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/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* $URL$
* $Id$
*
*/
/* Functionality to transform the context-free SCI grammar rules into
** strict Greibach normal form (strict GNF), and to test SCI input against
** that grammar, writing an appropriate node tree if successful.
*/
#include "sci/tools.h"
#include "sci/vocabulary.h"
#include "sci/console.h"
namespace Sci {
#define TOKEN_OPAREN 0xff000000
#define TOKEN_CPAREN 0xfe000000
#define TOKEN_TERMINAL_CLASS 0x10000
#define TOKEN_TERMINAL_GROUP 0x20000
#define TOKEN_STUFFING_WORD 0x40000
#define TOKEN_NON_NT (TOKEN_OPAREN | TOKEN_TERMINAL_CLASS | TOKEN_TERMINAL_GROUP | TOKEN_STUFFING_WORD)
#define TOKEN_TERMINAL (TOKEN_TERMINAL_CLASS | TOKEN_TERMINAL_GROUP)
static int _allocd_rules = 0; // FIXME: Avoid non-const global vars
int getAllocatedRulesCount() { return _allocd_rules; }
static void vocab_print_rule(parse_rule_t *rule) {
int i;
int wspace = 0;
if (!rule) {
sciprintf("NULL rule");
return;
}
sciprintf("[%03x] -> ", rule->id);
if (!rule->length)
sciprintf("e");
for (i = 0; i < rule->length; i++) {
uint token = rule->data[i];
if (token == TOKEN_OPAREN) {
if (i == rule->first_special)
sciprintf("_");
sciprintf("(");
wspace = 0;
} else if (token == TOKEN_CPAREN) {
if (i == rule->first_special)
sciprintf("_");
sciprintf(")");
wspace = 0;
} else {
if (wspace)
sciprintf(" ");
if (i == rule->first_special)
sciprintf("_");
if (token & TOKEN_TERMINAL_CLASS)
sciprintf("C(%04x)", token & 0xffff);
else if (token & TOKEN_TERMINAL_GROUP)
sciprintf("G(%04x)", token & 0xffff);
else if (token & TOKEN_STUFFING_WORD)
sciprintf("%03x", token & 0xffff);
else
sciprintf("[%03x]", token); /* non-terminal */
wspace = 1;
}
if (i == rule->first_special)
sciprintf("_");
}
sciprintf(" [%d specials]", rule->specials_nr);
}
static void _vfree(parse_rule_t *rule) {
free(rule);
--_allocd_rules;
rule = NULL;
}
static parse_rule_t *_vdup(parse_rule_t *a) {
parse_rule_t *rule = (parse_rule_t*)malloc(sizeof(int) * (a->length + 4));
rule->id = a->id;
rule->length = a->length;
rule->specials_nr = a->specials_nr;
rule->first_special = a->first_special;
++_allocd_rules;
memcpy(rule->data, a->data, sizeof(int) * a->length);
return rule;
}
static parse_rule_t *_vinsert(parse_rule_t *turkey, parse_rule_t *stuffing) {
int firstnt = turkey->first_special;
parse_rule_t *rule;
while ((firstnt < turkey->length) && (turkey->data[firstnt] & TOKEN_NON_NT))
firstnt++;
if ((firstnt == turkey->length) || (turkey->data[firstnt] != stuffing->id))
return NULL;
rule = (parse_rule_t*)malloc(sizeof(int) * (turkey->length - 1 + stuffing->length + 4));
rule->id = turkey->id;
rule->specials_nr = turkey->specials_nr + stuffing->specials_nr - 1;
rule->first_special = firstnt + stuffing->first_special;
rule->length = turkey->length - 1 + stuffing->length;
++_allocd_rules;
if (firstnt > 0)
memcpy(rule->data, turkey->data, sizeof(int) * firstnt);
memcpy(&(rule->data[firstnt]), stuffing->data, sizeof(int) * stuffing->length);
if (firstnt < turkey->length - 1)
memcpy(&(rule->data[firstnt + stuffing->length]), &(turkey->data[firstnt + 1]), sizeof(int) * (turkey->length - firstnt - 1));
return rule;
}
static parse_rule_t *_vbuild_rule(const parse_tree_branch_t *branch) {
parse_rule_t *rule;
int tokens = 0, tokenpos = 0, i;
while (tokenpos < 10 && branch->data[tokenpos]) {
int type = branch->data[tokenpos];
tokenpos += 2;
if ((type == VOCAB_TREE_NODE_COMPARE_TYPE) || (type == VOCAB_TREE_NODE_COMPARE_GROUP) || (type == VOCAB_TREE_NODE_FORCE_STORAGE))
++tokens;
else if (type > VOCAB_TREE_NODE_LAST_WORD_STORAGE)
tokens += 5;
else
