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handle charsets

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This commit is contained in:
Sven M. Hallberg 2013-06-12 16:38:50 +02:00
parent 41d4be4b84
commit 4b5a936667
1 changed files with 27 additions and 11 deletions
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38
src/backends/lalr.c
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@ -229,15 +229,33 @@ static HHashSet *closure(HCFGrammar *g, const HHashSet *items)
HCFChoice *sym = item->rhs[item->mark]; // symbol after mark
// if there is a non-terminal after the mark, follow it
// XXX: do we have to count HCF_CHARSET as nonterminal?
if(sym != NULL && sym->type == HCF_CHOICE) {
// NB: unlike LLk, we do consider HCF_CHARSET a non-terminal here
if(sym != NULL && (sym->type==HCF_CHOICE || sym->type==HCF_CHARSET)) {
// add items corresponding to the productions of sym
for(HCFSequence **p=sym->seq; *p; p++) {
HLRItem *it = h_lritem_new(arena, sym, (*p)->items, 0);
if(!h_hashset_present(ret, it)) {
h_hashset_put(ret, it);
h_slist_push(work, it);
if(sym->type == HCF_CHOICE) {
for(HCFSequence **p=sym->seq; *p; p++) {
HLRItem *it = h_lritem_new(arena, sym, (*p)->items, 0);
if(!h_hashset_present(ret, it)) {
h_hashset_put(ret, it);
h_slist_push(work, it);
}
}
} else { // HCF_CHARSET
for(unsigned int i=0; i<256; i++) {
if(charset_isset(sym->charset, i)) {
HCFChoice **rhs = h_arena_malloc(arena, 2 * sizeof(HCFChoice *));
rhs[0] = h_arena_malloc(arena, sizeof(HCFChoice));
rhs[0]->type = HCF_CHAR;
rhs[0]->chr = i;
rhs[1] = NULL;
HLRItem *it = h_lritem_new(arena, sym, rhs, 0);
h_hashset_put(ret, it);
// single-character item needs no further work
}
}
// if sym is a non-terminal, we need a reshape on it
// this seems as good a place as any to set it
sym->reshape = h_act_first;
}
// if sym derives epsilon, also advance over it
@ -615,8 +633,6 @@ h_lr_lookup(const HLRTable *table, size_t state, const HCFChoice *symbol)
}
}
// XXX also, what about charsets!?
HParseResult *h_lr_parse(HAllocator* mm__, const HParser* parser, HInputStream* stream)
{
HLRTable *table = parser->backend_data;
@ -884,7 +900,7 @@ int test_lalr(void)
*/
// XXX make LALR example
HParser *X = h_optional(h_ch('x'));
HParser *X = h_optional(h_in((uint8_t *)"rst", 3));
HParser *Y = h_sequence(h_ch('y'), h_ch('y'), NULL);
HParser *A = h_sequence(X, Y, h_ch('a'), NULL);
HParser *B = h_sequence(Y, h_ch('b'), NULL);
@ -921,7 +937,7 @@ int test_lalr(void)
h_pprint_lrtable(stdout, g, (HLRTable *)p->backend_data, 0);
printf("\n==== P A R S E R E S U L T ====\n");
HParseResult *res = h_parse(p, (uint8_t *)"xyya", 4);
HParseResult *res = h_parse(p, (uint8_t *)"syya", 4);
if(res)
h_pprint(stdout, res->ast, 0, 2);
else