diff options
Diffstat (limited to 'libparser.c')
| -rw-r--r-- | libparser.c | 63 |
1 files changed, 50 insertions, 13 deletions
diff --git a/libparser.c b/libparser.c index 56ce703..eec9337 100644 --- a/libparser.c +++ b/libparser.c @@ -43,11 +43,17 @@ struct followup { /** * Set if and only if `.unit` is non-`NULL`: - * the - * index of the node + * the index of the node */ size_t unit_index; + /** + * Set if and only if `.unit` is non-`NULL`: + * the index of the node of the previous + * rejection, `SIZE_MAX` if none + */ + size_t previous_rejection; + /* -- or -- */ /** @@ -101,6 +107,12 @@ struct choice { size_t unit_index; /** + * The value `.previous_rejection` of the `ctx` + * argument `add_unit` was called with + */ + size_t previous_rejection; + + /** * Save state of the follow-up stack */ struct { @@ -202,6 +214,12 @@ struct context { } units; /** + * The index of the node of the previous + * rejection, `SIZE_MAX` if none + */ + size_t previous_rejection; + + /** * The text being parsed */ const char *data; @@ -296,10 +314,15 @@ print_state(struct context *ctx) ctx->choices.choices[i].position, sentence_type_string(ctx->choices.choices[i].sentence->type), ctx->choices.choices[i].rule); - if (ctx->choices.choices[i].choice == EXHAUSTED) { - fprintf(stderr, "choices EXHAUSTED\n"); + if (ctx->choices.choices[i].choice == EXHAUSTED) + fprintf(stderr, "choices EXHAUSTED; "); + else + fprintf(stderr, "using choice %zu; ", ctx->choices.choices[i].choice); + if (ctx->choices.choices[i].previous_rejection == SIZE_MAX) { + fprintf(stderr, "no rejection stored\n"); } else { - fprintf(stderr, "using choice %zu\n", ctx->choices.choices[i].choice); + fprintf(stderr, "previous rejection: %zu\n", + ctx->choices.choices[i].previous_rejection); } } @@ -309,13 +332,19 @@ print_state(struct context *ctx) if (IS_COMPLETION(ctx->followups.followups[i])) { unit = ctx->followups.followups[i].unit; sentence = unit->sentence; - fprintf(stderr, " Completion: unit %zu: %s: %s%s%s [%zu, %zu)\n", + fprintf(stderr, " Completion: unit %zu: %s: %s%s%s [%zu, %zu); ", ctx->followups.followups[i].unit_index, unit->rule, sentence_type_string(sentence->type), sentence->type == LIBPARSER_SENTENCE_TYPE_RULE ? " " : "", sentence->type == LIBPARSER_SENTENCE_TYPE_RULE ? sentence->rule.rule : "", unit->start, unit->end); + if (ctx->followups.followups[i].previous_rejection == SIZE_MAX) { + fprintf(stderr, "no rejection stored\n"); + } else { + fprintf(stderr, "previous rejection: %zu\n", + ctx->followups.followups[i].previous_rejection); + } } else { sentence = ctx->followups.followups[i].sentence; fprintf(stderr, " (%s, %s%s%s)\n", @@ -661,6 +690,7 @@ incomplete(const char *rule, const union libparser_sentence *sentence, size_t st } followup->unit = unit; followup->unit_index = ctx->units.count; + followup->previous_rejection = ctx->previous_rejection; #if PRINT_ACTIONS fprintf(stderr, "Pushing follow-up completion for unit %zu: %s: %s\n", @@ -724,6 +754,7 @@ braching(const char *rule, const union libparser_sentence *sentence, size_t star choice->rule = rule; choice->sentence = sentence; choice->unit_index = ctx->units.count; + choice->previous_rejection = ctx->previous_rejection; choice->followups.followups = NULL; choice->followups.count = ctx->followups.count; if (choice->followups.count) { @@ -741,13 +772,19 @@ braching(const char *rule, const union libparser_sentence *sentence, size_t star sentence_type_string(sentence->type), rule, start); } else { fprintf(stderr, "Revisiting branching point %zu at %zu in text for unit %zu: " - "%s: %s, at %zu in text; choice value: %zu\n", + "%s: %s, at %zu in text; choice value: %zu; ", ctx->choices.next, start, ctx->choices.choices[ctx->choices.next].unit_index, sentence_type_string(ctx->choices.choices[ctx->choices.next].sentence->type), ctx->choices.choices[ctx->choices.next].rule, ctx->choices.choices[ctx->choices.next].position, ctx->choices.choices[ctx->choices.next].choice); + if (ctx->choices.choices[ctx->choices.next].previous_rejection == SIZE_MAX) { + fprintf(stderr, "no rejection stored\n"); + } else { + fprintf(stderr, "previous rejection: %zu\n", + ctx->choices.choices[ctx->choices.next].previous_rejection); + } #endif } *choice_out = ctx->choices.choices[ctx->choices.next++].choice; @@ -842,6 +879,7 @@ add_unit(const char *rule, const union libparser_sentence *sentence, struct cont if (incomplete(NULL, sentence, start, ctx) || push(NULL, sentence->unary.sentence, ctx)) return -1; + ctx->previous_rejection = ctx->units.count - 1u; return 1; case LIBPARSER_SENTENCE_TYPE_RULE: @@ -1080,12 +1118,8 @@ __attribute__((__pure__)) static int choice_contains_rejection(struct context *ctx) { - /* TODO we should keep track of our rejections so we can do this in constant time */ - size_t i = ctx->choices.choices[ctx->choices.count - 1u].unit_index; - for (i += 1u; i < ctx->units.count; i++) - if (ctx->units.units[i]->sentence->type == LIBPARSER_SENTENCE_TYPE_REJECTION) - return 1; - return 0; + size_t i = ctx->choices.choices[ctx->choices.count - 1u].previous_rejection; + return ctx->previous_rejection != i; } @@ -1111,6 +1145,7 @@ libparser_parse_file(const struct libparser_rule *const rules[], const char *dat ctx.units.size = 0; ctx.units.count = 0; ctx.unit_pool = NULL; + ctx.previous_rejection = SIZE_MAX; ctx.data = data; ctx.length = length; ctx.position = 0; @@ -1203,6 +1238,7 @@ followup: fprintf(stderr, "Setting end of popped unit to %zu\n", ctx.position); #endif unit->end = ctx.position; + ctx.previous_rejection = ctx.followups.followups[i].previous_rejection; } else if (match) { rule = ctx.followups.followups[i].rule; sentence = ctx.followups.followups[i].sentence; @@ -1231,6 +1267,7 @@ followup: } ctx.choices.choices[i].choice++; ctx.position = ctx.choices.choices[i].position; + ctx.previous_rejection = ctx.choices.choices[i].previous_rejection; rule = ctx.choices.choices[i].rule; sentence = ctx.choices.choices[i].sentence; #if PRINT_ACTIONS |