FSCAN is a language for specifying the lexical analysis of programs written in any current programming language, including FORTRAN. This report describes the FSCAN language, a complier for the language, and an interpreter for the resulting object code. The interpreter object code forms an efficient lexical analyzer that takes as input a stream of characters and produces as output a stream of tokens (lexical units). The compiler and interpreter are designed for portability. Both are written in ANS FORTRAN (1966) supplemented by a small number of short machine dependent subroutines.
Clemm, Geoffrey M., "FSCAN Report and User's Manual ; CU-CS-166-79" (1979). Computer Science Technical Reports. 164.