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add DFA pretty-printer

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This commit is contained in:
Sven M. Hallberg 2013-06-07 16:30:16 +02:00
parent 373a7aef94
commit 67e5b2fee0
1 changed files with 95 additions and 4 deletions
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99
src/backends/lalr.c
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@ -317,6 +317,93 @@ HParseResult *h_lr_parse(HAllocator* mm__, const HParser* parser, HInputStream*
/* Pretty-printers */
void h_pprint_lritem(FILE *f, const HCFGrammar *g, const HLRItem *item)
{
h_pprint_symbol(f, g, item->lhs);
fputs(" ->", f);
HCFChoice **x = item->rhs;
HCFChoice **mark = item->rhs + item->mark;
if(*x == NULL) {
fputs("\"\"", f);
} else {
while(*x) {
if(x == mark)
fputc('.', f);
else
fputc(' ', f);
if((*x)->type == HCF_CHAR) {
// condense character strings
fputc('"', f);
h_pprint_char(f, (*x)->chr);
for(x++; *x; x++) {
if(x == mark)
break;
if((*x)->type != HCF_CHAR)
break;
h_pprint_char(f, (*x)->chr);
}
fputc('"', f);
} else {
h_pprint_symbol(f, g, *x);
x++;
}
}
if(x == mark)
fputs(".", f);
}
}
void h_pprint_lrstate(FILE *f, const HCFGrammar *g,
const HLRState *state, unsigned int indent)
{
bool first = true;
const HHashTable *ht = state;
for(size_t i=0; i < ht->capacity; i++) {
for(HHashTableEntry *hte = &ht->contents[i]; hte; hte = hte->next) {
if(hte->key == NULL)
continue;
const HLRItem *item = hte->key;
if(!first)
for(unsigned int i=0; i<indent; i++) fputc(' ', f);
first = false;
h_pprint_lritem(f, g, item);
fputc('\n', f);
}
}
}
void pprint_transition(FILE *f, const HCFGrammar *g, const HLRTransition *t)
{
fputs("-", f);
h_pprint_symbol(f, g, t->symbol);
fprintf(f, "->%lu", t->to);
}
void h_pprint_lrdfa(FILE *f, const HCFGrammar *g,
const HLRDFA *dfa, unsigned int indent)
{
for(size_t i=0; i<dfa->nstates; i++) {
unsigned int indent2 = indent + fprintf(f, "%4lu: ", i);
h_pprint_lrstate(f, g, dfa->states[i], indent2);
for(HSlistNode *x = dfa->transitions->head; x; x = x->next) {
const HLRTransition *t = x->elem;
if(t->from == i) {
for(unsigned int i=0; i<indent2-2; i++) fputc(' ', f);
pprint_transition(f, g, t);
fputc('\n', f);
}
}
}
}
HParserBackendVTable h__lalr_backend_vtable = {
.compile = h_lalr_compile,
@ -346,6 +433,7 @@ int test_lalr(void)
HParser *B = h_sequence(Y, h_ch('b'), NULL);
HParser *p = h_choice(A, B, NULL);
printf("\n==== G R A M M A R ====\n");
HCFGrammar *g = h_cfgrammar(&system_allocator, p);
if(g == NULL) {
fprintf(stderr, "h_cfgrammar failed\n");
@ -353,18 +441,21 @@ int test_lalr(void)
}
h_pprint_grammar(stdout, g, 0);
printf("\n==== D F A ====\n");
HLRDFA *dfa = h_lalr_dfa(g);
if(dfa) {
// print states of the LR(0) automaton
}
if(dfa)
h_pprint_lrdfa(stdout, g, dfa, 0);
else
fprintf(stderr, "h_lalr_dfa failed\n");
printf("\n==== L A L R T A B L E ====\n");
if(h_compile(p, PB_LALR, NULL)) {
fprintf(stderr, "does not compile\n");
return 2;
}
// print LALR(1) table
printf("\n==== P A R S E R E S U L T ====\n");
HParseResult *res = h_parse(p, (uint8_t *)"xyya", 4);
if(res)
h_pprint(stdout, res->ast, 0, 2);