In computing TMG (TransMoGrifier) is a

recursive descent In computer science, a recursive descent parser is a kind of top-down parser built from a set of mutually recursive procedures (or a non-recursive equivalent) where each such procedure implements one of the nonterminals of the grammar. Thus t ...

compiler-compiler In computer science, a compiler-compiler or compiler generator is a programming tool that creates a parser, interpreter, or compiler from some form of formal description of a programming language and machine. The most common type of compiler ...

developed by Robert M. McClure and presented in 1965. TMG ran on systems including

OS/360 OS/360, officially known as IBM System/360 Operating System, is a discontinued batch processing operating system developed by IBM for their then-new System/360 mainframe computer, announced in 1964; it was influenced by the earlier IBSYS/IBJO ...

and early

Unix Unix (; trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and ot ...

. It was used to build EPL, an early version of

PL/I PL/I (Programming Language One, pronounced and sometimes written PL/1) is a procedural, imperative computer programming language developed and published by IBM. It is designed for scientific, engineering, business and system programming. I ...

Douglas McIlroy Malcolm Douglas McIlroy (born 1932) is a mathematician, engineer, and programmer. As of 2019 he is an Adjunct Professor of Computer Science at Dartmouth College. McIlroy is best known for having originally proposed Unix pipelines and developed se ...

ported TMG to an early version of Unix. According to

Ken Thompson Kenneth Lane Thompson (born February 4, 1943) is an American pioneer of computer science. Thompson worked at Bell Labs for most of his career where he designed and implemented the original Unix operating system. He also invented the B programm ...

, McIlroy wrote TMG in TMG on a piece of paper and "decided to give his piece of paper his piece of paper," hand-compiling

assembly language In computer programming, assembly language (or assembler language, or symbolic machine code), often referred to simply as Assembly and commonly abbreviated as ASM or asm, is any low-level programming language with a very strong correspondence b ...

that he entered and assembled on Thompson's

system running on

PDP-7 The PDP-7 was a minicomputer produced by Digital Equipment Corporation as part of the PDP series. Introduced in 1964, shipped since 1965, it was the first to use their Flip-Chip technology. With a cost of , it was cheap but powerful by the s ...

. Thompson used TMG in 1970 as a tool to offer Fortran, but due to memory limitations of PDP-7 ended up creating the B programming language which was much influenced by

BCPL BCPL ("Basic Combined Programming Language") is a procedural, imperative, and structured programming language. Originally intended for writing compilers for other languages, BCPL is no longer in common use. However, its influence is still ...

. The recursive descent algorithm of TMG was studied formally by Alexander Birman and

Jeffrey Ullman Jeffrey David Ullman (born November 22, 1942) is an American computer scientist and the Stanford W. Ascherman Professor of Engineering, Emeritus, at Stanford University. His textbooks on compilers (various editions are popularly known as the dr ...

. The formal description of the algorithms was named ''TMG recognition scheme'' (or simply ''TS'').

References

External links

* * Compiling tools Parser generators Low-level programming languages {{Prog-lang-stub

See also

References

External links