FT Toolkit Overview

NANFOR.LIB Working Group G. Scott [71620,1521]
Overview UCLA
Version 2.1 October, 1992

THE NANFORUM TOOLKIT (NANFOR.LIB)
PUBLIC DOMAIN USER SUPPORTED CLIPPER FUNCTION LIBRARY

.

1 INTRODUCTION

This is a standard for establishing and maintaining NANFOR.LIB, a public-domain, user-supported library of functions designed to interface with Computer Associates CA-Clipper, version 5.01a, and later. You are encouraged to read it over and forward comments to Glenn Scott, CIS ID [71620,1521].

1.1 History

In October and November of 1990, a discussion on the evolution of third-party products, vendors, and marketing took place on the CompuServe Information Service’s Nantucket Forum (NANFORUM). During this discussion, a forum subscriber named Alexander Santic suggested the idea of a user-supported Clipper function library, available to all on the CompuServe Information Service (CIS). A number of subscribers, including several Clipper third party developers, and some Nantucket employees, expressed their support. This standard was a first step toward organizing such an endeavor.

Release 1.0 of the toolkit was made available in April, 1991 and had nearly 150 functions. By the time version 2.0 was released in August, 1991, the 1.0 library had been downloaded nearly 700 times by CompuServe users. By October of 1992, release 2.0 had been downloaded over 2100 times. The source code had been downloaded nearly 1500 times. In addition, release 2.0 was placed on the massive Internet archive site called SIMTEL20 where it was downloaded by CA- Clipper users worldwide. Over the course of the year that release 2.0 was available, seven patches were issued, each one gathering nearly 1000 downloads.

Computer Associates International, Inc. acquired Nantucket in the summer of 1992 and subsequently renamed NANFORUM to simply CLIPPER. In addition, the Clipper product itself was renamed to CA-CLIPPER. Despite the name changes, forum members decided to keep the toolkit’s name as “The Nanforum Toolkit,” partly for nostalgia. References to NANFORUM in this RFC have been replaced with CLIPPER.

1.2 Trademarks

CA-Clipper is a registered trademark of Computer Associates International, Inc. Computer Associates will be referred to as CA throughout this document.

1.3 Relationship to CA and third party

NANFOR.LIB is a project independent of any third party developer or CA. There is no official “sanction” or “seal of approval” from CA of any kind. In addition, NANFOR.LIB routines will be accepted and included without regard for whether or not routines performing a similar function are included in a commercial third party or CA product.

It is desired that NANFOR.LIB not compete with third party products but rather fill in the holes in CA-Clipper’s standard library. However, there will be some overlap into commercial third-party library functions, so it would be best if this is never taken into consideration when deciding on including a particular function.

Developers submitting NANFOR.LIB routines can and will be corporate developers, third party developers, independent consultant / programmers, hobbyists, and other CA-Clipper people. Perhaps even CA employees will contribute. No one is excluded or included due to any particular affiliation.

CA employees submitting functions are doing so as individuals, and are not making a policy of involving CA in the project, nor are they committing CA to supporting the public domain library.

1.4 CA-Clipper version supported

NANFOR.LIB functions, no matter what language they are written in, will be designed to work with CA-Clipper version 5.01a and later. Many of the functions, particularly those that use the EXTEND system, will be compatible with the Summer 1987 version of CA-Clipper. However, ensuring Summer 87 compatibility will be the responsibility of the user. If a user wants a function to work with Summer 87, she will have to modify the code herself if necessary. In many cases, this is a trivial task.

1.5 Queries from new users

Queries from new users interested in finding NANFOR.LIB should be handled in a uniform and courteous way. A short text file will be created that will briefly explain NANFOR.LIB, who the current people maintaining it are, and how to get a hold of it. This text message can be sent in response to any query. TAPCIS users will find this method very easy to implement.

2 DISTRIBUTION

2.1 Public Domain

NANFOR.LIB, its source code, and documentation will be public-domain software. It is not for “sale”, and shall not be sold. No fee or contribution of any kind will be required for anyone wanting a copy, other than what they would normally pay to download it from CompuServe. Users will be encouraged to submit functions via CompuServe.

2.2 Official repository

It is possible that copies of NANFOR.LIB will be downloaded and distributed elsewhere. This is encouraged, but the only copy of NANFOR.LIB and all associated documentation that will be maintained by volunteers is in an appropriate library on the CIS CLIPPER Forum.

2.2.1 Contents

The deliverables that make up the official posting on CompuServe shall be:

2.2.1.1 NFLIB.ZIP

This will contain the files NANFOR.LIB (library), and NANFOR.NG (Norton Guide).

2.2.1.2 NFSRC.ZIP

This will contain all the library source code, makefile, and other source-code related materials.

