1 files changed, 251 insertions, 158 deletions

diff --git a/src/runtime/c/pgf/lookup.c b/src/runtime/c/pgf/lookup.c
index 53a70f36c..8fa94e19c 100644
--- a/src/runtime/c/pgf/lookup.c
+++ b/src/runtime/c/pgf/lookup.c
@@ -6,6 +6,8 @@
 #include <gu/choice.h>
 #include <pgf/data.h>
 #include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
 
 //#define PGF_LOOKUP_DEBUG
 
@@ -98,7 +100,7 @@ pgf_lookup_index_syms(GuMap* lexicon_idx, PgfSymbols* syms, PgfProductionIdx* id
 
 typedef struct {
 	GuMap* function_idx;
-	GuMap* cat_ids;
+	GuMap* meta_ids;
 	GuBuf* spine;
 	GuPool* pool;
 } PgfSpineBuilder;
@@ -124,15 +126,15 @@ pgf_lookup_add_production(PgfSpineBuilder* builder, PgfMetaId id, PgfAbsProducti
 
 static PgfMetaId
 pgf_lookup_add_spine_nodes(PgfSpineBuilder* builder, PgfCId cat) {
-	PgfMetaId cat_id = gu_map_get(builder->cat_ids, cat, PgfMetaId);
-	if (cat_id != 0) {
-		return cat_id;
+	PgfMetaId meta_id = gu_map_get(builder->meta_ids, cat, PgfMetaId);
+	if (meta_id != 0) {
+		return meta_id;
 	}
 
-	cat_id = gu_buf_length(builder->spine);
+	meta_id = gu_buf_length(builder->spine);
 	gu_buf_push(builder->spine, GuBuf*, gu_new_buf(PgfAbsProduction*, builder->pool));
 
-	gu_map_put(builder->cat_ids, cat, PgfMetaId, cat_id);
+	gu_map_put(builder->meta_ids, cat, PgfMetaId, meta_id);
 
 	GuBuf* entries = gu_map_get(builder->function_idx, cat, GuBuf*);
 	if (entries != NULL) {
@@ -143,13 +145,13 @@ pgf_lookup_add_spine_nodes(PgfSpineBuilder* builder, PgfCId cat) {
 			PgfMetaId id = pgf_lookup_add_spine_nodes(builder, entry->fun->type->cid);
 			
 			PgfAbsProduction* prod = pgf_lookup_new_production(entry->fun, builder->pool);
-			prod->args[entry->arg_idx] = cat_id;
+			prod->args[entry->arg_idx] = meta_id;
 			
 			pgf_lookup_add_production(builder, id, prod);
 		}
 	}
 
-	return cat_id;
+	return meta_id;
 }
 
 static void
@@ -164,12 +166,12 @@ pgf_lookup_add_spine_leaf(PgfSpineBuilder* builder, PgfAbsFun *fun)
 
 static GuBuf*
 pgf_lookup_build_spine(GuMap* lexicon_idx, GuMap* function_idx,
-                       GuString tok, PgfType* typ, PgfMetaId* cat_id,
+                       GuString tok, PgfType* typ, PgfMetaId* meta_id,
                        GuPool* pool)
 {
 	PgfSpineBuilder builder;
 	builder.function_idx = function_idx;
-	builder.cat_ids      = gu_new_string_map(PgfMetaId, &gu_null_struct, pool);
+	builder.meta_ids     = gu_new_string_map(PgfMetaId, &gu_null_struct, pool);
 	builder.spine        = gu_new_buf(GuBuf*, pool);
 	builder.pool         = pool;
 	
@@ -185,7 +187,7 @@ pgf_lookup_build_spine(GuMap* lexicon_idx, GuMap* function_idx,
 		}
 	}
 
-	*cat_id = gu_map_get(builder.cat_ids, typ->cid, PgfMetaId);
+	*meta_id = gu_map_get(builder.meta_ids, typ->cid, PgfMetaId);
 
 	return builder.spine;
 }
@@ -219,32 +221,32 @@ pgf_pair_hasher[1] = {
 
 static PgfMetaId
 pgf_lookup_merge_cats(GuBuf* spine, GuMap* pairs,
-                      PgfMetaId cat_id1, GuBuf* spine1,
-                      PgfMetaId cat_id2, GuBuf* spine2,
+                      PgfMetaId meta_id1, GuBuf* spine1,
+                      PgfMetaId meta_id2, GuBuf* spine2,
                       GuPool* pool)
 {
-	if (cat_id1 == 0 && cat_id2 == 0)
+	if (meta_id1 == 0 && meta_id2 == 0)
 		return 0;
 
 	PgfPair pair;
-	pair[0] = cat_id1;
-	pair[1] = cat_id2;
-	PgfMetaId cat_id = gu_map_get(pairs, &pair, PgfMetaId);
-	if (cat_id != 0)
-		return cat_id;
+	pair[0] = meta_id1;
+	pair[1] = meta_id2;
+	PgfMetaId meta_id = gu_map_get(pairs, &pair, PgfMetaId);
+	if (meta_id != 0)
+		return meta_id;
 
-	cat_id = gu_buf_length(spine);
+	meta_id = gu_buf_length(spine);
 	GuBuf* id_prods = gu_new_buf(PgfAbsProduction*, pool);
 	gu_buf_push(spine, GuBuf*, id_prods);
 
-	gu_map_put(pairs, &pair, PgfMetaId, cat_id);
+	gu_map_put(pairs, &pair, PgfMetaId, meta_id);
 
-	GuBuf* id_prods1 = gu_buf_get(spine1, GuBuf*, cat_id1);
-	GuBuf* id_prods2 = gu_buf_get(spine2, GuBuf*, cat_id2);
-	size_t n_id_prods1 = (cat_id1 == 0) ? 0 : gu_buf_length(id_prods1);
-	size_t n_id_prods2 = (cat_id2 == 0) ? 0 : gu_buf_length(id_prods2);
+	GuBuf* id_prods1 = gu_buf_get(spine1, GuBuf*, meta_id1);
+	GuBuf* id_prods2 = gu_buf_get(spine2, GuBuf*, meta_id2);
+	size_t n_id_prods1 = (meta_id1 == 0) ? 0 : gu_buf_length(id_prods1);
+	size_t n_id_prods2 = (meta_id2 == 0) ? 0 : gu_buf_length(id_prods2);
 
-	if (cat_id1 != 0) {
+	if (meta_id1 != 0) {
 		for (size_t i = 0; i < n_id_prods1; i++) {
 			PgfAbsProduction* prod1 =
 				gu_buf_get(id_prods1, PgfAbsProduction*, i);
@@ -287,7 +289,7 @@ pgf_lookup_merge_cats(GuBuf* spine, GuMap* pairs,
 		}
 	}
 
-	if (cat_id2 != 0) {
+	if (meta_id2 != 0) {
 		for (size_t i = 0; i < n_id_prods2; i++) {
 			PgfAbsProduction* prod2 =
 				gu_buf_get(id_prods2, PgfAbsProduction*, i);
@@ -318,13 +320,13 @@ pgf_lookup_merge_cats(GuBuf* spine, GuMap* pairs,
 		}
 	}
 
-	return cat_id;
+	return meta_id;
 }
 
 static GuBuf*
-pgf_lookup_merge(PgfMetaId cat_id1, GuBuf* spine1,
-                 PgfMetaId cat_id2, GuBuf* spine2,
-                 PgfMetaId* cat_id,
+pgf_lookup_merge(PgfMetaId meta_id1, GuBuf* spine1,
+                 PgfMetaId meta_id2, GuBuf* spine2,
+                 PgfMetaId* meta_id,
                  GuPool* pool, GuPool* out_pool)
 {
 	GuBuf* spine = gu_new_buf(GuBuf*, out_pool);
@@ -332,105 +334,69 @@ pgf_lookup_merge(PgfMetaId cat_id1, GuBuf* spine1,
 
 	GuMap* pairs = gu_new_map(PgfPair, pgf_pair_hasher, PgfMetaId, &gu_null_struct, pool);
 
-	*cat_id =
+	*meta_id =
 		pgf_lookup_merge_cats(spine, pairs,
-		                      cat_id1, spine1,
-		                      cat_id2, spine2,
+		                      meta_id1, spine1,
+		                      meta_id2, spine2,
 		                      out_pool);
 
 	return spine;
 }
 
-static bool
-pgf_lookup_filter(GuBuf* join, PgfMetaId cat_id, GuSeq* counts, GuBuf* stack)
-{
-	if (cat_id == 0)
-		return true;
-
-	size_t count = gu_seq_get(counts, size_t, cat_id);
-	if (count > 0)
-		return true;
-
-	size_t n_stack = gu_buf_length(stack);
-	for (size_t i = 0; i < n_stack; i++) {
-		PgfMetaId id = gu_buf_get(stack, PgfMetaId, i);
-		if (cat_id == id) {
-			return false;
-		}
-	}
-	gu_buf_push(stack, PgfMetaId, cat_id);
-
-	size_t pos = 0;
-	size_t maximum = 0;
-	GuBuf* id_prods = gu_buf_get(join, GuBuf*, cat_id);
-	size_t n_id_prods = gu_buf_length(id_prods);
-	for (size_t i = 0; i < n_id_prods; i++) {
-		PgfAbsProduction* prod = 
-			gu_buf_get(id_prods, PgfAbsProduction*, i);
-
-		size_t n_args = gu_seq_length(prod->fun->type->hypos);
-		size_t sum = prod->count;
-		for (size_t j = 0; j < n_args; j++) {
-			if (!pgf_lookup_filter(join, prod->args[j], counts, stack)) {
-				sum = 0;
-				break;
-			}
-			sum += gu_seq_get(counts, size_t, prod->args[j]);
-		}
-
-		if (sum > maximum) {
-			maximum = sum;
-			pos = 0;
-		}
-		if (sum == maximum) {
-			gu_buf_set(id_prods, PgfAbsProduction*, pos, prod);
-			pos++;
-		}
-
-		prod->count = sum;
-	}
-
-	gu_seq_set(counts, size_t, cat_id, maximum);
-	gu_buf_trim_n(id_prods, n_id_prods-pos);
-
-	gu_buf_pop(stack, PgfMetaId);
-
-	return true;
-}
-
 typedef struct {
-	GuEnum en;
 	GuBuf* join;
 	PgfMetaId start_id;
 	GuChoice* choice;
+	GuBuf* stack;
+	GuBuf* exprs;
 	GuPool* out_pool;
+} PgfLookupState;
+
+typedef struct {
+	GuEnum en;
+	double max;
+	size_t index;
+	GuBuf* exprs;
 } PgfLookupEnum;
 
-static void
-pgf_lookup_extract(PgfLookupEnum* st, PgfMetaId cat_id, PgfExprProb* ep)
+static bool
+pgf_lookup_extract(PgfLookupState* st, PgfMetaId meta_id, PgfExprProb* ep)
 {
-	GuBuf* id_prods = gu_buf_get(st->join, GuBuf*, cat_id);
-	
+	GuBuf* id_prods = gu_buf_get(st->join, GuBuf*, meta_id);
+
 	if (id_prods == NULL || gu_buf_length(id_prods) == 0) {
 		ep->expr = gu_new_variant_i(st->out_pool,
 					                PGF_EXPR_META,
 					                PgfExprMeta,
-					                cat_id);
+					                meta_id);
 		ep->prob = 0;
-		return;
+		return true;
 	}
 
+	size_t n_stack = gu_buf_length(st->stack);
+	for (size_t i = 0; i < n_stack; i++) {
+		PgfMetaId id = gu_buf_get(st->stack, PgfMetaId, i);
+		if (meta_id == id) {
+			return false;
+		}
+	}
+	gu_buf_push(st->stack, PgfMetaId, meta_id);
+
 	size_t n_id_prods = gu_buf_length(id_prods);
 
 	size_t i = gu_choice_next(st->choice, n_id_prods);
-	PgfAbsProduction* prod = 
+	PgfAbsProduction* prod =
 		gu_buf_get(id_prods, PgfAbsProduction*, i);
 
 	*ep = prod->fun->ep;
+	bool res = true;
 	size_t n_args = gu_seq_length(prod->fun->type->hypos);
 	for (size_t j = 0; j < n_args; j++) {
 		PgfExprProb ep_arg;
-		pgf_lookup_extract(st, prod->args[j], &ep_arg);
+		if (!pgf_lookup_extract(st, prod->args[j], &ep_arg)) {
+			res = false;
+			break;
+		}
 
 		ep->expr = gu_new_variant_i(st->out_pool,
 						PGF_EXPR_APP,
@@ -438,29 +404,124 @@ pgf_lookup_extract(PgfLookupEnum* st, PgfMetaId cat_id, PgfExprProb* ep)
 						ep->expr, ep_arg.expr);
 		ep->prob += ep_arg.prob;
 	}
+	
+	gu_buf_pop(st->stack, PgfMetaId);
+	return res;
 }
 
-static void
-pgf_lookup_enum_next(GuEnum* self, void* to, GuPool* pool)
+static GuBuf*
+pgf_lookup_tokenize(GuString buf, size_t len, GuPool* pool)
+{	
+	GuBuf* tokens = gu_new_buf(GuString, pool);
+
+	GuUCS c = ' ';
+	const uint8_t* p = (const uint8_t*) buf;
+	for (;;) {
+		while (gu_ucs_is_space(c)) {
+			c = gu_utf8_decode(&p);
+		}
+		if (c == 0)
+			break;
+
+		const uint8_t* start = p-1;
+		while (c != 0 && !gu_ucs_is_space(c)) {
+			c = gu_utf8_decode(&p);
+		}
+		const uint8_t* end   = p-1;
+
+		size_t len = end-start;
+		GuString tok = gu_malloc(pool, len+1);
+		memcpy((uint8_t*) tok, start, len);
+		((uint8_t*) tok)[len] = 0;
+
+		gu_buf_push(tokens, GuString, tok);
+	}
+	
+	return tokens;
+}
+
+static int
+pgf_lookup_compute_kernel_helper1(GuBuf* sentence_tokens, GuBuf* expr_tokens,
+                                  int* matrix, size_t i, size_t j);
+
+static int
+pgf_lookup_compute_kernel_helper2(GuBuf* sentence_tokens, GuBuf* expr_tokens,
+                                  int* matrix, size_t i, size_t j)
 {
-	PgfLookupEnum* st = gu_container(self, PgfLookupEnum, en);
+//	size_t n_sentence_tokens = gu_buf_length(sentence_tokens);
+	size_t n_expr_tokens     = gu_buf_length(expr_tokens);
 	
-	if (st->choice == NULL) {
-		*((PgfExprProb**) to) = NULL;
-		return;
+	if (j >= n_expr_tokens)
+		return 0;
+		
+	GuString sentence_token = gu_buf_get(sentence_tokens, GuString, i);
+	GuString expr_token     = gu_buf_get(expr_tokens, GuString, j);
+	if (strcmp(sentence_token, expr_token) == 0) {
+		return 1 + 
+		       pgf_lookup_compute_kernel_helper1(sentence_tokens, expr_tokens,
+                                                 matrix, i+1, j+1) +
+               pgf_lookup_compute_kernel_helper2(sentence_tokens, expr_tokens,
+                                                 matrix, i,   j+1);
+	} else {
+		return pgf_lookup_compute_kernel_helper2(sentence_tokens, expr_tokens, matrix, i, j+1);
 	}
+}
 
-	GuChoiceMark mark = gu_choice_mark(st->choice);
+static int
+pgf_lookup_compute_kernel_helper1(GuBuf* sentence_tokens, GuBuf* expr_tokens,
+                                  int* matrix, size_t i, size_t j)
+{
+	size_t n_sentence_tokens = gu_buf_length(sentence_tokens);
+//	size_t n_expr_tokens     = gu_buf_length(expr_tokens);
+
+	int score = matrix[i+n_sentence_tokens*j];
+	if (score == -1) {
+		if (i >= n_sentence_tokens)
+			score = 0;
+		else
+			score = pgf_lookup_compute_kernel_helper1(sentence_tokens, expr_tokens,
+                                                      matrix, i+1, j)
+                  + pgf_lookup_compute_kernel_helper2(sentence_tokens, expr_tokens,
+                                                      matrix, i,   j);
+		matrix[n_sentence_tokens*i + j] = score;
+	}
 
-	PgfExprProb* ep = gu_new(PgfExprProb, pool);
-	pgf_lookup_extract(st, st->start_id, ep);
-	*((PgfExprProb**) to) = ep;
+	return score;
+}
+
+static int
+pgf_lookup_compute_kernel(GuBuf* sentence_tokens, GuBuf* expr_tokens)
+{
+	size_t n_sentence_tokens = gu_buf_length(sentence_tokens);
+	size_t n_expr_tokens     = gu_buf_length(expr_tokens);
+	size_t size              = (n_sentence_tokens+1)*(n_expr_tokens+1)*sizeof(int);
+	int* matrix = alloca(size);
+	memset(matrix, -1, size);
+
+	return pgf_lookup_compute_kernel_helper1(sentence_tokens, expr_tokens, matrix, 0, 0);
+}
 
-	gu_choice_reset(st->choice, mark);
+typedef struct {
+	PgfExprProb ep;
+	double score;
+} PgfExprScore;
 
