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void alert_parse(struct state *state) { }
int disambiguator(struct state *old, struct state *new) {
// fprintf(stderr, "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n");
// print_parse_tree(old, 0, stderr);
// print_parse_tree(new, 0, stderr);
// fprintf(stderr, "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n");
if (old->n_poisoned < new->n_poisoned) return 0;
if (new->n_poisoned < old->n_poisoned) return 1;
// Prefer the earlier parsings in the grammar when two entirely different
// productions are taken.
if (old->production_id != new->production_id)
return (old->production_id < new->production_id) ? 0 : 1;
// If they're the same production ...
prod_id_t prod = old->production_id;
if (PRODUCTION_ID_TO_SYMBOL[prod] == START_SYMBOL
&& PRODUCTION_ID_TO_PRODUCTION[prod][1] != DONE_SYMBOL) {
struct token *old_tok = find_token(old, 1),
*new_tok = find_token(new, 1);
if (old_tok < new_tok) return 0;
else if (old_tok > new_tok) return 1;
}
if (PRODUCTION_ID_TO_PRODUCTION[prod][0] == SYMBOL_ERROR && PRODUCTION_ID_TO_PRODUCTION[prod][1] != DONE_SYMBOL) {
struct token *old_tok = find_token(old, 1),
*new_tok = find_token(new, 1);
if (old_tok < new_tok) return 0;
else if (old_tok > new_tok) return 1;
} else if (PRODUCTION_ID_TO_PRODUCTION[prod][1] == SYMBOL_ERROR) {
struct token *old_tok = find_token(old, 1),
*new_tok = find_token(new, 1);
if (old_tok < new_tok) return 1;
else if (old_tok > new_tok) return 0;
} else if (PRODUCTION_ID_TO_SYMBOL[prod] == SYMBOL_EXPR) {
if (PRODUCTION_ID_TO_PRODUCTION[prod][1] == SYMBOL_OP) {
struct token *old_tok = find_token(old, 1),
*new_tok = find_token(new, 1);
char *old_s = old_tok->string, *new_s = new_tok->string;
const char *precedence[] = {".", "->", "*", "/", "%", "+", "-",
"<<", ">>", "<", "<=", ">", ">=", "==", "!=", "&", "|", "&&",
"||", "=", "+=", "-=", "*=", "/=", "%=", "<<=", ">>=", "&=",
"^=", "|=", ",", ":", 0};
if (strcmp(old_s, new_s)) {
for (const char **p = precedence; *p; p++) {
if (!strcmp(old_s, *p)) {
return 1;
} else if (!strcmp(new_s, *p)) {
return 0;
}
}
fprintf(stderr, "ERROR: didn't find operator '%s'\n", old_s);
exit(1);
} else {
if (old_tok < new_tok) return 1;
else if (old_tok > new_tok) return 0;
}
}
}
// Generally speaking, we want left associativity to avoid long chains of
// completions.
struct token *old_tok = find_token(old, 1),
*new_tok = find_token(new, 1);
if (old_tok < new_tok) return 1;
else if (old_tok > new_tok) return 0;
fprintf(stderr, "TOTALLY UNKNOWN!\n");
fprintf(stderr, "~~~~~~~~~~~~~~~~~~~~~\n");
pprint_state(old);
// print_parse_tree(old, 0, stderr);
fprintf(stderr, "~~~~~~~~~~~~~~~~~~~~~\n");
pprint_state(new);
// print_parse_tree(new, 0, stderr);
fprintf(stderr, "~~~~~~~~~~~~~~~~~~~~~\n");
exit(1);
return 2;
}
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