The IntList class describes immutable linked lists of integers. An integer list is either the empty list or a (non-empty) list node with a head component that is an integer and a tail component that is another integer list. The lists are immutable in the sense that the head or tail of a list node cannot be changed after the list node has been created (via the prepend() method).
There are no public constructor or instance methods for integer lists; they are created and manipulated by the following class methods:
Class Methods
public static IntList
empty()
Returns an empty integer list.
public static IntList
prepend (int n, IntList
L)
Returns a new integer list node whose head is n and whose tail is L.
public static
boolean isEmpty
(IntList L)
Returns true if
L is an empty integer list and
false if L is an integer list node.
public static
int head (IntList
L)
Returns the integer that is the head component of the integer
list node L. Signals an exception
if L is empty.
public static IntList tail
(IntList L)
Returns the integer list that is the tail component of the
integer list node L. Signals an
exception if L is empty.