; Convert an fmsl-style grammar to yacc.  Here's the basic conversion process:
;
;   * For all multi-char sym lits of the form 'xxx', define token defs of the
;     form "%token Yxxx" in the defs section.
;
;   * Replace all multi-char tokens with their defined Yxxx token defs, leaving
;     single-char 'x' tokens as is.
;
;   * Convert '::=' or '->' rule separators to ':'.
;     
;   * More to come ...
;