#ifndef grr_bypass_H
#define grr_bypass_H

/* grr_bypass.h - procedures for bypassing superfluous internal symbols */
/* Last edited on 2024-12-21 11:50:04 by stolfi */

#include <string.h>
#include <stdlib.h>
#include <assert.h>
#include <stdio.h>

#include <vec.h>

#include <grr_grammar.h>

Grammar_t *grr_remove_superfluous_symbols(Grammar_t *G);
/* Returns a new grammar obtained from {G} by replacing 
  some internal symbols by their definitions.  E.g., 
  if the input grammar is {X -> $A, Y -> Z $B, $A -> W}
  returns {X -> W, Y -> Z W}.  
  
  Internal symbols are identified by the first letter of their name
  being '$' or '*'. Note that "F:*X" is not considered internal. A
  symbol /may/ be replaced if that would reduce the size of the
  grammar.
  
  In particular, an internal symbol that has at most one defining rule
  or at most one use in the RHS will be replaced. The result is not
  guaranteed to be minimal, and depends on the order in which symbols
  and rules are examined.
  
  A symbol cannot be replaced if it occurs on both sides of the '->'
  in the same rule, or if it has a binary definition and is used in
  another binary rule. */

#endif