While bf(flex)(1) only generates a file tt(lex.yy.cc), flc() generates several
files: several header files and a source file.  By default flc() generates a
class header file (tt(Scanner.h)), and internal header file (tt(Scanner.ih)),
a base class header file (tt(Scannerbase.h)), and the file tt(lex.cc)
containing the implementation of the required members of the tt(class
Scanner).  tt(Scannerbase.h) and tt(lex.cc) should not be edited: they are
overwritten whenever flc() is invoked. The other files (tt(Scanner.h) and
tt(Scanner.ih)) are generated only once, and can thereafter be modified by the
user (e.g., to add members to the tt(Scanner) class).