2.2.1.3 NFINQ.TXT

This is a short text file used as a response to new user queries (see paragraph 1.5)

2.2.1.4 NFRFC.ZIP

This contains an ASCII format, as well as a WordPerfect 5.1 format copy of NANFOR.RFC named NFRFC.TXT (ASCII) and NFRFC.WP5 (WordPerfect 5.1).

2.2.1.5 NFHDRS.ZIP

This contains templates of the file and documentation header blocks, including a sample, for prospective authors (FTHDR.PRG, FTHDR.ASM, FTHDR.SAM)

2.2.1.6 PATx.ZIP

These are patch files (see paragraph 4.5.1).

3 POLICY ON INCLUDING FUNCTIONS

3.1 “Best Function”

It is possible that more than one developer will submit a function or package of functions that perform substantially the same services. In that event, the referees will choose one to be included based on power, functionality, flexibility, and ease of use. Due to the cooperative, non-commercial nature of the library, no one’s feelings should be hurt by excluding duplicate functions.

In addition, it is possible that two substantially similar functions or packages will benefit from merging them together to provide new functionality. This will be the prerogative of the referees (see paragraph 6.3), in close consultation with the authors.

3.2 Public Domain

Each author submitting source code must include as part of that code a statement that this is an original work and that he or she is placing the code into the public domain. The librarian (see paragraph 6.1) and referees should make a reasonable effort to be sure no copyrighted source code, such as that supplied with some third party libraries, makes it into NANFOR.LIB. However, under no circumstances will the librarian, referees, or any other party other than the submitter be responsible for copyrighted code making it into the library accidentally.

3.3 Source code

Full source code must be provided by the author for every routine to be included in NANFOR.LIB. No routine, no matter what language, will be put into the library on the basis of submitted object code.

3.4 Proper submission

Due to the volume of submissions expected, librarians and referees may not have the time to fix inconsistencies in documentation format, function naming, and other requirements. Therefore, the librarian shall expect source code to arrive in proper format before proceeding further with it.

3.5 Quality and perceived usefulness

In a cooperative effort like this, it is very difficult to enforce some standard of quality and/or usefulness. For example, a package of functions to handle the military’s “Zulu time” may be very useful to some, and unnecessary to others.

The Nanforum Toolkit will by its very nature be a hodgepodge of routines, some of very high quality, some not so high. It is up to the users to improve it. It will be complete in some areas and vastly inadequate in others. It is up to the users to fill in the holes.

We shall err on the side of including “questionable” functions, provided they seem to work. Debates on the quality of the library’s source code shall be encouraged and will take place in the proper message section of the CompuServe CLIPPER forum.

4 LIBRARY MAINTENANCE PROCEDURE

4.1 Selection procedure

Source code will be submitted to the librarian, the documenter (see paragraph 6.2), or one of the referees. Code will be added if it has been reviewed, and approved by at least one, but preferably two, referees.

Code not meeting the documentation or source code formatting standards will generally be returned to the author with instructions.

Referees will test the submitted code. When the referees have finished evaluating a submission, they will report their approval or disapproval to the librarian, with comments.

Every effort should be made to make sure that the C and ASM functions are reviewed by referees with suitable C and ASM experience.

4.2 Update interval

As new functions are submitted, they will added to the library, and the documentation updated. Because this is a volunteer project, and because of the complexity involved in coordinating testing, documentation, and delivery, there will be no fixed interval for updates.

4.3 Version control

NANFOR.LIB will use a numeric version number as follows:

The major version will be numeric, starting from 1. This will change with each quarterly update. The minor version will change with each bug fix. This will start with zero and continue until the next major update, at which point it will revert to zero again.

Typical version numbers might be 1.1, 2.12, 15.2, etc.

The .LIB file, and all associated files, will carry a date stamp corresponding to the day it is released on the CLIPPER forum. The file time stamps shall correspond to the version number (i.e., 1:03am is version 1.3).

4.4 Announcing updates

As the library and its associated documentation are updated, simple announcements will be posted on the CLIPPER forum. This is the only place where an update shall be announced. An update will be announced after it has been successfully uploaded to the appropriate library on CompuServe.

4.5 Bug reports and fixes

The librarian will correlate and verify all bug reports, with the help of the referees. If the referees believe a bug to be serious, they will fix it and the librarian will release a maintenance upgrade immediately. If they consider it a minor bug, they will fix it but wait for the next scheduled upgrade to release it. In this case, a bug fix may be released as a “Patch.”

4.5.1 Patches

A “patch” is simply an ASCII text file containing instructions for editing the source code to a misbehaving function or group of functions. Patches may appear in the CIS library before a maintenance release or quarterly upgrade. A patch file will have a name of the form

PATn.ZIP

where <n> is a number starting from 1. Patches will be numbered sequentially. Patches will be deleted every time a new version of NANFOR.LIB goes on-line.

