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| Chapter 5 PL/Vision Package Specifications |

## 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.

### 5.18.1 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.

### 5.18.3 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.

### 5.18.4 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.

5.17 PLVlog: Logging Facility |  | 5.19 PLVmsg: Message Handling

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