Re: The making of compilers

[dewar@gnat.com (Robert Dewar)]

Keith Thompson <kst@cts.com> wrote in message news:<yecelj5c7uh.fsf@king.cts.com>...
> I would have thought that Cobol was a poor language for
> implementing a compiler, but Robert Dewar and others 
> apparently did just that with Realia Cobol.

My guess is that Keith is not a COBOL expert :-) Seriously
usually this kind of opinion comes from people who do not
know COBOL well. COBOL is a general purpose language with
many attractive features, and is perfectly suitable for
writing compilers.

In our case, one of the really big advantages in writing
the COBOL compiler in COBOL was speed, the Realia COBOL
compiler is far far faster than other compilers around
for the PC. To give an idea of the speed, on a 25MHz
386, the compiler (about 120K Sloc) would bootstrap in
under two minutes. Of course on a modern fast PC, running
perhaps 40 times faster, that should be down to well
under 10 seconds (I have not run it recently). That kind
of speed is welcome when developing large programs such
as a compiler :-)

Robert Dewar