A patch zipfile may optionally contain .OBJ files to be replaced in user libraries via a LIB utility.

4.6 Technical Support

Technical support will work just as any technical subject on the CompuServe CLIPPER forum works. Users will post questions and suggestions to a particular message area or thread, and anyone who knows the answer should respond. No one is obliged to answer, but it is considered good form to respond with something, even if one doesn’t know the answer.

Support will include help on recompiling the routines or modifying the source.

4.7 Linker Compatibility

In order to assist users of CA-Clipper third party linkers (such as WarpLink or Blinker), NANFOR.LIB may need to broken up into root and overlay sections. How this will be done will be determined when splitting becomes necessary.

The librarian is not responsible for testing every possible linker for NANFOR.LIB compatibility. It is hoped that linker users will submit appropriate link scripts or other documentation for posting in the appropriate section on the CLIPPER forum.

4.8 Splitting NANFOR.LIB by functional category

It is possible that at some future date, it will make sense to split NANFOR.LIB into separate functional areas (e.g., video routines vs. date routines, etc). This RFC will be modified accordingly should that need arise.

5 FUNCTION CODING STANDARDS

The goal of this standard is not to force anyone to rewrite his code for this library, but to create some consistency among the functions so that they may more easily maintained and understood by all CA-Clipper developers, both novice and advanced.

However, it is extremely important that anyone submitting code attach the proper headers and documentation and fill them out correctly. This will make it much easier for code to be added to the library.

5.1 Required sections for each function
5.1.1 Header (author name/etc, version ctrl info)

Figure 1 shows a header that must be included at the top of every piece of source code submitted to the library. This header will work with both CA-Clipper and C code. For ASM code, substitute each asterisk (“*”) with a semicolon (“;”) and delete the slashes (“/”).

/*
 * File......:
 * Author....:
 * CIS ID....: x, x
 * Date......: $Date$
 * Revision..: $Revision$
 * Log file..: $Logfile$
 *
 *
 * Modification history:
 * ---------------------
 *
 * $Log$
 *
 */
Figure 1 - Standard function header.

Note that the date, revision, logfile, and modification history fields will be maintained by the librarian and should not be edited or adjusted by code authors.

The “File” field shall contain the source file name. This is often independent of the individual function name. For example, a function named ft_screen() would be included in SCREEN.PRG. As a rule, source files (.PRG, .C, .ASM) should not have the “FT” prefix.

The “Author” field should have the author’s full name, and CIS number. A CIS number is important, as this will make bug fixing and other correspondence easier.

5.1.2 Public domain disclaimer

Authors shall simply state “This is an original work by [Author’s name] and is hereby placed in the public domain.”

5.1.3 Documentation block
/* $DOC$
 * $FUNCNAME$
 *
 * $ONELINER$
 *
 * $SYNTAX$
 *
 * $ARGUMENTS$
 *
 * $RETURNS$
 *
 * $DESCRIPTION$
 *
 * $EXAMPLES$
 *
 * $SEEALSO$
 *
 * $INCLUDE$
 *
 * $END$
 */

Figure 2 – Standard Documentation Header

The documentation block must be carefully formatted as it is used by the documenter to produce the Norton Guide documentation for the library.

The keywords enclosed in dollar-signs delimit sections of the documentation header analogous to those in the CA-Clipper 5.0 documentation. Documentation should be written in the same style and flavor as the CA material, if possible. Refer to the CA-Clipper documentation for more detail and numerous examples.

The documentation will appear on comment lines between the keywords. Examples are optional. Do not put documentation on the same line as the comment keyword.

Note that the $DOC$ and $END$ keywords serve as delimiters. Do not place any text between $DOC$ and $FUNCNAME$, or any documentation after the $END$ keyword, unless that documentation belongs in the source code file and not in the resultant Norton Guide file.

The $FUNCNAME$ keyword should be followed by the function name, with parentheses, and no arguments or syntax, such as:

$FUNCNAME$            
   ft_screen()

Note the indent for readability. Parentheses shall be added after the function name as shown above.

The $ONELINER$ keyword should be followed by a simple statement expressing what the function does, phrased in the form of a command, e.g.:

$ONELINER$
          Sum the values in an array

The length of the entire $ONELINER$ shall not exceed 60 characters (this is a Norton Guide limitation).

The $SYNTAX$ keyword should be followed by a CA- standard syntax specifier, such as:

$SYNTAX$
         ft_screen( <nTop> [,<nBottom>] ) -> NIL

All parameters have proper prefixes (see paragraph 5.4), and are enclosed in <angle brackets>. Optional parameters are enclosed in [square brackets] as well. An arrow should follow, pointing to the return value. If there is no return value, it should be NIL. Any others should be preceded with the proper prefix (see the CA- Clipper documentation).