return NULL; // invalid
}
rule = (parse_rule_t*)malloc(sizeof(int) * (4 + tokens));
++_allocd_rules;
rule->id = branch->id;
rule->specials_nr = tokenpos >> 1;
rule->length = tokens;
rule->first_special = 0;
tokens = 0;
for (i = 0; i < tokenpos; i += 2) {
int type = branch->data[i];
int value = branch->data[i + 1];
if (type == VOCAB_TREE_NODE_COMPARE_TYPE)
rule->data[tokens++] = value | TOKEN_TERMINAL_CLASS;
else if (type == VOCAB_TREE_NODE_COMPARE_GROUP)
rule->data[tokens++] = value | TOKEN_TERMINAL_GROUP;
else if (type == VOCAB_TREE_NODE_FORCE_STORAGE)
rule->data[tokens++] = value | TOKEN_STUFFING_WORD;
else { // normal inductive rule
rule->data[tokens++] = TOKEN_OPAREN;
rule->data[tokens++] = type | TOKEN_STUFFING_WORD;
rule->data[tokens++] = value | TOKEN_STUFFING_WORD;
if (i == 0)
rule->first_special = tokens;
rule->data[tokens++] = value; // The non-terminal
rule->data[tokens++] = TOKEN_CPAREN;
}
}
return rule;
}
static parse_rule_t *_vsatisfy_rule(parse_rule_t *rule, const ResultWord &input) {
int dep;
if (!rule->specials_nr)
return NULL;
dep = rule->data[rule->first_special];
if (((dep & TOKEN_TERMINAL_CLASS) && ((dep & 0xffff) & input._class)) ||
((dep & TOKEN_TERMINAL_GROUP) && ((dep & 0xffff) & input._group))) {
parse_rule_t *retval = (parse_rule_t*)malloc(sizeof(int) * (4 + rule->length));
++_allocd_rules;
retval->id = rule->id;
retval->specials_nr = rule->specials_nr - 1;
retval->length = rule->length;
memcpy(retval->data, rule->data, sizeof(int) * retval->length);
retval->data[rule->first_special] = TOKEN_STUFFING_WORD | input._group;
retval->first_special = 0;
if (retval->specials_nr) { // find first special, if it exists
int tmp, i = rule->first_special;
while ((i < rule->length)&& ((tmp = retval->data[i]) & TOKEN_NON_NT) && !(tmp & TOKEN_TERMINAL))
++i;
if (i < rule->length)
retval->first_special = i;
}
return retval;
} else
return NULL;
}
void Vocabulary::freeRuleList(parse_rule_list_t *list) {
if (list) {
_vfree(list->rule);
freeRuleList(list->next); // Yep, this is slow and memory-intensive.
free(list);
}
}
static int _rules_equal_p(parse_rule_t *r1, parse_rule_t *r2) {
if ((r1->id != r2->id) || (r1->length != r2->length) || (r1->first_special != r2->first_special))
return 0;
return !(memcmp(r1->data, r2->data, sizeof(int) * r1->length));
}
static parse_rule_list_t *_vocab_add_rule(parse_rule_list_t *list, parse_rule_t *rule) {
parse_rule_list_t *new_elem;
int term;
if (!rule)
return list;
new_elem = (parse_rule_list_t*)malloc(sizeof(parse_rule_list_t));
term = rule->data[rule->first_special];
new_elem->rule = rule;
new_elem->next = NULL;
new_elem->terminal = term = ((term & TOKEN_TERMINAL) ? term : 0);
if (!list)
return new_elem;
else {
/* if (term < list->terminal) {
new_elem->next = list;
return new_elem;
} else {*/
parse_rule_list_t *seeker = list;
while (seeker->next/* && seeker->next->terminal <= term*/) {
if (seeker->next->terminal == term) {
if (_rules_equal_p(seeker->next->rule, rule)) {
_vfree(rule);
free(new_elem);
return list; // No duplicate rules
}
}
seeker = seeker->next;
}
new_elem->next = seeker->next;
seeker->next = new_elem;
return list;
}
}
static void _vprl(parse_rule_list_t *list, int pos) {
if (list) {
sciprintf("R%03d: ", pos);
vocab_print_rule(list->rule);
sciprintf("\n");
_vprl(list->next, pos + 1);
} else {
sciprintf("%d rules total.\n", pos);
}
}
void vocab_print_rule_list(parse_rule_list_t *list) {
_vprl(list, 0);
}
static parse_rule_list_t *_vocab_split_rule_list(parse_rule_list_t *list) {
if (!list->next || (list->next->terminal)) {
parse_rule_list_t *tmp = list->next;
list->next = NULL;
return tmp;
} else
return _vocab_split_rule_list(list->next);
