TStringClass - large string management for DELPHI

The 'TStringClass' class is designed to manage large string variables by encapsulating a core PChar type text buffer within a controlled class wrapper. Standard Object Pascal 'STRING' type text variables are easy to use and manipulate, but suffer from a having a maximum size of 255 characters. If you are processing large arrays of STRING type variables they can waste valuable stack or heap space. The alternative to using STRING types is to use the null terminated string (or 'PChar') type. For most programmers PChar's are a necessary evil. This 'TStringClass' object was originally developed to solve some of the problems that are frequently encountered whilst using 'PChar' type variables, namely:

• Using un-intialised or 'NIL' PChar variables with any of the STRINGS unit functions.
• Not declaring buffers of sufficient length, such that concatenating variables leads to internal memory overwrites

The TStringClass object offers solutions to these and other related problems. It controls its own internal buffer for holding the PChar variable, and before performing any assignments or concatenations it always checks to see that sufficient room is available. If there is insufficient space it re-sizes the buffer to fit the required action. This object was originally created to counteract problems with 'guess-timating' the PChar variable buffer length for complicated SQL expressions. Since then it has been expanded to cover almost anything that can be done with a string type variable, with 190+ methods now available, including:

• Multiple constructors for initiating the object for different situations
• A set of high level methods for working with other TStringClass type variables
• A range of different 'Assign' methods for moving different types of text variables into the object data value.
• A range of different 'Append' methods for adding different types of text variables onto the end of any existing object data value
• A set of character level methods for testing the object data string
• A set of methods associated with converting other numeric data types into strings, or vice-versa
• A set of methods that mimic the functions found in the STRINGS unit
• A set of methods that mimic the text related functions found in the 'SysUtils' unit
• Methods for string resource and INI file access
• A set of methods for inserting, deleting, padding and trimming the object's data string
• A set of methods to manage comparisons with another PChar variable
• A set of methods to provide DOS/Path name related processing and testing
• Methods for searching characters and sub strings, including grep
• Methods for changing case
• Methods for replacing characters or sub strings.
• Methods for parsing the object's data string

As a rule the object is designed to handle the problems of passing NIL or zero length PChar parameters. It can also manage the thorny old problem of passing parameters which are un-initialised or remain in use after they have been disposed. These are captured by exception handling.

The product is supplied with a detailed manual in both Word For Windows and HLP format. It includes a test bed application that illustrates the use of of the main methods.

TStringClass is a shareware product. It is fully functional, and includes DCU files for both DELPHI 1 and DELPHI 2. To obtain the source code you must register your use of the product. For further information select the 'Order' option shown below

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