The $SEEALSO$ field provides a way to generate cross-references in the Norton Guide help documentation. Use it to point the user to other related functions in the forum toolkit. For example, if ft_func1() is also related to ft_func2() and ft_func3(), the field would look like this:

$SEEALSO$
ft_func2() ft_func3()

Note that fields are separated by spaces and the parentheses are included.

The $INCLUDE$ area allows you to specify what files are included by this function (this will be used to organize the on-line help file, and possibly the master makefile). An example would be

$INCLUDE$
int86.ch int86.inc

Other documentation fields should be self- explanatory. Review the appendix for a sample. All fields are required and must be filled in. Examples should not be considered optional.

5.1.4 Sample header and documentation block

Refer to the Appendix for a sample header and documentation block.

5.1.5 Test driver

A test driver is an optional section of C or CA- Clipper code that will only be compiled under certain circumstances. Developers are encouraged to include a short “test section” in front of their code.

The test driver shall be surrounded by the following pre-processor directives, and placed at the top of the source file:

#ifdef FT_TEST
     [test code]
 #endif

The test driver is currently optional, but authors submitting Clipper code should seriously consider adding it. It is a good way to include short demos within a piece of source code, yet pay no penalty because it is only compiled if needed. It will be invoked when a #define is created that says “#define FT_TEST.” This is a way for submitters to include short test routines with their functions and yet keep it all in one source file. This will be useful to end users.

This test driver may become required in a future version of the RFC.

5.1.6 Code

The source code shall be formatted as described in paragraph 5.4.

5.2 Function names

All NANFOR.LIB functions start with one of two prefixes. If the function is to be called by user programs, then it will begin with the prefix

FT_       ("F", "T", underscore)

Note that “FT” is a mnemonic for “Forum Toolkit.” If the function is “internal” to a module, then it will be prefixed by an underscore:

_FT ( Underscore, "F", "T" )

with no trailing underscore. Examples:

FT_CURDIR() "external"
_ftAlloc() "internal"
5.3 Librarian’s authority to change function names

Some functions will be submitted that either (1) bear a similar name to another function in the library, or (2) bear an inappropriate name. For example, a function called FT_PRINT that writes a character to the screen could be said to be named inappropriately, as a name like FT_PRINT implies some relationship to a printer. The librarian shall have the responsibility to rename submitted functions for clarity and uniqueness.

5.3.1 Changing a function name after it has been released

Once the library is released with a particular function included, then a function name should generally be frozen and not renamed. To do so would probably cause difficulties with users who had used the previous name and are not tracking the changes to the library.

5.4 Source code formatting
5.4.1 Clipper

Clipper code shall be formatted in accordance with CA’s currently defined publishing standard. Although there will surely be some debate over whether this is a good idea, in general, the goal is to provide something consistent that all CA- Clipper developers will recognize.

Minor deviations will be permitted.

The CA standard usually means uppercase keywords, and manifest constants, and lower case everything else.

In addition, identifiers shall be preceded with the proper metasymbol:

 n Numeric
 c Character or string
 a Array
 l Logical, or boolean
 d Date
 m Memo
 o Object
 b Code block
 h Handle
 x Ambiguous type

Refer to the CA-Clipper documentation for samples of CA’s code publishing format.

5.4.2 C

C source code shall be formatted in a generally accepted way, such as Kernighan and Ritchie’s style used in the book _The C Programming Language_.” The use of CA’s EXTEND.H is encouraged.

5.4.3 ASM

No particular formatting conventions are required for assembly language source code, since assembly code formatting is fairly standard. Lowercase code is preferred. Be sure to include the proper documentation header information, as described above.

Do not place ASM code in DGROUP. See paragraph 5.11.

5.5 Organization into .PRGs

Since many different people will be submitting routines, it is probably best if all routines that belong together are housed in the same .PRG. If there is some reason to split the .PRG, the referees and the librarian will handle that as part of library organization.

5.6 Header files

Including a “.ch” or “.h” or “.inc” file with each function would get unwieldy. For the purpose of NANFOR.LIB, all #defines, #ifdefs, #commands, #translates, etc that belong to a particular source file shall be included at the top of that source file. Since few submissions will split over multiple source files, there will usually be no need to #include a header in more than one place.

If a “ch” file will make the end user’s job of supplying parameters and other information to NANFOR.LIB functions easier, then it shall be submitted as a separate entity. The referees will decide on whether to include these directives in a master NANFOR.CH file.

5.7 Clipper 5.0 Lexical Scoping

NANFOR.LIB routines that are written in CA-Clipper will make use of CA-Clipper 5.0’s lexical scoping features to insulate themselves from the rest of the user’s application.

For example, all “privates” shall generally be declared “local.”

If a package of Clipper functions is added to the library, then the lower-level, support functions will be declared STATIC as necessary.

