components.linkedlist

Interface LinkedListKernel<T>

Type Parameters:

T -

All Superinterfaces:

Standard<LinkedList<T>>

All Known Subinterfaces:

LinkedList<T>

All Known Implementing Classes:

DoublyLinkedList, LinkedList1L, LinkedListSecondary, SinglyLinkedList

public interface LinkedListKernel<T>
extends Standard<LinkedList<T>>

LinkedList kernel component containing method headers and contracts for all methods that will directly interact with the label representations of all LinkedList implementations. All sub-interface methods should use only these methods to perform operations on the LinkedList.

Author:

Matthew Shoemaker

Method Summary

Modifier and Type	Method and Description
void	add(T entry) Appends entry to the end of #this.
void	addToFront(T entry) Adds entry to the front of #this.
void	advance() Shifts #this.focus forward by 1 position.
T	focus() Returns a reference to #this.focus.
void	insert(T entry) Inserts entry into #this at the position directly following the #this.focus.
int	length() Returns the number of entries in this.
void	moveToFront() Shifts this.focus to the front of the list.
void	moveToRear() Moves #this.focus to the last entry in this.
int	position() Returns the position of #this.focus.
T	remove() Removes this.focus and returns it to the caller.
void	retreat() Shifts this.focus to the entry previous to #this.focus.

Methods inherited from interface components.standard.Standard

clear, newInstance, transferFrom

Method Detail

add

void add(T entry)

Appends entry to the end of #this.

Parameters:

entry - item to be appended to this

Updates:

this

Requires:

entry != null

Ensures:

this = #this * entry

addToFront

void addToFront(T entry)

Adds entry to the front of #this.

Parameters:

entry - item to be prepended to this

Updates:

this

Requires:

this.length > 0

Ensures:

this = entry * #this

remove

T remove()

Removes this.focus and returns it to the caller. this.focus will be shifted to the right, and if #this.focus was the last entry, then this.focus shifts to the first entry in #this.

Returns:

#this.focus

Updates:

this

Requires:

#this.length > 0

Ensures:

          remove = [#this.focus] and
          [if #this.focus is the final entry in
          the list, this.focus will be the first entry in the array]
          

advance

void advance()

Shifts #this.focus forward by 1 position.

Requires:

#this.position < #this.length

Ensures:

this.position = #this.position + 1

retreat

void retreat()

Shifts this.focus to the entry previous to #this.focus.

Requires:

#this.position > 0

Ensures:

this.position = #this.position - 1

moveToFront

void moveToFront()

Shifts this.focus to the front of the list.

Ensures:

this.focus is the first entry of the list

length

int length()

Returns the number of entries in this.

Returns:

the number of entry of this

Ensures:

length = |this|

insert

void insert(T entry)

Inserts entry into #this at the position directly following the #this.focus.

Parameters:

entry - entry to be inserted into the list

Updates:

this

Ensures:

          this = [(entries before #this.focus) * #this.focus * entry *
          (entries after #this.focus)] and
          [this.focus = #this.focus]
  

focus

T focus()

Returns a reference to #this.focus.

Returns:

#this.focus

Requires:

this.length > 0

Ensures:

this = #this and focus = #this.focus

moveToRear

void moveToRear()

Moves #this.focus to the last entry in this.

Requires:

this.length > 0

Ensures:

this.focus = final entry in this

position

int position()

Returns the position of #this.focus.

Returns:

the distance of this.focus fron the front of the list

Ensures:

          if
              this.length == 0, then position = -1
          else
              position = [the distance of the focus from the first entry in
          the list]