Editing Clipper (programming language)

{{Short description|Compiler for xBase}}
{{Infobox programming language
| name = Clipper
| logo = 
| logo caption = 
| paradigm = 
| family = [[xBase]]
| designer = 
| developers = [[#History|Nantucket Corporation]]<br/>[[Computer Associates]]
| released = {{Start date and age|1985}}
| latest release version = CA Clipper 5.3b
| latest release date = {{Start date and age|1997|05|20}}
| discontinued = yes
| typing = 
| programming language = 
| operating system = [[DOS]]
| license = [[Proprietary software|proprietary]]
| file ext = 
| website = Last known Website ''{{URL|http://www.grafxsoft.com/clipper.htm}}'' still exists, but relevant content has been removed, even for the main webpage. Looking back in time at this URL in Wayback Machine, real content appears last available on June 16, 2018. This archived content still available at: ''{{URL|https://web.archive.org/web/20180616231447/http://www.grafxsoft.com/clipper.htm}}''. Trying to place an order at the page bottom will fall.
| wikibooks = 
| implementations = 
| dialects = 
| influenced by = [[dBase]]
| influenced = [[Harbour (programming language)|Harbour]]
}}
'''Clipper''' is an [[xBase]] [[compiler]] that implements a variant of the ''xBase'' computer [[programming language]]. It is used to create or extend software programs that originally ran usually on [[DOS]]. Although it is a powerful general-purpose programming language, it was used mainly to create [[database]] business programs.
 
One major [[dBase]] feature not implemented in Clipper is the [[dBase#Interactivity|dot-prompt]] (. prompt) interactive command set,<ref>{{cite book |title=DBASE - From the Dot Prompt: An Introduction to Structured Programming using dBase IV |url=https://books.google.com/books?isbn=0791417808 |isbn=0791417808 |author=Warren M. Littlefield |date=1983}}</ref> which was an important part of the original dBase implementation.

Clipper, from Nantucket Corp and later [[Computer Associates]], started out as a native code compiler for dBase III databases, and later evolved.<ref>{{cite web |title=Clipper |url=https://winworldpc.com/product/clipper |quote=a native code compiler for dBase ... later evolved ...}}</ref>

==History==
Clipper was created by Nantucket Corporation, a company that was started in 1984 by Barry ReBell (management) and Brian Russell (technical). Larry Heimendinger was Nantucket's president.<ref name=Bar/> In 1992, the company was sold to [[Computer Associates]] for 190 million dollars and the product was renamed to CA-Clipper.<ref>{{Cite web |url=https://vivaclipper.wordpress.com/tag/ca-clipper/ |title=CA-Clipper |website=Viva Clipper! |date=14 September 2013}}</ref><ref>GrafX Software licensed CA-Clipper in 2002 from CA for ongoing marketing and distribution.</ref>

Clipper was created as a replacement [[programming language]] for [[Ashton Tate]]'s ''[[dBASE]] III'', a very popular [[database language]] at the time. The advantage of Clipper over dBASE was that it could be [[Compiler|compiled]]<ref>[[Compiler|Compiling]] dBASE code changes it from [[Interpreter (computing)|interpreted]] code, which must be interpreted every time each line of code is executed, to [[p-code machine|p-code]], which uses a [[virtual machine]] to process the compiled p-code. p-code is considerably faster, but still not as fast as the [[machine language|machine code]] generated by native compilers. As a technical marketing ploy, the p-code was wrapped into object code (linkable .obj files) which gave the impression that it was compiled to native code.</ref> and [[Execution (computing)|executed]] on [[DOS]] as a [[Computer software|standalone application]]. In the years between 1985 and 1992, millions of Clipper applications were built, typically for small businesses dealing with databases concerning many aspects of [[Customer relationship management|client management]] and [[Inventory management software|inventory management]]. For many smaller businesses, having a Clipper application designed to their specific needs was their first experience with software development. Also many applications for [[banking]] and [[insurance companies]] were developed, here especially in those cases where the application was considered too small to be developed and run on traditional [[mainframe]]s. In these environments Clipper also served as a [[Debugger front-end|front end]] for existing mainframe applications.<ref>{{Cite web |url=http://www.thocp.net/software/languages/clipper.htm |title=Clipper |date=20 June 2007 |website=thocp.net |publisher=The History Of Computing Project |access-date=24 August 2016 |url-status=dead |archive-url=https://web.archive.org/web/20080512215826/http://www.thocp.net/software/languages/clipper.htm |archive-date=12 May 2008}}</ref>