5.8 Use of Publics

Authors shall not use PUBLIC variables in NANFOR.LIB functions, due to the potential interference with an end-user’s application or vice versa.

If a global is required for a particular function or package of functions, that global shall be accessed through a function call interface defined by the author (.e.g, “ft_setglobal()”, “ft_getglobal()”, and so on). Globals such as these shall be declared static in the .PRG that needs them.

5.9 Use of Macros (“&” operator)

The use of macros in NANFOR.LIB functions will be, for the most part, unnecessary. Since this is a CA-Clipper 5.0 library, the new 5.0 codeblock construct should be used instead. Anyone having trouble figuring out how to convert a macro to a codeblock should post suitable questions on the CLIPPER forum on CompuServe.

5.10 Use of Static Functions

Any CA-Clipper 5.0 function that is only needed within the scope of one source file shall be declared STATIC. This applies mostly to NANFOR.LIB “internals” (names with an “_ft” prefix) that user programs need not access.

5.11 Use of DGROUP in ASM Functions

Use of DGROUP in assembly language functions shall be avoided, in accordance with CA’s recommendations. Assembly functions written for NANFOR.LIB shall use a segment named _NanFor, as in the following example:

Public FT_ChDir
Extrn _ftDir:Far
Segment _NanFor Word Public "CODE"
 Assume CS:_NanFor
Proc FT_ChDir Far
 .
 .
 .
 Ret
 Endp FT_ChDir
 Ends _NanFor
End
5.12 Use of "Internals"

Use of CA-Clipper “internals” by code authors is allowed. However, should any code make use of an internal, i.e., a function or variable that is not part of the published CA-Clipper API, then that internal shall be clearly marked in the documentation (under “DESCRIPTION”) and in the actual code, everywhere the internal is used.

5.13 Procedures for compiling functions
5.13.1 Clipper

Clipper functions will be compiled under the current release of CA-Clipper 5.0, with the following compiler options:

/n /w /l /r

Note that neither line numbers nor debugging information will find its way into NANFOR.LIB, to keep the code size down. End users may recompile NANFOR.LIB with these options enabled if they want to view NANFOR.LIB source in the debugger.

5.13.2 ASM

Assembly functions must compile successfully under any MSDOS assembler capable of producing the proper .OBJ file. However, care should be taken not to use any macros or special syntax particular to one vendor’s assembler, because that would make it difficult for end users to recompile the source. The preferred assembler is MASM, followed by TASM.

5.13.3 C

C functions must compile successfully under any C compiler capable of interfacing to CA-Clipper. Obviously, Microsoft C, version 5.1, is the preferred development environment. Care should be taken, when writing C code, not to use any special compiler features particular to one vendor’s C compiler, because that would make it difficult for end users to recompile the source.

5.14 Functions requiring other libraries

It is very easy to write functions in C that call the compiler’s standard C library functions. However, NANFOR.LIB can make no assumptions about the end user’s ability to link in the standard library or any other library. Therefore, no function will be added to NANFOR.LIB that requires any other third party or compiler manufacturer’s library.

6 ADMINISTRATIVE DETAILS

6.1 Librarian

The librarian will be the person who rebuilds the library from the sources and uploads the resulting deliverables to the proper CLIPPER forum library on CompuServe. The librarian generally does *not* test code or edit source code to repair formatting errors.

6.2 Documenter

The documenter is responsible for maintaining the Norton and guides and keeping it in sync with each new release.

6.3 Referees

Referees are volunteers who read source code, clean it up, compile it, look for problems like potentially problematic C code, decide on which function is best, consolidate common functions, etc. They make sure the header and documentation blocks are present. There is no election or term for refereedom. One simply performs the task as long as one can and bows out when necessary.

6.4 Transitions

Not everyone will be able to stay around forever to keep working on this project. Therefore, it is the responsibility of each referee, documenter, or librarian to announce as far in advance as possible his or her intention to leave, in order to give everyone a chance to come up with a suitable replacement. Don’t let it die!

7 CONTRIBUTORS

Current contributors, directly and indirectly, to this document include:

Don Caton [71067,1350]
Bill Christison [72247,3642]
Robert DiFalco [71610,1705]
Paul Ferrara [76702,556]
David Husnian [76064,1535]
Ted Means [73067,3332]
Alexander Santic [71327,2436]
Glenn Scott [71620,1521]
Keith Wire [73760,2427]
Craig Yellick [76247,541]
James Zack [75410,1567]

NOTES :

  • In Harbour library file name of NanForum Toolkit is hbnf.a
  • Maybe some functions :
    • obsoleted,
    • used some low-level hardware access or some OS specific features,
    • so not included in hbnf library.

