5.18 PLVlst: List Manager

The PLVlst (PL/Vision LiST manager) package provides a generic list manager for PL/SQL built on PL/SQL tables. See the companion disk for details.

Package exceptions

• list_undefined EXCEPTION;
• Raised when you attempt to perform a PLVlst operation on an undefined list.
• list_full EXCEPTION;
• Raised when you attempt to add another item to a list which is already full (currently limited to maximum of 10,000 items in a list).
• out_of_bounds EXCEPTION;
• Exception raised when you try to reference an item in the list that is not defined.

5.18.2 Creating and destroying lists

• PROCEDURE make (list_in IN VARCHAR2);
• Allocates storage for a new list of the specified name.
• FUNCTION is_made (list_in IN VARCHAR2) RETURN BOOLEAN;
• Returns TRUE if the specified list already exists.
• PROCEDURE destroy (list_in IN VARCHAR2);
• Destroys the list, freeing up associated memory.

Modifying list contents

• PROCEDURE appenditem (list_in IN VARCHAR2, item_in IN VARCHAR2);
• Adds an item to the end of the specified list.
• PROCEDURE insertitem
• (list_in IN VARCHAR2, position_in IN NUMBER,
• item_in IN VARCHAR2);
• Inserts an item at the specified position in the list.
• PROCEDURE prependitem (list_in IN VARCHAR2, item_in IN VARCHAR2);
• Inserts an item at the first position of the list.
• PROCEDURE replaceitem
• (list_in IN VARCHAR2, position_in IN NUMBER,
• item_in IN VARCHAR2);
• Replaces the nth item in the list with the new item.
• PROCEDURE deleteitem (list_in IN VARCHAR2, item_in IN VARCHAR2);
• Deletes the first occurrence of the specified item from the list.
• PROCEDURE deleteitem (list_in IN VARCHAR2, position_in IN NUMBER);
• Deletes the item at the specified location in the list.

Analyzing list contents

• FUNCTION getitem (list_in IN VARCHAR2, position_in IN NUMBER);
• Returns the nth item from the list.
• FUNCTION getposition (list_in IN VARCHAR2, item_in IN VARCHAR2)
• RETURN NUMBER;
• Returns the position of the specified item in the list.
• FUNCTION nitems (list_in IN VARCHAR2) RETURN INTEGER;
• Returns the number of items currently in the list.
• PROCEDURE display (list_in IN VARCHAR2);
• Displays the contents of the specified list.