COGENT /COmpiler and GENeralized Translator/ programming system is a compiler whose input language enables a description of symbolic and linguistic manipulation algorithms. Primarily for use as a compiler-compiler, it is also applicable to algebraic manipulation, mechanical theorem proving, and heuristic programming

Reynolds, J. C.

English

NASA Technical Reports Server

November 1969	 Brief 69-10656 
.	
AEC-NASA TECH BRIEF 
AEC-NASA Tech Briefs describe innovations resulting from the research and development program 
of the U.S. AEC or from AEC-NASA interagency efforts. They are issued to encourage commercial 
application. Tech Briefs are published by NASA and may be purchased, at 15 cents each, from 
the Clearinghouse for Federal Scientific and Technical Information, Springfield, Virginia 22151. 
Cogent Programming Manual 
The problem: 
To achieve both the programming conciseness of a 
syntax-directed compiler system and the full generality 
of a recursive list-processing program. 
The solution: 
The COGENT (COmpiler and GENeralized Trans-
lator) programming system is a compiler whose input 
language is designed for the description of symbolic 
and linguistic manipulation algorithms. Although the 
system is intended primarily for use as a compiler-
compiler (a compiler that compiles other compilers), 
it is also applicable to such problem areas as algebraic 
manipulation, mechanical theorem-proving, and 
heuristic programming. 
An initial version of the COGENT system has been 
written for the Control Data-3600 computer. The 
manual (ref. I) is intended primarily to describe the 
input language for this system; operating procedures 
and details of the specific machine implementation are 
not discussed. 
How it's done: 
The COGENT system is a compiler that runs on the 
CD-3600 and translates COGENT language into 3600- 
assembly  language. When the system is used as a 
compiler-compiler, its output is a compiler that must 
run on the 3600 but which may translate an arbitrary 
input language into an arbitrary output language; 
e.g., numeric or symbolic code for any machine. 
Fundamentally a program compiled by COGENT 
is a list-processing program in which the list structures 
represent phrases of object language. The corres-
pondence between the strings of object language,
which appear externally on input-output media, and 
the list of structures, which represent these strings 
within the computer, is determined by the syntax of 
the object languages. Thus the COGENT language 
itself contains two types of structure: productions, 
which specify the syntax of the object languages; and 
generator definitions, which specify list-processing 
procedures called generators. The format of the 
generator definitions is designed to let the program-
mer think directly in terms of the phrases of language 
that are being manipulated, rather than of the list 
structures that actually represent these phrases. 
The main routine of a COGENT program is always 
a syntax-analyzer, which is compiled from the pro-
ductions describing the input object language. This 
analyzer reads character strings from the input 
medium and converts them into list structures. At 
certain points in this process, the analyzer calls a 
generatär to operate on the currently recognized 
sublist; the result of this generator then replaces the 
current sublist in the list being constructed. In addi-
tion to being called by the syntax-analyzer, generators 
may call each other and may call themselves recur-
sively. Ultimately, primitive (built-in) output-genera-
tors are called to decompose the list structures back 
into character strings and write these strings on the 
output medium. 
Reference: 
1. Reynolds, J. C.: COGENT Programming Manual. 
ANL-7022, Argonne National Laboratory, March 1965. 
Notes: 
I. This innovation may interest designers or manu-

facturers of computers or computer software. 
continued overleaft 
This document was prepared under the sponsorship of the Atomic 
Energy Commission and/or the National Aeronautics and Space 
Administration. Neither the United States Government nor any per-
son acting on behalf of the United States Government assumes any
liability resulting from the use of the information contained in this 
document, or warrants that the use of any information, apparatus, 
method, or process disclosed in this document may not infringe pri-
vately owned rights.
https://ntrs.nasa.gov/search.jsp?R=19690000593 2020-03-16T18:29:12+00:00Z
2. Inquiries concerning this innovation may be di-
rected to: 
Office of Industrial Cooperation 
Argonne National Laboratory 
9700 South Cass Avenue 
Argonne, Illinois 60439 
Reference: B69-10656 
Source: J. C. Reynolds
Mathematics Division
(ARG-10463)
Patent status: 
Inquiries concerning rights for commercial use of 
this innovation may be made to: 
Mr. George H. Lee, Chief 
Chicago Patent Group 
U.S. Atomic Energy Commission 
Chicago Operations Office 
9800 South Cass Avenue 
Argonne, Illinois 60439
. 
. 
Brief 69-10656	 Category 06


COGENT programming manual

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