As the product matured, it added elements of the programming languages [[C (programming language)|C]] and [[Pascal (programming language)|Pascal]], and [[object-oriented programming]] (OOP), and the code-block [[datatype|data-type]] (hybridizing the concepts of dBase [[Macro (computer science)|macros]], or [[string (computer science)|string]]-evaluation, and [[function pointer]]s), to become far more powerful than the original. Nantucket's Aspen project later matured into the [[Microsoft Windows|Windows]] native-code CA-[[Visual Objects]] compiler.<ref name=DobCA95>{{cite magazine |last1=da Silva |first1=Rod |date=October 1, 1995 |url=http://www.drdobbs.com/database/examining-ca-visual-objects/184409649 |title=Examining CA-Visual Objects |magazine=[[Dr. Dobb's Journal]]}}</ref>

==Market penetration==
Nantucket sold well in Western markets. Also, in November 1991, the ''New York Times'' reported the company's success in "painstakingly convincing Soviet software developers that buying is preferable to pirating". According to the article, Clipper had sold 2,000 copies in the Soviet Union<ref name=Bar>{{cite news |last1=Rifkin |first1=Glenn |date=3 November 1991 |url=https://www.nytimes.com/1991/11/03/business/selling-software-soviet-style.html |title=Selling Software, Soviet-Style |work=[[The New York Times]]}}</ref> (compared to 250,000 worldwide).

===Decline===
In the early 1990s, under new ownership,<ref name=DobCA95/> Clipper failed to transition from [[DOS]] to [[Microsoft Windows|Windows]]. As a result, almost no new commercial applications were written in Clipper after 1995.

By then, the "classically trained programmer" commonly used [[Strong and weak typing|strong typing]], in contrast to the original dBASE language. An evolution of Clipper, named VO, added strong typing but made it optional, to remain compatible with existing code.<ref name=DobCA95/> Four of the more important languages that took over from Clipper were [[Visual Basic]], [[Microsoft Access]], [[Delphi (software)|Delphi]], and [[Powerbuilder]]. All provided strong typing.

===Revival by third-parties===
The Clipper language is being actively implemented and extended by multiple organizations/vendors, like ''[[XBase++]]'' from Alaska Software and ''FlagShip'', and [[free software|free]] ([[GNU General Public License|GPL]]-licensed) projects like ''[[Harbour (software)|Harbour]]'' and ''xHarbour''.<ref>{{cite web |author1=fbizzell |date=January 31, 2006 |url=https://www.tek-tips.com/viewthread.cfm?qid=1184854 |title=Converting Clipper applications to windows}}</ref>

Many of the current implementations are portable ([[DOS]], [[Windows]], [[Linux]] ([[32-bit computing|32-]] and [[64-bit computing|64-bit]]), [[Unix]] (32- and 64-bit), and [[macOS]]), supporting many language extensions,<ref>{{Cite web |url=http://www.xharbour.org/index.asp?page=product/extensions |title=xHarbour.org |website=www.xharbour.org}}</ref> with much extended [[runtime library|runtime libraries]], and various Replaceable Database Drivers (RDD) supporting many popular database formats, like [[dBase|DBF]], DBTNTX, DBFCDX ([[Visual FoxPro|FoxPro]], Apollo, Comix, and Advantage Database Server), MachSix (SIx Driver and Apollo), [[SQL]], and more. These newer implementations all strive for full compatibility with the standard [[dBase]]/[[xBase]] syntax, while also offering OOP approaches and target-based syntax such as <code>SQLExecute()</code>.

