1  /* Subroutines for bison
       2  
       3     Copyright (C) 1984, 1989, 2000-2002, 2007, 2009-2015, 2018-2021 Free
       4     Software Foundation, Inc.
       5  
       6     This file is part of Bison, the GNU Compiler Compiler.
       7  
       8     This program is free software: you can redistribute it and/or modify
       9     it under the terms of the GNU General Public License as published by
      10     the Free Software Foundation, either version 3 of the License, or
      11     (at your option) any later version.
      12  
      13     This program is distributed in the hope that it will be useful,
      14     but WITHOUT ANY WARRANTY; without even the implied warranty of
      15     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      16     GNU General Public License for more details.
      17  
      18     You should have received a copy of the GNU General Public License
      19     along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
      20  
      21  #ifndef CLOSURE_H_
      22  # define CLOSURE_H_
      23  
      24  # include "gram.h"
      25  
      26  /* Allocates the itemset and ruleset vectors, and precomputes useful
      27     data so that closure can be called.  n is the number of elements to
      28     allocate for itemset.  */
      29  
      30  void closure_new (int n);
      31  
      32  
      33  /* Given the kernel (aka core) of a state (a sorted vector of item indices
      34     ITEMS, of length N), set up RULESET and ITEMSET to indicate what
      35     rules could be run and which items could be accepted when those
      36     items are the active ones.  */
      37  
      38  void closure (item_index const *items, size_t n);
      39  
      40  
      41  /* Free ITEMSET, RULESET and internal data.  */
      42  
      43  void closure_free (void);
      44  
      45  
      46  /* ITEMSET is a sorted vector of item indices; NITEMSET is its size
      47     (actually, points to just beyond the end of the part of it that is
      48     significant).  CLOSURE places there the indices of all items which
      49     represent units of input that could arrive next.  */
      50  
      51  extern item_index *itemset;
      52  extern size_t nitemset;
      53  
      54  #endif /* !CLOSURE_H_ */