}
static void _vocab_free_empty_rule_list(parse_rule_list_t *list) {
if (list->next)
_vocab_free_empty_rule_list(list->next);
free(list);
}
static parse_rule_list_t *_vocab_merge_rule_lists(parse_rule_list_t *l1, parse_rule_list_t *l2) {
parse_rule_list_t *retval = l1, *seeker = l2;
while (seeker) {
retval = _vocab_add_rule(retval, seeker->rule);
seeker = seeker->next;
}
_vocab_free_empty_rule_list(l2);
return retval;
}
static int _vocab_rule_list_length(parse_rule_list_t *list) {
return ((list) ? _vocab_rule_list_length(list->next) + 1 : 0);
}
static parse_rule_list_t *_vocab_clone_rule_list_by_id(parse_rule_list_t *list, int id) {
parse_rule_list_t *result = NULL;
parse_rule_list_t *seeker = list;
while (seeker) {
if (seeker->rule->id == id) {
result = _vocab_add_rule(result, _vdup(seeker->rule));
}
seeker = seeker->next;
}
return result;
}
parse_rule_list_t *Vocabulary::buildGNF(bool verbose) {
int iterations = 0;
int last_termrules, termrules = 0;
int ntrules_nr;
parse_rule_list_t *ntlist = NULL;
parse_rule_list_t *tlist, *new_tlist;
Sci::Console *con = ((SciEngine *)g_engine)->_console;
for (uint i = 1; i < _parserBranches.size(); i++) { // branch rule 0 is treated specially
parse_rule_t *rule = _vbuild_rule(&_parserBranches[i]);
if (!rule)
return NULL;
ntlist = _vocab_add_rule(ntlist, rule);
}
tlist = _vocab_split_rule_list(ntlist);
ntrules_nr = _vocab_rule_list_length(ntlist);
if (verbose)
con->DebugPrintf("Starting with %d rules\n", ntrules_nr);
new_tlist = tlist;
tlist = NULL;
do {
parse_rule_list_t *new_new_tlist = NULL;
parse_rule_list_t *ntseeker, *tseeker;
last_termrules = termrules;
ntseeker = ntlist;
while (ntseeker) {
tseeker = new_tlist;
while (tseeker) {
parse_rule_t *newrule = _vinsert(ntseeker->rule, tseeker->rule);
if (newrule)
new_new_tlist = _vocab_add_rule(new_new_tlist, newrule);
tseeker = tseeker->next;
}
ntseeker = ntseeker->next;
}
tlist = _vocab_merge_rule_lists(tlist, new_tlist);
new_tlist = new_new_tlist;
termrules = _vocab_rule_list_length(new_new_tlist);
if (verbose)
con->DebugPrintf("After iteration #%d: %d new term rules\n", ++iterations, termrules);
} while (termrules && (iterations < 30));
freeRuleList(ntlist);
if (verbose) {
con->DebugPrintf("\nGNF rules:\n");
vocab_print_rule_list(tlist);
con->DebugPrintf("%d allocd rules\n", getAllocatedRulesCount());
con->DebugPrintf("Freeing rule list...\n");
freeRuleList(tlist);
return NULL;
}
return tlist;
}
static int _vbpt_pareno(parse_tree_node_t *nodes, int *pos, int base) {
// Opens parentheses
nodes[base].content.branches[0] = (*pos) + 1;
nodes[++(*pos)].type = PARSE_TREE_NODE_BRANCH;
nodes[*pos].content.branches[0] = 0;
nodes[*pos].content.branches[1] = 0;
return *pos;
}
static int _vbpt_parenc(parse_tree_node_t *nodes, int *pos, int paren) {
// Closes parentheses for appending
nodes[paren].content.branches[1] = ++(*pos);
nodes[*pos].type = PARSE_TREE_NODE_BRANCH;
nodes[*pos].content.branches[0] = 0;
nodes[*pos].content.branches[1] = 0;
return *pos;
}
static int _vbpt_append(parse_tree_node_t *nodes, int *pos, int base, int value) {
// writes one value to an existing base node and creates a successor node for writing
nodes[base].content.branches[0] = ++(*pos);
nodes[*pos].type = PARSE_TREE_NODE_LEAF;
nodes[*pos].content.value = value;
nodes[base].content.branches[1] = ++(*pos);
nodes[*pos].type = PARSE_TREE_NODE_BRANCH;
nodes[*pos].content.branches[0] = 0;
nodes[*pos].content.branches[1] = 0;
return *pos;
}
static int _vbpt_terminate(parse_tree_node_t *nodes, int *pos, int base, int value) {
// Terminates, overwriting a nextwrite forknode
nodes[base].type = PARSE_TREE_NODE_LEAF;