===Usenet===
The Clipper [[Usenet]] [[newsgroup]]s are [https://groups.google.com/group/comp.lang.clipper comp.lang.clipper] and [https://groups.google.com/group/comp.lang.clipper.visual-objects comp.lang.clipper.visual-objects].

[[File:Clipper Helloworld.png|thumb|400px|Compiling and running hello world program in clipper]]

== Programming in Clipper ==

A simple [["Hello, World!" program|hello world]] - application:

 ? "Hello World!"

A simple data base input mask:

 USE Customer SHARED NEW
 clear
 @  1, 0 SAY "CustNum" GET Customer->CustNum PICT "999999" VALID Customer->CustNum > 0
 @  3, 0 SAY "Contact" GET Customer->Contact VALID !empty(Customer->Contact)
 @  4, 0 SAY "Address" GET Customer->Address
 READ

== Version history ==
The various Clipper versions, and release dates, were:

From Nantucket Corporation; the "seasonal versions", billed as "[[dBase]] [[compiler]]s":

* Nantucket Clipper Winter'84 – May 25, 1985
* Nantucket Clipper Summer'85 – 1985
* Nantucket Clipper Winter'85 – January 29, 1986
* Nantucket Clipper Autumn'86 – October 31, 1986
* Nantucket Clipper Summer'87 – December 21, 1987

From Nantucket Corporation; Clipper 5:

* Nantucket Clipper 5.00 – 1990
* Nantucket Clipper 5.01 – April 15, 1991
* Nantucket Clipper 5.01 Rev.129 – March 31, 1992

<!-- Deleted image removed: [[File:CA-Clipper 5.2 manual cover.png|180px|right|A Clipper 5.2 manual cover.]] -->and from [[Computer Associates]]; CA-Clipper 5:

* CA Clipper 5.01a –
* CA Clipper 5.20 – February 15, 1993
* CA-Clipper 5.2a – March 15, 1993
* CA Clipper 5.2b – June 25, 1993
* CA-Clipper 5.2c – August 6, 1993
* CA Clipper 5.2d – March 25, 1994
* CA-Clipper 5.2e – February 7, 1995
* CA Clipper 5.30 – June 26, 1995
* CA Clipper 5.3a – May 20, 1996
* CA Clipper 5.3b – May 20, 1997

=== Clipper Tools ===
After buying Nantucket, along with the standard Clipper [[Library (computing)|library]], CA developed another, named ''Clipper Tools''. Three versions of this library were released, alongside Clipper versions. This library became a de facto standard among Clipper clones, such as xHarbour. It was also cloned by several of Clipper's clones.

==References==
{{Reflist}}

==External links==
*[https://www.sourceforge.net/projects/fglib Free Open Source Graphic, GUI & Form Designer for CA-Clipper]
*[http://www.davep.org/clipper/ mini Clipper FAQ] {{Webarchive|url=https://web.archive.org/web/20021211220811/http://www.davep.org/clipper/ |date=2002-12-11}}
*[http://www.printfil.com/article/clipper-print-windows-printer.htm Print from Clipper to newest Windows printers] article
*[https://harbour.github.io/the-oasis/ The Oasis] is the largest file archive for CA-Clipper and xBase on the web
*[https://harbour.github.io/ Harbour Project] A 32/64 bit multiplatform Clipper compiler
*[https://www.linguagemclipper.com.br/ CA-Clipper Website]

{{xBase}}
{{Authority control}}

[[Category:1985 software]]
[[Category:Fourth-generation programming languages]]
[[Category:DOS software]]
[[Category:Dynamic programming languages]]
[[Category:Dynamically typed programming languages]]
[[Category:High-level programming languages]]
[[Category:Programming languages]]
[[Category:Programming languages created in 1985]]
[[Category:XBase programming language family]]
[[Category:Table-oriented programming]]
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