projects / bison.git / blame
| Commit | Line | Data |
|---|---|---|
| c29240e7 | 1 | /* Subroutines for bison |
| 81ebdef9 PE |
2 | |
| 3 | Copyright (C) 1984, 1989, 2000, 2001, 2002 Free Software | |
| 4 | Foundation, Inc. | |
| c29240e7 AD |
5 | |
| 6 | This file is part of Bison, the GNU Compiler Compiler. | |
| 7 | ||
| 8 | Bison is free software; you can redistribute it and/or modify it | |
| 9 | under the terms of the GNU General Public License as published by | |
| 10 | the Free Software Foundation; either version 2, or (at your option) | |
| 11 | any later version. | |
| 12 | ||
| 13 | Bison is distributed in the hope that it will be useful, but | |
| 14 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 16 | General Public License for more details. | |
| 17 | ||
| 18 | You should have received a copy of the GNU General Public License | |
| 19 | along with Bison; see the file COPYING. If not, write to the Free | |
| 0fb669f9 PE |
20 | Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 21 | 02110-1301, USA. */ | |
| c29240e7 | 22 | |
| 340ef489 AD |
23 | #ifndef CLOSURE_H_ |
| 24 | # define CLOSURE_H_ | |
| c29240e7 | 25 | |
| 81ebdef9 PE |
26 | # include "gram.h" |
| 27 | ||
| c29240e7 AD |
28 | /* Allocates the itemset and ruleset vectors, and precomputes useful |
| 29 | data so that closure can be called. n is the number of elements to | |
| 30 | allocate for itemset. */ | |
| 31 | ||
| da2a7671 | 32 | void new_closure (unsigned int n); |
| c29240e7 AD |
33 | |
| 34 | ||
| b2872512 | 35 | /* Given the kernel (aka core) of a state (a vector of item numbers |
| 8b3df748 | 36 | ITEMS, of length N), set up RULESET and ITEMSET to indicate what |
| b2872512 AD |
37 | rules could be run and which items could be accepted when those |
| 38 | items are the active ones. | |
| c29240e7 | 39 | |
| 8b3df748 | 40 | RULESET contains a bit for each rule. CLOSURE sets the bits for |
| c29240e7 AD |
41 | all rules which could potentially describe the next input to be |
| 42 | read. | |
| 43 | ||
| b2872512 | 44 | ITEMSET is a vector of item numbers; NITEMSET is its size |
| 8b3df748 AD |
45 | (actually, points to just beyond the end of the part of it that is |
| 46 | significant). CLOSURE places there the indices of all items which | |
| b2872512 | 47 | represent units of input that could arrive next. */ |
| c29240e7 | 48 | |
| f6fbd3da | 49 | void closure (item_number *items, size_t n); |
| c29240e7 AD |
50 | |
| 51 | ||
| 8b3df748 | 52 | /* Frees ITEMSET, RULESET and internal data. */ |
| c29240e7 | 53 | |
| d33cb3ae | 54 | void free_closure (void); |
| 340ef489 | 55 | |
| 81ebdef9 | 56 | extern item_number *itemset; |
| f6fbd3da | 57 | extern size_t nritemset; |
| 340ef489 AD |
58 | |
| 59 | #endif /* !CLOSURE_H_ */ |