nodes[base].content.value = value;
return *pos;
}
static int _vbpt_write_subexpression(parse_tree_node_t *nodes, int *pos, parse_rule_t *rule, int rulepos, int writepos) {
uint token;
while ((token = ((rulepos < rule->length) ? rule->data[rulepos++] : TOKEN_CPAREN)) != TOKEN_CPAREN) {
uint nexttoken = (rulepos < rule->length) ? rule->data[rulepos] : TOKEN_CPAREN;
if (token == TOKEN_OPAREN) {
int wpold;
int writepos2 = _vbpt_pareno(nodes, pos, wpold = writepos);
rulepos = _vbpt_write_subexpression(nodes, pos, rule, rulepos, writepos2);
nexttoken = (rulepos < rule->length) ? rule->data[rulepos] : TOKEN_CPAREN;
if (nexttoken != TOKEN_CPAREN)
writepos = _vbpt_parenc(nodes, pos, wpold);
} else if (token & TOKEN_STUFFING_WORD) {
if (nexttoken == TOKEN_CPAREN)
writepos = _vbpt_terminate(nodes, pos, writepos, token & 0xffff);
else
writepos = _vbpt_append(nodes, pos, writepos, token & 0xffff);
} else {
sciprintf("\nError in parser (grammar.cpp, _vbpt_write_subexpression()): Rule data broken in rule ");
vocab_print_rule(rule);
sciprintf(", at token position %d\n", *pos);
return rulepos;
}
}
return rulepos;
}
int Vocabulary::parseGNF(parse_tree_node_t *nodes, const ResultWordList &words, bool verbose) {
Sci::Console *con = ((SciEngine *)g_engine)->_console;
// Get the start rules:
parse_rule_list_t *work = _vocab_clone_rule_list_by_id(_parserRules, _parserBranches[0].data[1]);
parse_rule_list_t *results = NULL;
int word = 0;
const int words_nr = words.size();
ResultWordList::const_iterator word_iter = words.begin();
for (word_iter = words.begin(); word_iter != words.end(); ++word_iter, ++word) {
parse_rule_list_t *new_work = NULL;
parse_rule_list_t *reduced_rules = NULL;
parse_rule_list_t *seeker, *subseeker;
if (verbose)
con->DebugPrintf("Adding word %d...\n", word);
seeker = work;
while (seeker) {
if (seeker->rule->specials_nr <= (words_nr - word))
reduced_rules = _vocab_add_rule(reduced_rules, _vsatisfy_rule(seeker->rule, *word_iter));
seeker = seeker->next;
}
if (reduced_rules == NULL) {
freeRuleList(work);
if (verbose)
con->DebugPrintf("No results.\n");
return 1;
}
freeRuleList(work);
if (word + 1 < words_nr) {
seeker = reduced_rules;
while (seeker) {
if (seeker->rule->specials_nr) {
int my_id = seeker->rule->data[seeker->rule->first_special];
subseeker = _parserRules;
while (subseeker) {
if (subseeker->rule->id == my_id)
new_work = _vocab_add_rule(new_work, _vinsert(seeker->rule, subseeker->rule));
subseeker = subseeker->next;
}
}
seeker = seeker->next;
}
freeRuleList(reduced_rules);
} else // last word
new_work = reduced_rules;
work = new_work;
if (verbose)
con->DebugPrintf("Now at %d candidates\n", _vocab_rule_list_length(work));
if (work == NULL) {
if (verbose)
con->DebugPrintf("No results.\n");
return 1;
}
}
results = work;
if (verbose) {
con->DebugPrintf("All results (excluding the surrounding '(141 %03x' and ')'):\n", _parserBranches[0].id);
vocab_print_rule_list(results);
con->DebugPrintf("\n");
}
// now use the first result
{
int temp, pos;
nodes[0].type = PARSE_TREE_NODE_BRANCH;
nodes[0].content.branches[0] = 1;
nodes[0].content.branches[1] = 2;
nodes[1].type = PARSE_TREE_NODE_LEAF;
nodes[1].content.value = 0x141;
nodes[2].type = PARSE_TREE_NODE_BRANCH;
nodes[2].content.branches[0] = 0;
nodes[2].content.branches[1] = 0;
pos = 2;
temp = _vbpt_append(nodes, &pos, 2, _parserBranches[0].id);
//_vbpt_write_subexpression(nodes, &pos, results[_vocab_rule_list_length(results)].rule, 0, temp);
_vbpt_write_subexpression(nodes, &pos, results->rule, 0, temp);
}
freeRuleList(results);
return 0;
}
} // End of namespace Sci
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