LOLITA(ID:292/lol003)Symbolic mathematics systemLanguage for the On-Line Investigation and Transformation of Abstractions. F Blackwell, 1967, TRW for Rome Aircraft Base (NY) Extension of Culler-Fried STL system for symbolic mathematics by the addition of low-level list processing facilities. As it was a CFS, it had simple push-button assignments for many operations, including Had a special memory store, the Symbol Accumulator (SA) DLIST - list symbols DSYM - create a symbol LS - load a symbol into SA SSB - store symbol before SSA - Store symbol after ES - erase symbol CON - concatentate symbols SI - set index II - increment index CFS remained simple, but the user could (and did) develop complicated systems with it. People: Related languages
References: INTRODUCTION The purpose of the study described in this paper was to develop a computer program that enables users arbitrarily to define symbols and to instruct the computer to manipulate and to operate with them on-line according to the rules of their definition. An additional goal was the use of this symbol manipulation capability for constructing on-line programs that perform analytic operations upon algebraic expressions; the results of this work will be briefly mentioned in this paper. Although modest in size, this work represents a union between two areas of the computer field receiving increasing attention: symbol manipulation and online systems. Such a merge has, of course, already occurred through the adaptation for on-line use of some of the traditional symbol manipulation languages, such as LISP 1 and IPL-V. 2 The study reported here was an attempt to develop a small system sufficiently versatile to lie at the foundation of larger systems and languages. Its culmination was in a programming language hesitatingly called LOLITA. Since a symbol is an abstraction, the acronym LOLITA is properly descriptive: Language for the On-Line Investigation and Transformation of Abstractions. This paper will be devoted largely to a description of this language, together with appropriate information about the on-line system of which it part in its implementation at TRW Systems. Extract: Design considerations Design considerations LOLITA was designed as a general symbol manipulation language that would be useful in an on-line environment. It should be noted that nothing in the language precludes its use in a batch processing mode, and it appears that it would be very satisfactory employed in this way. In its present implementation as an on-line language, it is executed interpre tively, and in fact is a part of the extended Culler-Fried on-line system at TRW Systems. However, it is not closely tied to this latter system, and with some additional programming could operate independently of it or in the framework of any of several other online systems. Perhaps the most important design criterion was that of simplicity. Simplicity in concept, implementation, and use of the language were all to be emphasized, although not at the expense of producing a trivial product incapable of application to a moderately complex problem. The approach chosen was in contrast to that of implementing an existing or creating a new powerful, high-level language for on-line symbol manipulation; rather, it was desired to find a small set of elementary symbol manipulation operators that could be programmed on-line in a hierarchical fashion to create new, higher-level operators capable of carrying out much more complex tasks. An additional significant advantage of the above described approach is the relative ease with which the system can be written for another computer. To accomplish this, one need only rewrite the elementary operators and basic memory allocation routines in the language of the new machine, together with such monitor and control programs as may be needed. In the TRW on-line system, elementary operators occupy only about l O00 words, including a rather flexible display program. in Proceedings of the 22nd national ACM conference 1967, Washington, D.C. view details in Proceedings of the twenty-fourth ACM national conference August 1969 view details in Proceedings of the twenty-fourth ACM national conference August 1969 view details The exact number of all the programming languages still in use, and those which are no longer used, is unknown. Zemanek calls the abundance of programming languages and their many dialects a "language Babel". When a new programming language is developed, only its name is known at first and it takes a while before publications about it appear. For some languages, the only relevant literature stays inside the individual companies; some are reported on in papers and magazines; and only a few, such as ALGOL, BASIC, COBOL, FORTRAN, and PL/1, become known to a wider public through various text- and handbooks. The situation surrounding the application of these languages in many computer centers is a similar one. There are differing opinions on the concept "programming languages". What is called a programming language by some may be termed a program, a processor, or a generator by others. Since there are no sharp borderlines in the field of programming languages, works were considered here which deal with machine languages, assemblers, autocoders, syntax and compilers, processors and generators, as well as with general higher programming languages. The bibliography contains some 2,700 titles of books, magazines and essays for around 300 programming languages. However, as shown by the "Overview of Existing Programming Languages", there are more than 300 such languages. The "Overview" lists a total of 676 programming languages, but this is certainly incomplete. One author ' has already announced the "next 700 programming languages"; it is to be hoped the many users may be spared such a great variety for reasons of compatibility. The graphic representations (illustrations 1 & 2) show the development and proportion of the most widely-used programming languages, as measured by the number of publications listed here and by the number of computer manufacturers and software firms who have implemented the language in question. The illustrations show FORTRAN to be in the lead at the present time. PL/1 is advancing rapidly, although PL/1 compilers are not yet seen very often outside of IBM. Some experts believe PL/1 will replace even the widely-used languages such as FORTRAN, COBOL, and ALGOL.4) If this does occur, it will surely take some time - as shown by the chronological diagram (illustration 2) . It would be desirable from the user's point of view to reduce this language confusion down to the most advantageous languages. Those languages still maintained should incorporate the special facets and advantages of the otherwise superfluous languages. Obviously such demands are not in the interests of computer production firms, especially when one considers that a FORTRAN program can be executed on nearly all third-generation computers. The titles in this bibliography are organized alphabetically according to programming language, and within a language chronologically and again alphabetically within a given year. Preceding the first programming language in the alphabet, literature is listed on several languages, as are general papers on programming languages and on the theory of formal languages (AAA). As far as possible, the most of titles are based on autopsy. However, the bibliographical description of sone titles will not satisfy bibliography-documentation demands, since they are based on inaccurate information in various sources. Translation titles whose original titles could not be found through bibliographical research were not included. ' In view of the fact that nany libraries do not have the quoted papers, all magazine essays should have been listed with the volume, the year, issue number and the complete number of pages (e.g. pp. 721-783), so that interlibrary loans could take place with fast reader service. Unfortunately, these data were not always found. It is hoped that this bibliography will help the electronic data processing expert, and those who wish to select the appropriate programming language from the many available, to find a way through the language Babel. We wish to offer special thanks to Mr. Klaus G. Saur and the staff of Verlag Dokumentation for their publishing work. Graz / Austria, May, 1973 in Proceedings of the twenty-fourth ACM national conference August 1969 view details |