Class %Collection.AbstractList

abstract class %Collection.AbstractList extends %Collection.AbstractIterator

A list collection represents a list of data type elements, each of which is associated with a numeric position in the list. The first element in the list is stored at position 1.

The %Collection.AbstractList class provides the basic functionality of the various list collection classes.

The non-abstract list classes derived from %AbstractList include %ListOfDataTypes, %ListOfObjects, %Collection.ListOfObjects and %Collection.ListOfDT. You can use a list object as follows:

	Set list=##class(%ListOfDataTypes).%New()
	; add items to the list
	Do list.Insert("Harpo")
	Do list.Insert("Groucho")
	Do list.Insert("Chico")
	Do list.Insert("Karl")
	; iterate over contents of list
	For i=1:1:list.Count()  Write list.GetAt(i),!

Inventory

Parameters	Properties	Methods	Queries	Indices	ForeignKeys	Triggers
		14

Summary

Methods
Clear	Count	Find	GetAt	GetNext
GetPrevious	Insert	InsertAt	InsertList	InsertOrdered
Next	Previous	RemoveAt	SetAt

Subclasses
%Collection.AbstractListOfDT	%Collection.AbstractListOfObj	%Library.AbstractList

Methods

• abstract method Clear() as %Status

Clears the contents of the list.
Returns a %Status value indicating success or failure.

• abstract method Count() as %Integer

Returns the number of elements contained in the list.

• abstract method Find(element As %CacheString, key As %Integer) as %String

Starting from, but not including, position key, Find finds the next element in the list with value equal to element. If key is a null string, Find starts at the beginning of the list.
Find returns the position of the found element or null string ("") if no element was found.

• abstract method GetAt(key As %Integer = 0) as %CacheString

Finds and returns the value of the element at position key in the list.
GetAt returns the value of the element at location key or null string ("") if no element is found.

• abstract method GetNext(ByRef key As %Integer) as %CacheString

Finds and returns the value of the element at the position after key in the list. If key is a null string (""), it returns the value of the first element in the list.
The value of key, which is passed by reference, is updated to the position value of the returned element or null string ("") if key is at the end of the list.

• abstract method GetPrevious(ByRef key As %Integer) as %CacheString

Finds and returns the value of the element at the position before key in the list. If key is a null string (""), it returns the value of the last element in the list.
The value of key, which is passed by reference, is updated to the position value of the returned element or null string ("") if key is at the beginning of the list.

• abstract method Insert(element As %CacheString) as %Status

Inserts an element with value element at the end of the list.
Returns a %Status value indicating success or failure.

• abstract method InsertAt(element As %CacheString, key As %Integer) as %Status

Inserts an element with value element at position key.
To make room for the new element, the elements previously at or following position key are moved up by one position.
key must be in the following range:
1 <= key <= Count() + 1
Returns a %Status value indicating success or failure.

• abstract method InsertList(inslist As %CacheString) as %Status

Inserts a list with value inslist at the end of the list.
Returns a %Status value indicating success or failure.

• abstract method InsertOrdered(element As %CacheString) as %Status

Inserts an element with value element into the list at the correct ordered position. The elements in the list are shifted to accommodate the new element as necessary.
Returns a %Status value indicating success or failure.

• abstract method Next(key As %Integer = 0) as %Integer

Finds and returns the index value of the element at the location following key in the list. If key is a null string (""), then Next returns the position of the first element in the list (1).

• abstract method Previous(key As %Integer = 0) as %Integer

Finds and returns the index value of the element at the location preceding key in the list. If key is a null string (""), then Next returns the position of the last element in the list.

• abstract method RemoveAt(key As %Integer) as %CacheString

Removes the element at position key in the list. The elements following position key are moved to fill in the resulting gap.
RemoveAt returns the value of the removed element or null string ("") if no element was removed.

• abstract method SetAt(element As %CacheString, key As %Integer) as %Status

Sets the value of the element at position key to element.
Returns a %Status value indicating success or failure.


[BASEXML] > [%Collection] > [AbstractList]		Private Storage