home | O'Reilly's CD bookshelfs | FreeBSD | Linux | Cisco | Cisco Exam    

5.24 PLVstk: Stack Manager

The PLVstk (PL/Vision STacK manager) package is a generic manager for both first-in-first-out ( FIFO ) and last-in-last-out ( LIFO ) stacks; it is built on PLVlst. See the companion disk for details.

5.24.1 Package constants

defstk CONSTANT VARCHAR2(5) := 'stack';

The name of the default stack.

lifo CONSTANT VARCHAR2(4) := 'LIFO';

Indicates that you are working with a last-in-first-out stack. Used in calls to pop .

fifo CONSTANT VARCHAR2(4) := 'FIFO';

Indicates that you are working with a first-in-first-out stack. Used in calls to pop .

5.24.2 Creating and destroying stacks

PROCEDURE make
(stack_in IN VARCHAR2 := defstk,
overwrite_in IN BOOLEAN := TRUE);

Allocates storage for a stack of up to 1,000 items with the specified name. By default, if the stack already exists it will be reinitialized to an empty stack.

PROCEDURE destroy (stack_in IN VARCHAR2 := defstk);

Releases all memory associated with this stack.

5.24.3 Modifying stack contents

PROCEDURE push
(item_in IN VARCHAR2, stack_in IN VARCHAR2 := defstk);

Pushes an item onto the specified stack.

PROCEDURE pop
(value_out IN OUT VARCHAR2,
stack_in IN VARCHAR2 := defstk,
stack_type_in IN VARCHAR2 := lifo);

Pops an item off the top ( LIFO ) or bottom ( FIFO ) of the stack.

5.24.4 Analyzing stack contents

FUNCTION nitems (stack_in IN VARCHAR2 := defstk)
RETURN INTEGER;

Returns the number of items currently in the stack.

FUNCTION itemin (stack_in IN VARCHAR2, item_in IN VARCHAR2)
RETURN BOOLEAN;

Returns TRUE if the specified item is found in the stack.

5.24.5 Tracing Stack Activity

PROCEDURE show
(stack_in IN VARCHAR2 := defstk,
show_contents_in IN BOOLEAN := FALSE);

Requests that pre-action status of stack be displayed for the specified stack (or all).

PROCEDURE noshow;

Turns off display of pre-action status.

FUNCTION showing RETURN BOOLEAN;

Returns TRUE if showing pre-action status.

PROCEDURE verify
(stack_in IN VARCHAR2 := defstk,
show_contents_in IN BOOLEAN := FALSE);

Requests that post-action status of stack be displayed for the specified stack (or all).

PROCEDURE noverify;

Turns off display of post-action status.

FUNCTION verifying RETURN BOOLEAN;

Returns TRUE if showing post-action status.


Previous: 5.23 PLVrb: Rollback Processing Advanced Oracle PL/SQL Programming with Packages Next: 5.25 PLVtab: Table Interface
5.23 PLVrb: Rollback Processing Book Index 5.25 PLVtab: Table Interface

The Oracle Library Navigation

Copyright (c) 2000 O'Reilly & Associates. All rights reserved.

Library Home Oracle PL/SQL Programming, 2nd. Ed. Guide to Oracle 8i Features Oracle Built-in Packages Advanced PL/SQL Programming with Packages Oracle Web Applications Oracle PL/SQL Language Pocket Reference Oracle PL/SQL Built-ins Pocket Reference










??????????????@Mail.ru