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Mere Clipper

An article by Roger Donnay, March, 1998
.
We often do not realize the importance of people and events until many years later when the dust has settled and we can put them into perspective. Three years ago I was asked to write an article for the CDGN Magazine. It was titled “Back to the Future” and it dealt with the the role of Clipper in 1995 and into the future. I recently broke out my old copy of CDGN magazine and reread the article to see if my predictions match the current landscape.
.
I predicted that I would be writing my final article about Clipper in the year 2035. Many of you assumed that either I was much younger than I really am, that this was a typographical error, or that I had already lost it and was living on a ranch somewhere in California with Ronald Reagan. None of the above are true. I am now fifty-four years old. In the year 2035, I will be 91 years old but I will still be programming because in the year 2007 we will discover a new drug that restores dead brain cells. The year 2035 will mark the year that we finally arise from the ashes of the “great computer meltdown” of 2010. The meltdown will occur because of the Year 2000 debacle which will create a world-wide depression and create a political climate of hatred towards programmers that will build to a frenzy leading to “The Night of Broken Disks”. Computer programmers will be fleeing to Russia, Iran and Iraq – the only safe havens in the world that will not be affected by the “Great-Satan Virus” due to their refusal to connect to the Information SuperHighway.
.
This great oppression of computer programmers will force those who are not killed outright, or sent to “de-programming camps” made their escape to third-world countries to hide for years in attics, befriended by a few, brave souls who know it is not their fault they were born “computer-literate”. During this 20-year war on computers, an arsenal of “giant magnets” are created by the new war machine and the industrialized cities of the world are bombed with the largest “de-gaussing” campaign in history. No piece of software or database will be safe from annilation. Finally, the great war machine is defeated because it will fail to realize that it cannot maintain such a war when it destroys the very machines and software that allow it to wage war.When it is all over, a discovery is made in a little house on the Prinsengracht in Amsterdam. A old notebook computer is found in the attic and sent to a museum. While restoring the computer, a small disk is found, still fused in the disk drive. Because of its condition, it appears that the notebook had been there for many years. Much work goes into the restoration of the disk and its data and finally, it is discovered that the disk contains the diary of a young, computer-literate girl who had lived in hiding for many years. By this time, the only computer-literate people left in the world only speak Russian or Farsi, so it takes much effort to figure out how to decipher the data on the disk. Finally, a compelling and sad story emerges about a young girl who struggles to maintain her innocence, her sanity, her computer-proficiency, and her faith in God while hiding from the great de-gaussing and de-programming regime.
.

It is a sad story, and it takes time for the world to really understand her story, especially her references to “The Book of Clipper”. What was Clipper? Was this what helped her maintain her sanity and her faith in God? What happened to the young girl? Her story spreads around the world, and a never-ending search continues for a copy of “The Book of Clipper”. Finally, the search ends in a little Russian town. Not a single person realizes that “The Book of Clipper” is a reference to the manual for the computer language that every single Russian speaks fluently, until someone finds a copy of the manual that Larry Heimendinger had left at the only Russian Clipper conference ever held – in 1992. It is dusty and worn, but it is the only book left that tells the true story of Clipper. Even though every programmer in Russia can speak Clipper, not a single one of them has seen a copy of “The Book of Clipper” because none had ever been sold. The software had been pirated, and then spread from disk to disk throughout the country while the story of Clipper passed from mouth to mouth. The Russians are the only civilized society that still has a programming language, so they offer it as a gift to the world, and the world becomes whole again, and the people rejoyce, and I come out of hiding – to write my final article about Clipper.

It’s a Wonderful Life

I like to imagine that I am the angel in the story “It’s a Wonderful Life” and that I have been called on by God to rescue a person who feels that his life has been lived in vain. In my rendition of the story, the desperate soul is not George Bailey but instead is Tom Rettig. Tom passed away about a year ago and I find myself haunted by him because I feel that I have never given back to him what he gave to me and the rest of the world. I often think back at what my life was like in the mid 80’s. After many successful years as an Electronics Engineer my life was just not working anymore. Thieves broke into my business office and stole my computers and my software (including the backups). I was struggling with a failing computer-accessories manufacturing business that had pushed me deep into debt, and then my wife decided to just leave one day and head for greener pastures. I thought she had been kidnapped because she disappeared without a trace.

Arlo Guthrie once wrote a song about “The Last Man”. He said “You think you’ve got it bad? Look at that guy?.” I WAS that guy.

Then, one day, in early 1986 I was struggling with a problem trying to get dBase-III to work properly on my new peer-to-peer network. I recall making a tech support call to the network developer and the person on the phone asked “Are you compiling with Clipper?”

This simple question, in retrospect, was equivalent to someone posting a huge sign “Except a man be born again, he cannot see the kingdom of God”. Clipper was my salvation. It allowed me to layeth down in green pastures and it restoreth my soul. So how did it come about that a person could be saved from the depths of depravity by a mere software product? We all have our stories of salvation, and they all take us down different paths but they all lead to the same place. My story in not unlike C.S. Lewis’ story in “Mere Christianity”, except the players are different. The Book of Clipper is not one story, but hundreds of stories all evolving from the “Platitudes of Vulcan”.

