The Text Service Class

The service class Text contains those methods needed to manage ordered sequences of variable length text records, numbered from 1 to n. These are referred to as "text streams". The typical retrieval pattern for text streams is that they are first moved to a certain record in the sequence and then a series of records is accessed from there. The algorithm used is optimal for moving forward through a sequence records once a starting location has been established. As such, the general approach differs from those for "normal" sequences in that the notion of a "current record" or "cursor" is used. The sequence is positioned on a record and that current record can then be manipulated. In addition to optimizing the traversal through the records, the approach also optimizes the storage and changing of records. The individual records are stored in fixed sized blocks in long memory. When a record in inserted into the stream or when the size of a record is changed only the block containing the record needs to be repositioned, not the entire stream. Finally, each text record in the stream consists of two parts: a fixed length component called the "record associated information" followed by the remaining text part, simply called the "record". There is no actual requirement within this class that the records being managed be text records. This class simply maintains them as opaque blocks of bytes with individually specified lengths and associated information. The actual implementation code simply refers to the records being managed as variable length records.

The method Text_Access

Prototype

The Text_Access method Its parameters are:

The method Text_BeforeTop

Prototype

The Text_BeforeTop method Its parameters are:

The method Text_Close

Prototype

The Text_Close method Its parameters are:

The method Text_Create

Prototype

The Text_Create method Its parameters are:

The method Text_Current

Prototype

The Text_Current method Its parameters are:

The method Text_Decrement

Prototype

The Text_Decrement method Its parameters are:

The method Text_Delete

Prototype

The Text_Delete method Its parameters are:

The method Text_Expand

Prototype

The Text_Expand method Its parameters are:

The method Text_GetLocation

Prototype

The Text_GetLocation method Its parameters are:

The method Text_Increment

Prototype

The Text_Increment method Its parameters are:

The method Text_Insert

Prototype

The Text_Insert method Its parameters are:

The method Text_MatchBlocks

Prototype

The Text_MatchBlocks method Its parameters are:

The method Text_Maximum

Prototype

The Text_Maximum method Its parameters are:

The method Text_Open

Prototype

The Text_Open method Its parameters are:

The method Text_Position

Prototype

The Text_Position method Its parameters are:

The method Text_Rewind

Prototype

The Text_Rewind method Its parameters are:

The method Text_SetLocal

Prototype

The Text_SetLocal method Its parameters are: