now the robust parser is purely top-down and the meta rules compete on a fair basis with the grammar rules

src/runtime/c/pgf/data.c

@@ -3,6 +3,7 @@
 #include <gu/type.h>
 #include <gu/variant.h>
 #include <gu/assert.h>
+#include <math.h>
 
 bool 
 pgf_tokens_equal(PgfTokens t1, PgfTokens t2)
@@ -184,6 +185,12 @@ GU_DEFINE_TYPE(
 	GU_MEMBER(PgfCatFun, prob, double),
 	GU_MEMBER(PgfCatFun, fun, PgfCId));
 
+static float inf_float = INFINITY;
+
+GU_DEFINE_TYPE(PgfMetaChildMap, GuMap,
+		       gu_type(PgfCat), NULL,
+		       gu_type(float), &inf_float);
+
 GU_DEFINE_TYPE(
 	PgfCat, struct, 
 	GU_MEMBER(PgfCat, context, PgfHypos),

src/runtime/c/pgf/data.h

@@ -145,11 +145,16 @@ struct PgfCatFun {
 	PgfCId fun;
 };
 
+typedef GuMap PgfMetaChildMap;
+extern GU_DECLARE_TYPE(PgfMetaChildMap, GuMap);
+
 struct PgfCat {
 	// TODO: Add cid here
 	PgfHypos context;
 
 	float meta_prob;
+	float meta_token_prob;
+	PgfMetaChildMap* meta_child_probs;
 
 	GuLength n_functions;
 	PgfCatFun functions[]; // XXX: resolve to PgfFunDecl*?

src/runtime/c/pgf/parser.c

@@ -492,7 +492,9 @@ pgf_item_set_curr_symbol(PgfItem* item, GuPool* pool)
 
 static PgfItem*
 pgf_new_item(int pos, PgfCCat* ccat, size_t lin_idx,
-             PgfProduction prod, PgfItemBuf* conts, GuPool* pool)
+             PgfProduction prod, PgfItemBuf* conts, 
+             float delta_prob,
+             GuPool* pool)
 {
     PgfItemBase* base = gu_new(PgfItemBase, pool);
 	base->ccat = ccat;
@@ -557,6 +559,7 @@ pgf_new_item(int pos, PgfCCat* ccat, size_t lin_idx,
 				best_cont->inside_prob-ccat->viterbi_prob+
 				best_cont->outside_prob;
 	}
+	item->outside_prob += delta_prob;
 
 	pgf_item_set_curr_symbol(item, pool);
 	return item;
@@ -650,7 +653,12 @@ pgf_parsing_combine(PgfParseState* before, PgfParseState* after,
 			   nargs * sizeof(PgfPArg));
 		gu_seq_set(item->args, PgfPArg, nargs,
 		     ((PgfPArg) { .hypos = NULL, .ccat = cat }));
-		item->inside_prob += cat->viterbi_prob;
+
+		PgfCIdMap* meta_child_probs =
+			item->base->ccat->cnccat->abscat->meta_child_probs;
+		item->inside_prob += 
+			cat->viterbi_prob+
+			gu_map_get(meta_child_probs, cat->cnccat->abscat, float);
 
 		PgfSymbol prev = item->curr_sym;
 		PgfSymbolCat* scat = (PgfSymbolCat*)
@@ -673,10 +681,11 @@ pgf_parsing_combine(PgfParseState* before, PgfParseState* after,
 static void
 pgf_parsing_production(PgfParseState* state,
                        PgfCCat* ccat, size_t lin_idx,
-                       PgfProduction prod, PgfItemBuf* conts)
+                       PgfProduction prod, PgfItemBuf* conts,
+                       float delta_prob)
 {
 	PgfItem* item =
-        pgf_new_item(state->offset, ccat, lin_idx, prod, conts, state->pool);
+        pgf_new_item(state->offset, ccat, lin_idx, prod, conts, delta_prob, state->pool);
     gu_buf_heap_push(state->agenda, &pgf_item_prob_order, &item);
 }
 
@@ -798,7 +807,7 @@ pgf_parsing_complete(PgfParseState* before, PgfParseState* after,
 			 * i.e. process it. */
 			if (conts2) {
 				pgf_parsing_production(before, cat, i,
-							   prod, conts2);
+							   prod, conts2, 0);
 			}
 		}
 
@@ -818,7 +827,7 @@ pgf_parsing_complete(PgfParseState* before, PgfParseState* after,
 				 * i.e. process it. */
 				if (conts2) {
 					pgf_parsing_production(state, cat, i,
-								   prod, conts2);
+								   prod, conts2, 0);
 				}
 			}
 
@@ -835,14 +844,15 @@ pgf_parsing_complete(PgfParseState* before, PgfParseState* after,
 
 static void
 pgf_parsing_td_predict(PgfParseState* before, PgfParseState* after,
-                       PgfItem* item, PgfCCat* ccat, size_t lin_idx)
+                       PgfItem* item, PgfCCat* ccat, size_t lin_idx,
+                       float delta_prob)
 {
 	gu_enter("-> cat: %d", ccat->fid);
 	if (gu_seq_is_null(ccat->prods)) {
 		// Empty category
 		return;
 	}
-
+	
 	PgfItemBuf* conts = 
 		pgf_parsing_get_conts(before->conts_map, ccat, lin_idx, 
 		                      before->pool, before->pool);
@@ -856,17 +866,17 @@ pgf_parsing_td_predict(PgfParseState* before, PgfParseState* after,
 		PgfProductionSeq prods = ccat->prods;
 		for (size_t i = 0; i < ccat->n_synprods; i++) {
 			PgfProduction prod =
-				gu_seq_get(prods, PgfProduction, i);
-			pgf_parsing_production(before, ccat, lin_idx, prod, conts);
+				gu_seq_get(prods, PgfProduction, i);		
+			pgf_parsing_production(before, ccat, lin_idx, prod, conts, delta_prob);
 		}
-		
+
 		if (ccat->cnccat->abscat->meta_prob != INFINITY &&
 		    ccat->fid < before->ps->concr->total_cats) {
 			// Top-down prediction for meta rules
 			PgfItem *item =
-				pgf_new_item(before->offset, ccat, lin_idx, before->ps->meta_prod, conts, before->pool);
+				pgf_new_item(before->offset, ccat, lin_idx, before->ps->meta_prod, conts, 0, before->pool);
 			item->inside_prob = 
-				1000000 + ccat->cnccat->abscat->meta_prob * 1000;
+				ccat->cnccat->abscat->meta_prob;
 			gu_buf_heap_push(before->agenda, &pgf_item_prob_order, &item);
 		}
 
@@ -880,7 +890,7 @@ pgf_parsing_td_predict(PgfParseState* before, PgfParseState* after,
 				    new_item->base->lin_idx == lin_idx &&
 				    gu_seq_length(new_item->args) == 0) {
 					pgf_parsing_production(before, ccat, lin_idx,
-								           new_item->base->prod, conts);
+								           new_item->base->prod, conts, 0);
 				}
 			}
 		}
@@ -901,7 +911,7 @@ pgf_parsing_td_predict(PgfParseState* before, PgfParseState* after,
 					PgfProductionApply* papp = i.data;
 					if (gu_seq_length(papp->args) == 0) {
 						pgf_parsing_production(before, ccat, lin_idx,
-							prod, conts);
+							prod, conts, 0);
 					}
 					break;
 				}
@@ -931,67 +941,107 @@ pgf_parsing_td_predict(PgfParseState* before, PgfParseState* after,
 	gu_exit("<-");
 }
 
-static void
+static float
 pgf_parsing_bu_predict(PgfParseState* before, PgfParseState* after,
-                       PgfItem* item, PgfItem* meta_item, PgfItemBuf* agenda,
-                       bool print)
+                       PgfItemBuf* index, PgfItem* meta_item,
+                       PgfItemBuf* agenda)
 {
-	PgfItemBuf* conts =
-		pgf_parsing_get_conts(before->conts_map,
-							  item->base->ccat, item->base->lin_idx,
-							  before->pool, before->pool);
-	gu_buf_push(conts, PgfItem*, meta_item);	
-	if (gu_buf_length(conts) == 1) {
-		PgfItem* copy = pgf_item_copy(item, after->pool);
-		copy->base = pgf_item_base_copy(item->base, after->pool);
-		copy->base->conts = conts;
-		copy->outside_prob = 
-				meta_item->inside_prob+meta_item->outside_prob;
-		
-#ifdef PGF_PARSER_DEBUG
-		copy->start = before->offset;
-		copy->end   = before->offset;
+	float prob = INFINITY;
 
-		if (print) {
-			GuPool* tmp_pool = gu_new_pool();
-			GuOut* out = gu_file_out(stderr, tmp_pool);
-			GuWriter* wtr = gu_new_utf8_writer(out, tmp_pool);
-			GuExn* err = gu_exn(NULL, type, tmp_pool);
-			pgf_print_item(copy, wtr, err, tmp_pool);
-			gu_pool_free(tmp_pool);
-		} else {
-			copy->end = after->offset;
-		}
+	PgfMetaChildMap* meta_child_probs =
+		meta_item->base->ccat->cnccat->abscat->meta_child_probs;
+	if (meta_child_probs == NULL)
+		return prob;
+
+	if (!gu_map_has(before->generated_cats, index)) {
+		gu_map_put(before->generated_cats, index, PgfCCat*, NULL);
+
+		size_t n_items = gu_buf_length(index);
+		for (size_t i = 0; i < n_items; i++) {
+			PgfItem *item = gu_buf_get(index, PgfItem*, i);
+
+			float meta_prob =
+				meta_item->inside_prob+
+				meta_item->outside_prob+
+				gu_map_get(meta_child_probs, item->base->ccat->cnccat->abscat, float);
+
+			PgfItemBuf* conts =
+				pgf_parsing_get_conts(before->conts_map,
+									  item->base->ccat, item->base->lin_idx,
+									  before->pool, before->pool);
+			if (gu_buf_length(conts) == 0) {
+				float outside_prob =
+					pgf_parsing_bu_predict(before, after,
+										   item->base->conts, meta_item, 
+										   conts);
+
+				if (outside_prob > meta_prob)
+					outside_prob = meta_prob;
+
+				for (size_t j = i; j < n_items; j++) {
+					PgfItem *item_ = gu_buf_get(index, PgfItem*, j);
+
+					if (item->base->conts == item_->base->conts) {
+						PgfItem* copy = pgf_item_copy(item_, after->pool);
+						copy->base = pgf_item_base_copy(item_->base, after->pool);
+						copy->base->conts = conts;
+						copy->outside_prob = outside_prob;
+#ifdef PGF_PARSER_DEBUG
+						copy->start = before->offset;
+						copy->end   = (agenda == NULL)
+						                      ? after->offset
+							                  : before->offset;
 #endif
 
-		gu_buf_push(agenda, PgfItem*, copy);
+						if (agenda == NULL)
+							pgf_parsing_add_transition(before, after, after->ts->tok, copy);
+						else
+							gu_buf_push(agenda, PgfItem*, copy);
 
-		size_t n_items = gu_buf_length(item->base->conts);
-		for (size_t i = 0; i < n_items; i++) {
-			PgfItem *item_ = gu_buf_get(item->base->conts, PgfItem*, i);
-			pgf_parsing_bu_predict(before, after, item_, meta_item, conts, true);
-		}
-	} else {
-		/* If it has already been completed, combine. */
+						float item_prob = 
+							copy->inside_prob+copy->outside_prob;
+						if (prob > item_prob)
+							prob = item_prob;
+					}
+				}				
+			} else {
+				size_t n_items = gu_buf_length(conts);
+				for (size_t i = 0; i < n_items; i++) {
+					PgfItem *item = gu_buf_get(conts, PgfItem*, i);
+					
+					float item_prob = 
+						item->inside_prob+item->outside_prob;
+					if (prob > item_prob)
+						prob = item_prob;
+				}
+				prob += item->inside_prob;
 
-		/*PgfCCat* completed =
-			pgf_parsing_get_completed(before, conts);
-		if (completed) {
-			pgf_parsing_combine(before, after, meta_item, completed, item->base->lin_idx);
-		}*/
+				/* If it has already been completed, combine. */
 
-		PgfParseState* state = after;
-		while (state != NULL) {
-			PgfCCat* completed =
-				pgf_parsing_get_completed(state, conts);
-			if (completed) {
-				pgf_parsing_combine(state, state->next, meta_item, completed, item->base->lin_idx);
+				/*PgfCCat* completed =
+					pgf_parsing_get_completed(before, conts);
+				if (completed) {
+					pgf_parsing_combine(before, after, meta_item, completed, item->base->lin_idx);
+				}*/
+
+				PgfParseState* state = after;
+				while (state != NULL) {
+					PgfCCat* completed =
+						pgf_parsing_get_completed(state, conts);
+					if (completed) {
+						pgf_parsing_combine(state, state->next, meta_item, completed, item->base->lin_idx);
+					}
+
+					state = state->next;
+				}
 			}
-
-			state = state->next;
+			
+			if (meta_prob != INFINITY)
+				gu_buf_push(conts, PgfItem*, meta_item);
 		}
 	}
 
+	return prob;
 }
 
 static void
@@ -1002,7 +1052,7 @@ pgf_parsing_symbol(PgfParseState* before, PgfParseState* after,
 		PgfSymbolCat* scat = gu_variant_data(sym);
 		PgfPArg* parg = gu_seq_index(item->args, PgfPArg, scat->d);
 		gu_assert(!parg->hypos || !parg->hypos->len);
-		pgf_parsing_td_predict(before, after, item, parg->ccat, scat->r);
+		pgf_parsing_td_predict(before, after, item, parg->ccat, scat->r, 0);
 		break;
 	}
 	case PGF_SYMBOL_KS: {
@@ -1105,7 +1155,7 @@ pgf_parsing_symbol(PgfParseState* before, PgfParseState* after,
 
 			if (parg->ccat->fid > 0 &&
 			    parg->ccat->fid >= before->ps->concr->total_cats)
-				pgf_parsing_td_predict(before, after, item, parg->ccat, slit->r);
+				pgf_parsing_td_predict(before, after, item, parg->ccat, slit->r, 0);
 			else {
 				PgfItemBuf* conts = 
 					pgf_parsing_get_conts(before->conts_map, 
@@ -1133,7 +1183,7 @@ pgf_parsing_symbol(PgfParseState* before, PgfParseState* after,
 						pext->callback = callback;
 
 						pgf_parsing_production(before, parg->ccat, slit->r,
-											   prod, conts);
+											   prod, conts, 0);
 					}
 				} else {
 					/* If it has already been completed, combine. */
@@ -1168,6 +1218,7 @@ pgf_parsing_symbol(PgfParseState* before, PgfParseState* after,
 }
 
 PgfParseState *meta_after = NULL;
+static PgfLiteralCallback pgf_meta_callback;
 
 static void
 pgf_parsing_item(PgfParseState* before, PgfParseState* after, PgfItem* item)
@@ -1202,7 +1253,7 @@ pgf_parsing_item(PgfParseState* before, PgfParseState* after, PgfItem* item)
 		case 0:
 			pgf_parsing_td_predict(before, after, item, 
 					    pcoerce->coerce,
-					    item->base->lin_idx);
+					    item->base->lin_idx, 0);
 			break;
 		case 1:
 			pgf_parsing_complete(before, after, item, NULL);
@@ -1241,6 +1292,14 @@ pgf_parsing_item(PgfParseState* before, PgfParseState* after, PgfItem* item)
 				pgf_parsing_complete(before, after, item, before->meta_ep);
 
 			if (accepted && after != NULL) {
+				if (pext->callback == &pgf_meta_callback) {
+					float meta_token_prob = 
+						item->base->ccat->cnccat->abscat->meta_token_prob;
+					if (meta_token_prob == INFINITY)
+						break;
+					item->inside_prob += meta_token_prob;
+				}
+
 				PgfSymbol prev = item->curr_sym;
 				PgfSymbolKS* sks = (PgfSymbolKS*)
 					gu_alloc_variant(PGF_SYMBOL_KS,
@@ -1265,6 +1324,48 @@ pgf_parsing_item(PgfParseState* before, PgfParseState* after, PgfItem* item)
 	}
 }
 
+typedef struct {
+	GuMapItor fn;
+	PgfParseState* before;
+	PgfParseState* after;
+	PgfItem* meta_item;
+} PgfMetaPredictFn;
+
+static void
+pgf_parsing_meta_predict(GuMapItor* fn, const void* key, void* value, GuExn* err)
+{
+	(void) (err);
+	
+	PgfCId abscat = *((PgfCId*) key);
+    float meta_prob = *((float*) value);
+    PgfMetaPredictFn* clo = (PgfMetaPredictFn*) fn;
+    PgfParseState* before = clo->before;
+    PgfParseState* after  = clo->after;
+    PgfItem* meta_item  = clo->meta_item;
+{    
+    GuPool* tmp_pool = gu_new_pool();
+    GuOut* out = gu_file_out(stdout, tmp_pool);
+    GuWriter* wtr = gu_new_utf8_writer(out, tmp_pool);
+    GuExn* err = gu_exn(NULL, type, tmp_pool);
+    gu_string_write(abscat, wtr, err);
+	gu_pool_free(tmp_pool);
+}
+    PgfCncCat* cnccat =
+		gu_map_get(before->ps->concr->cnccats, &abscat, PgfCncCat*);
+	if (cnccat == NULL)
+		return;
+
+	size_t n_cats = gu_list_length(cnccat->cats);
+	for (size_t i = 0; i < n_cats; i++) {
+		PgfCCat* ccat = gu_list_index(cnccat->cats, i);
+		
+		for (size_t lin_idx = 0; lin_idx < cnccat->n_lins; lin_idx++) {
+			pgf_parsing_td_predict(before, after,
+									meta_item, ccat, lin_idx, meta_prob);
+		}
+	}
+}
+
 static bool
 pgf_match_meta(PgfConcr* concr, PgfItem *item, PgfToken tok,
                PgfExprProb** out_ep, GuPool *pool)
@@ -1298,14 +1399,18 @@ pgf_match_meta(PgfConcr* concr, PgfItem *item, PgfToken tok,
 			PgfParseState* before = 
 				gu_container(out_ep, PgfParseState, meta_ep);
 
-			size_t n_items = gu_buf_length(after->ts->lexicon_idx);
-			for (size_t i = 0; i < n_items; i++) {
-				PgfItem* item_ = 
-					gu_buf_get(after->ts->lexicon_idx, PgfItem*, i);
-				pgf_parsing_bu_predict(before, after,
-									   item_, item, after->agenda, false);
-				after->ps->target = item_;
+			PgfCIdMap* meta_child_probs =
+				item->base->ccat->cnccat->abscat->meta_child_probs;
+			if (meta_child_probs != NULL) {
+				PgfMetaPredictFn clo = { { pgf_parsing_meta_predict }, before, after, item };
+				gu_map_iter(meta_child_probs, &clo.fn, NULL);
 			}
+/*
+			fprintf(stderr, "------------------------------------\n");
+			pgf_parsing_bu_predict(before, after,
+								   after->ts->lexicon_idx, item, 
+								   NULL);
+			fprintf(stderr, "------------------------------------\n");*/
 			return false;
 		}
 	}
@@ -1651,14 +1756,14 @@ pgf_parser_init_state(PgfConcr* concr, PgfCId cat, size_t lin_idx, GuPool* pool)
                 PgfProduction prod =
                     gu_seq_get(prods, PgfProduction, i);
                 PgfItem* item = 
-                    pgf_new_item(0, ccat, lin_idx, prod, conts, pool);
+                    pgf_new_item(0, ccat, lin_idx, prod, conts, 0, pool);
                 gu_buf_heap_push(state->agenda, &pgf_item_prob_order, &item);
             }
             
          	PgfItem *item =
-				pgf_new_item(0, ccat, lin_idx, ps->meta_prod, conts, pool);
+				pgf_new_item(0, ccat, lin_idx, ps->meta_prod, conts, 0, pool);
 			item->inside_prob = 
-				1000000 + ccat->cnccat->abscat->meta_prob * 1000;
+				ccat->cnccat->abscat->meta_prob;
 			gu_buf_heap_push(state->agenda, &pgf_item_prob_order, &item);
 		}
 	}
@@ -1896,7 +2001,7 @@ pgf_parser_bu_index(PgfConcr* concr, PgfCCat* ccat, PgfProduction prod,
 			pgf_parsing_get_conts(conts_map, ccat, lin_idx,
 			                      pool, tmp_pool);
 		PgfItem* item =
-			pgf_new_item(0, ccat, lin_idx, prod, conts, pool);
+			pgf_new_item(0, ccat, lin_idx, prod, conts, 0, pool);
 
 		pgf_parser_bu_item(concr, item, conts_map, pool, tmp_pool);
 	}

src/runtime/c/pgf/pgf.h

@@ -69,6 +69,9 @@ pgf_read(GuIn* in, GuPool* pool, GuExn* err);
  */
 
 
+bool
+pgf_load_meta_child_probs(PgfPGF*, const char* fpath, GuPool* pool);
+
 #include <gu/type.h>
 extern GU_DECLARE_TYPE(PgfPGF, struct);
 

src/runtime/c/pgf/reader.c

@@ -30,6 +30,7 @@
 #include <gu/exn.h>
 #include <gu/utf8.h>
 #include <math.h>
+#include <stdio.h>
 
 #define GU_LOG_ENABLE
 #include <gu/log.h>
@@ -656,6 +657,8 @@ pgf_compute_meta_probs(GuMapItor* fn, const void* key, void* value, GuExn* err)
 		mass += cat->functions[i].prob;
 	}
     cat->meta_prob = - log(fabs(1 - mass));
+	cat->meta_token_prob = INFINITY;
+    cat->meta_child_probs = NULL;
 }
 
 static void
@@ -936,3 +939,51 @@ pgf_read(GuIn* in, GuPool* pool, GuExn* err)
 	gu_return_on_exn(err, NULL);
 	return pgf;
 }
+
+bool
+pgf_load_meta_child_probs(PgfPGF* pgf, const char* fpath, GuPool* pool)
+{
+	FILE *fp = fopen(fpath, "r");
+	if (!fp)
+		return false;
+
+	GuPool* tmp_pool = gu_new_pool();
+	
+	for (;;) {
+		char cat1_s[21];
+		char cat2_s[21];
+		float prob;
+
+		if (fscanf(fp, "%20s\t%20s\t%f", cat1_s, cat2_s, &prob) < 3)
+			break;
+
+		prob = - log(prob);
+
+		GuString cat1 = gu_str_string(cat1_s, tmp_pool);
+		PgfCat* abscat1 =
+			gu_map_get(pgf->abstract.cats, &cat1, PgfCat*);
+		if (abscat1 == NULL)
+			return false;
+
+		if (strcmp(cat2_s, "_") == 0) {
+			abscat1->meta_token_prob = prob;
+		} else {
+			GuString cat2 = gu_str_string(cat2_s, tmp_pool);			
+			PgfCat* abscat2 = gu_map_get(pgf->abstract.cats, &cat2, PgfCat*);
+			if (abscat2 == NULL)
+				return false;
+
+			if (abscat1->meta_child_probs == NULL) {
+				abscat1->meta_child_probs = 
+					gu_map_type_new(PgfMetaChildMap, pool);
+			}
+
+			gu_map_put(abscat1->meta_child_probs, abscat2, float, prob);
+		}
+	}
+	
+	gu_pool_free(tmp_pool);
+
+	fclose(fp);
+	return true;
+}

src/runtime/c/utils/pgf-translate.c

@@ -87,6 +87,12 @@ int main(int argc, char* argv[]) {
 		goto fail_read;
 	}
 
+	if (!pgf_load_meta_child_probs(pgf, "../../../examples/PennTreebank/test2.probs", pool)) {
+		fprintf(stderr, "Loading meta child probs failed\n");
+		status = EXIT_FAILURE;
+		goto fail_read;
+	}
+
 	// Look up the source and destination concrete categories
 	PgfConcr* from_concr =
 		gu_map_get(pgf->concretes, &from_lang, PgfConcr*);