How to generate parser from *.l and *.y files?

[kj]

I have input files for lex and yacc (tok.l and gram.y). I
could use lex and yacc to generate a parser from these files, but
the generated code would be C. Is there a way to directly generate
Perl code from these files?

(I'm aware of Parse::RecDescent, but the grammar in gram.y is
voluminous (the file is almost 1MB in size), and it would take me
forever to translate it to one that Parse::RecDescent can understand...
unless, of course, there is an automated means to perform such
translation.)

TIA!

kj