From 67e5b2fee0e4ceff7fab9375065e737eda12dfe0 Mon Sep 17 00:00:00 2001
From: "Sven M. Hallberg" <pesco@khjk.org>
Date: Fri, 7 Jun 2013 16:30:16 +0200
Subject: [PATCH] add DFA pretty-printer
---
src/backends/lalr.c | 99 +++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 95 insertions(+), 4 deletions(-)
diff --git a/src/backends/lalr.c b/src/backends/lalr.c
index 509f76d2..15236f5e 100644
--- a/src/backends/lalr.c
+++ b/src/backends/lalr.c
@@ -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);
--
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