UNCOL
UNCOL (Universal Computer Oriented Language) is a universal intermediate language for compilers. The idea was introduced in 1958, by a SHARE ad-hoc committee.{{cite journal |last1=Strong |first1=J. |last2=Wegstein |first2=J. |last3=Tritter |first3=A. |last4=Olsztyn |first4=J. |last5=Mock |first5=O. |last6=Steel |first6=T. |title=The Problem of Programming Communication with Changing Machines: A Proposed Solution |journal=Communications of the ACM |date=August 1958 |volume=1 |issue=8 |pages=12–18 |doi=10.1145/368892.368915 |doi-access=free }} It was never fully specified or implemented; in many ways it was more a concept than a language.
UNCOL was intended to make compilers economically available for each new instruction set architecture and programming language, thereby reducing an N×M problem to N+M.{{cite mailing list |url=https://mailarchive.ietf.org/arch/msg/dmarc/mWIrFuomDC50hxgPi4QvO8VM6yQ |title=UNCOL and Reversing modifications from mailing lists |date=23 November 2021 |access-date=24 November 2021 |mailing-list=dmarc-ietf |author=John Levine}} Each machine architecture would require just one compiler back end, and each programming language would require one compiler front end. This was a very ambitious goal because compiler technology was in its infancy, and little was standardized in computer hardware and software.
History
The concept of such a universal intermediate language is old: the
SHARE report (1958) already says "[it has] been discussed by many independent persons as long ago as 1954." Macrakis (1993) summarizes its fate:
{{quote|UNCOL was an ambitious effort for the early 1960s. An attempt to solve the compiler-writing problem, it ultimately failed because language and compiler technology were not yet mature.
In the 1970s, compiler-compilers ultimately contributed to solving the problem that UNCOL set itself: the economical production of compilers for new languages and new machines.}}
UNCOL is sometimes used as a generic term for the idea of a universal intermediate language. The Architecture Neutral Distribution Format is an example of an UNCOL in this sense, as are various bytecode systems such as UCSD Pascal's p-code, and most notably Java bytecode.John English, Introduction to Operating Systems: Behind the Desktop, Palgrave MacMillan 2005, {{isbn|0230374085}}, p. 10
See also
Notes
References
- {{cite journal|last1=Conway|first1=Melvin E.|title=Proposal for an UNCOL|journal=Communications of the ACM|date=1 October 1958|volume=1|issue=10|pages=5–8|doi=10.1145/368924.368928 |issn=0001-0782|doi-access=free}}
- Jean E. Sammet, Programming Languages: History and Fundamentals, Prentice-Hall, 1969. Chapter X.2: UNCOL (Significant Unimplemented Concepts), p. 708.
- SHARE Ad-Hoc Committee on Universal Languages (J. Strong, J. Olsztyn, J. Wegstein, O. Mock, A. Tritter, T. Steel), "The Problem of Programming Communication with Changing Machines", Communications of the ACM 1:8:12–18 (August 1958) and 1:9:9–15 (September 1958).
- Stavros Macrakis, "From UNCOL to ANDF: Progress in Standard Intermediate Languages", White Paper, Open Software Foundation Research Institute, RI-ANDF-TP2-1, January, 1992. Available at [http://citeseer.ist.psu.edu/macrakis93from.html CiteSeer]
- T.B. Steel, Jr., "UNCOL: Universal Computer Oriented Language Revisited", Datamation (Jan/Feb 1960), p. 18.
- T.B. Steel, Jr., "A First Version of UNCOL", Proc. Western Joint Computer Conference 19:371 (Los Angeles, May 9–11, 1961).
- T.B. Steel, Jr., "UNCOL: The Myth and the Fact", Annual Review in Automatic Programming 2:325 (1961).