Tom Rettig entered the scene around 1986 and offered an add-on product to Clipper titled “Tom Rettig’s Library”. Tom was a well-liked, generous person who eventually offered his library into the public-domain. Some of us are old enough to remember him as Jeff, the small boy in the original “Lassie” series on television in the 50’s. I first met him at a user group in Southern California. After the meeting we went to a bar for a few beers and he sat and talked to us like we had all known him for years. He inspired us to do what he did, because he was just like us. The next day, I thought “If Tom Rettig can make a successful add-on product to Clipper, so can I”. I wasn’t the only person who had seen the light that night. Tom had broken new ground, had planted the first seeds, and from these seeds, an entire community of user-groups, programmers, applications, add-on products, books, magazines, et al, grew into maturity.

Two Steps Back

Have you ever heard anyone say “He’s so far behind he’s ahead”? By now, most of you have decided that you must move on to Windows and that there is no place for Clipper in your strategy. Many of you have already done so and are experimenting with products like VO, Delphi, VB, and Power-Builder or have created applications with these development environments. I am not writing this article to suggest that in any way, this was a bad choice. I have spent sufficient time with these products to come to the realization that Windows applications can be developed by travelling many different paths. What I am offering, however, is another perspective; one that frees us to open our minds to look at the future from a different view. Many of us have been so busy and so worried about constantly moving forward that we have forgotten how we got here in the first place, by the use of an enduring and powerful language – Clipper.

So you may be thinking “What is he talking about? Clipper is Dead!”. In the sense of a product, this may be true, but in the sense of a language, it is far from true. Let’s imagine that Chinese is packaged into a product named “Visual-Chinese” and this product includes a set of design-tools for creating quick-Chinese documents that can be easily integrated into our marketing documents. Soon we would find our business opened up to a new market of 1 billion people. The product becomes instantly successful and everyone love its and uses it – until, years later, when we find that our marketing documents are not delivering any sales. Why? Because the language had to be cut and trimmed to fit into the limitations of the software environment. It becomes ambiguous, arrogant and unwanted by the very people who inspired its development, so it dies and Visual-Chinese gets thrown away like every other Visual tool. Does this mean that the Chinese language dies with the product? No. Chinese is a language that will endure. It has lots of users; it is robust, and it is mature.

The key word is “language“. Development strategies should be built around the choice of a proper language, not just a product. Clipper is a language that endures. It cannot die. It has widespread use around the world and there are hundreds of thousands of Clipper legacy applications still doing mission- critical work. Unfortunately, because the word “Clipper” is owned by CA, and because CA has essentially abandoned Clipper, it cannot endure under the name Clipper, so it must endure under another name: that name is “Xbase”. Software developers try to treat languages like they own them, but they are only temporary custodians. This leads us to a discussion of the current state of the Xbase language. Xbase currently ( 1998 ) exists in 5 dialects:

      1. dBase – A Windows-based Interpreter.
      2. FoxPro – A Windows-based Interpreter.
      3. CA-Clipper – A DOS-based Xbase compiler.
      4. CA-VO – A 32-bit Windows-based Xbase compiler.
      5. Xbase++ – A 32-bit Multi-Platform Compiler.

Xbase as dBase

dBase was the custodian of the Xbase language from around 1983 until about 1987. Unfortunately, it was an interpretive language so it never gained respectability as a true, robust language, however, it had much to offer the developer in ease-of-use and database design. dBase continues to be supported by Borland, simply because there is still money to be made in upgrades and conferences, but Borland has made it clear that they intend to make dBase programmers learn how to speak Pascal and eventually will phase Xbase out of their products.

Xbase as FoxPro

FoxPro took over as a co-custodian of the Xbase language in about 1987 and emerged around the same time as Clipper. FoxPro defeated dBase nearly overnight simply because it was faster, not because it delivered any new language concepts. FoxPro continues to be supported by Microsoft, simply because there is still money to be made in upgrades and conferences, but Microsoft has made it clear that they intend to make FoxPro programmers learn how to speak Visual Basic and eventually will phase Xbase out of their products.

Xbase as Clipper

Clipper was undoubtely the best custodian of the Xbase language from 1987 to 1996. Clipper introduced the Xbase compiler, the open-architecture concept of the extend system, code blocks, locals, statics, multi-dimensional arrays, the RDD layer, the preprocessor, and language extensions. Clipper was the first Xbase custodian to give Xbase respectability as a true programming language. Clipper maintained this respectability until around 1996 when CA released CA-Clipper 5.3. CA chose to treat Clipper as a “package” rather than a “language” and alienated nearly the entire Clipper community when they bundled a Windows-IDE and several third-party products into the package. This was when Clipper died.

