The original is 'lex', written in 1975 by Mike Lesk and Eric Schmidt.

Yes, that Eric Schmidt, CEO of Google.

1987 was the clone, 'flex' :-)

It did "compiling the regex into regular code, which can then be optimized by the compiler" before the C programming language as we know it was created. I think 'lex' was compiling regex to C before the C language even had 'struct' types, 'printf' or 'malloc'.