) elements.
The ‘list()’ proc may be used to more easily initialize list data.
var/list/L
L = list("futz",3) // L contains: ("futz", 3)Alternatively, lists may be declared by using brackets, ’[]‘. Empty brackets indicate a list reference, exactly as /list does, so list/L is equivalent to L[]. Setting an initial size within the brackets, for instance, L[10], creates a list of that initial size.
var/L[] // same as var/list/L: list reference
var/M[10] // initially empty list of size 10
L = M // L is now an empty list of size 10Once a list L is declared, a specific item can be accessed by putting its index in the brackets: L[index].
Indices range from 1 to len. If the length of the list is changed, existing elements in the list will be preserved if they are less than the new length. New elements in the list will be given the initial value of null.
var/L[5] // initial length of 5
var/i
for(i=1, i<=L.len, i++)
L[i] = i
// L contains: (1,2,3,4,5)
L.len = 7 // expand list
// L contains: (1,2,3,4,5,null,null)
del(L) // destroy listMulti-dimensional lists may be created by making a list of lists.
var/grid[10][5]
grid[1][1] = 1
grid[1][2] = 2
...Such a list may also be created by using new(). As in the previous example, the next one creates a list of 10 lists each having 5 elements.
var/grid = new/list(10,5)