Xbase as VO

Computer Associates planned for VO to take over as the custodian of the Xbase language by forcing the death of Clipper and dragging CA customers into a new kind of development environment that kind of looks like Clipper, in that it inherited much of the new Clipper extensions. Unfortunately, migration to VO became cumbersome due to too many incompatabilities, poor performance, poor reliability and a third-party community who could not get their products to work with VO. VO promised it would be easy to migrate existing Clipper applications to Windows but could not deliver on the promise. Working in VO is in no way similar to working in Clipper. Many Clipper developers find that using a third-party Windows library (like Five-Win or Clip-4-Win) with Clipper is a much easier migration path than VO.

Why Xbase?

Many of us wonder why Xbase has not been given more respectability as a “mainstream” language. If Xbase is so good, why are Borland and Microsoft phasing it out of their future products? I was watching a television program the other day about an analysis of automobile technology over the years. We often assume that the best technology is what endures over time and that it eventually rises to the top. This may be true in an ideal world, but in a capitalist society, it is usually market dog-fights that determine dominance. In this analysis, it was determined that steam technology could have produced cars just as good as internal combustion technology, but Henry Ford chose the latter. Bill Gates has chosen Basic, not because it is better, but because he owns it. He doesn’t own Xbase, and Bill cannot embrace something that he cannot control. Borland chose Pascal. Not because it is better, but becaused they own it.

Over the past 10 years, the success of the Xbase products has been due to the high degree of abstraction of the Xbase language, which makes it vastly simpler to acces and use operating system functions and resources. In addition, Xbase is more than just a specialized programming language, a database navigation language, or a user interface language – instead, it combines all of these roles, harmoniously integrating them with one another.

Xbase offers dynamic data types and is generally described as being highly “tolerant“. Taken together, these benefits have persuaded a steadily growing community of users and developers to rely upon it as a choice for implementing mission-critical and commercial PC-desktop applications. In fact, world-wide, more than one-third of all DOS-based commercial applications now in use were written in Xbase, with Clipper accounting for the major share.

Square Pegs and Round Holes

Most Windows programmers will tell you that you cannot take a standard Clipper application with @SAY..GETS, Menu Prompts, etc, and convert it to a Windows GUI program without a major change in the architecture and the functionality of the program. They claim that a text-based, modal design has too little in common with GUI-based, event-driven, non-modal design. They will tell you that it like trying to fit a square peg into a round hole. For years, I believed this because it made sense. I, like everyone else, wrote my Windows applications with a different structure than my Clipper applications. They were built around an event model rather than a procedural model and the code was tightly-bound rather than loosely-bound to the functional model. This always leaves me with an uneasy feeling because it forces me to write applications that are less modular and are platform specific. Microsoft, Borland, and CA each wants us to build applications their way. They want us to learn their programming tools, their methods, their plug-ins, their workshops, and their studios – not their language. Why? Because applications built around their environment will be harder to migrate to competitor’s products than applications built around a language.

So they make sure that the language is difficult and inaccessible, and that the application cannot be maintained or migrated to any other platform, other than platforms that they support. Programmers, however, have to survive in the real world and this requires platform flexibility. The reason why so many mission- critical DOS applications are still surviving in the real world is because each development platform supports DOS as a subset, so DOS has been, out of necessity, elevated to the status “platform independent”. I can run my Clipper applications under MS-DOS, PC-DOS, DR-DOS, OS/2, Windows 3.1, Windows 95, Citrix- Winframe, MULTI-DOS, Windows NT and Novell-DOS. I can run my Delphi applications only under 32-bit Windows. Is this a step forward?

Cocoon

In my dream, the “Ghost of Xbase Future” led me through the Land of Clipper and how it might look like up through the year 2035. I couldn’t hold back my emotions as I witnessed the data meltdown and the termination of millions of programmers. I asked him “Spirit – is this a vision of how things MUST be or how things COULD be?” He never answered me. I woke up from my dream and ran to the mirror. I was relieved to see that I wasn’t 91 years old but was still a young man. I exclaimed “There’s still time!” I bolted to the window, looked out, and saw that The Land of Clipper looks different than it did yesterday. The paths are 32-bits wide and they lead everywhere, yet they look familiar and something tells me that there is nothing to fear at the end of these paths. Then I realized that I had not been dreaming and that Clipper had not really died at all but had been in a cocoon, waiting to metomorphose into a butterfly, one with big X’s on it’s wings. The butterfly is beautiful and it attracts the attention of people like Dirk Lesko (author of Funcky), of Jud Cole (author of Blinker), of Dave Kuechler (author of Comix), and others who once frolicked in the land of Clipper.

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Note: This article is a summary  ( by courtesy of author) original is here.