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60 lines
1.9 KiB
C
60 lines
1.9 KiB
C
/* Subroutines for bison
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Copyright (C) 1984, 1989, 2000, 2001, 2002 Free Software
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Foundation, Inc.
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This file is part of Bison, the GNU Compiler Compiler.
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Bison is free software; you can redistribute it and/or modify it
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under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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Bison is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with Bison; see the file COPYING. If not, write to the Free
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Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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02110-1301, USA. */
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#ifndef CLOSURE_H_
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# define CLOSURE_H_
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# include "gram.h"
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/* Allocates the itemset and ruleset vectors, and precomputes useful
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data so that closure can be called. n is the number of elements to
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allocate for itemset. */
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void new_closure (unsigned int n);
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/* Given the kernel (aka core) of a state (a vector of item numbers
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ITEMS, of length N), set up RULESET and ITEMSET to indicate what
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rules could be run and which items could be accepted when those
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items are the active ones.
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RULESET contains a bit for each rule. CLOSURE sets the bits for
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all rules which could potentially describe the next input to be
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read.
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ITEMSET is a vector of item numbers; NITEMSET is its size
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(actually, points to just beyond the end of the part of it that is
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significant). CLOSURE places there the indices of all items which
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represent units of input that could arrive next. */
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void closure (item_number *items, size_t n);
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/* Frees ITEMSET, RULESET and internal data. */
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void free_closure (void);
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extern item_number *itemset;
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extern size_t nritemset;
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#endif /* !CLOSURE_H_ */
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