Re: Multiple lex scanners? How?

[Bob Proulx]

Nicolas Joly wrote:
> Bob Proulx wrote:
> > What is the best practice for organizing a program that includes
> > multiple lex generated scanners?
> 
> I encountered the same problem ... and made the following constructs
> that did the trick (at least for me).
> 
> AUTOMAKE_OPTIONS = subdir-objects
> 
> AM_YFLAGS = -d -p `basename $* | sed 's,y$$,,'`
> AM_LFLAGS = -s -P`basename $* | sed 's,l$$,,'` -olex.yy.c

That is very clever.  I like it.  The -P option solves the renames
completely but flex renames the output file but the -o solves that
problem.  Very nice!

In my case I might need to generate a mapping from filename to symbol
name (instead of your case using sed) because the legacy code I am
dealing with does not use the filenames for the symbol names.  In my
case the filenames are long and the symbols are short.  But I can deal
with that reasonably enough.

So for the mail archive my case might be:

  AM_LFLAGS = -s -P`basename $* | sed 's|ascscan|asc_|;s|gdsscan|gds_|'` 
-olex.yy.c

I expect that mapping to be very filename and symbol name specific.

> Hope this helps,

Very much so.  I think there might be room for improvement in some way
to make this easier but I am not sure what to suggest.

Thanks!
Bob