-	if (!gu_choice_advance(st->choice)) {
-		st->choice = NULL;
+static void
+pgf_lookup_enum_next(GuEnum* self, void* to, GuPool* pool)
+{
+	PgfLookupEnum* st = gu_container(self, PgfLookupEnum, en);
+	PgfExprScore* es = NULL;
+
+	while (st->index < gu_buf_length(st->exprs)) {
+		es = gu_buf_index(st->exprs, PgfExprScore, st->index);
+		st->index++;
+		if (fabs(es->score - st->max) < 0.00005) {
+			*((PgfExprProb**) to) = &es->ep;
+			return;
+		}
 	}
+
+	*((PgfExprProb**) to) = NULL;
 }
 
 PGF_API GuEnum*
@@ -500,52 +561,26 @@ pgf_lookup_sentence(PgfConcr* concr, PgfType* typ, GuString sentence, GuPool* po
 
 	GuPool *work_pool = gu_new_pool();
 
-	PgfMetaId cat_id1 = 0;
+	GuBuf* sentence_tokens =
+		pgf_lookup_tokenize(sentence,
+		                    strlen(sentence),
+		                    work_pool);
+
+	PgfMetaId meta_id1 = 0;
 	GuBuf* join = gu_new_buf(GuBuf*, pool);
 	gu_buf_push(join, GuBuf*, NULL);
 
-	GuUCS c = ' ';
-	const uint8_t* p = (const uint8_t*) sentence;
-	for (;;) {
-		while (gu_ucs_is_space(c)) {
-			c = gu_utf8_decode(&p);
-		}
-		if (c == 0)
-			break;
+	size_t n_tokens = gu_buf_length(sentence_tokens);
+	for (size_t i = 0; i < n_tokens; i++) {
+		GuString tok = gu_buf_get(sentence_tokens, GuString, i);
 
-		const uint8_t* start = p-1;
-		while (c != 0 && !gu_ucs_is_space(c)) {
-			c = gu_utf8_decode(&p);
-		}
-		const uint8_t* end   = p-1;
-
-		size_t len = end-start;
-		GuString tok = gu_malloc(work_pool, len+1);
-		memcpy((uint8_t*) tok, start, len);
-		((uint8_t*) tok)[len] = 0;
-
-		PgfMetaId cat_id2 = 0;
+		PgfMetaId meta_id2 = 0;
 		GuBuf* spine =
 			pgf_lookup_build_spine(lexicon_idx, function_idx,
-			                       tok, typ, &cat_id2,
+			                       tok, typ, &meta_id2,
 			                       work_pool);
 
-		join = pgf_lookup_merge(cat_id1, join, cat_id2, spine, &cat_id1, work_pool, pool);
-	}
-
-
-	size_t n_cats = gu_buf_length(join);
-	GuBuf* stack = gu_new_buf(PgfMetaId, work_pool);
-	GuSeq* counts = gu_new_seq(size_t, n_cats, work_pool);
-	for (size_t i = 0; i < n_cats; i++) {
-		gu_seq_set(counts, size_t, i, 0);
-	}
-	pgf_lookup_filter(join, cat_id1, counts, stack);
-	for (size_t i = 1; i < n_cats; i++) {
-		if (gu_seq_get(counts, size_t, i) == 0) {
-			GuBuf* id_prods = gu_buf_get(join, GuBuf*, i);
-			gu_buf_flush(id_prods);
-		}
+		join = pgf_lookup_merge(meta_id1, join, meta_id2, spine, &meta_id1, work_pool, pool);
 	}
 
 #ifdef PGF_LOOKUP_DEBUG
@@ -557,13 +592,71 @@ pgf_lookup_sentence(PgfConcr* concr, PgfType* typ, GuString sentence, GuPool* po
 	gu_pool_free(tmp_pool);
 #endif
 
+	PgfLookupState st;
+	st.join    = join;
+	st.start_id= meta_id1;
+	st.choice  = gu_new_choice(work_pool);
+	st.stack   = gu_new_buf(PgfMetaId, work_pool);
+	st.exprs   = gu_new_buf(PgfExprScore, pool);
+	st.out_pool= out_pool;
+
+	GuChoiceMark mark = gu_choice_mark(st.choice);
+
+	double max = 0;
+	PgfExprScore* es = gu_buf_extend(st.exprs);
+	for (;;) {
+		bool res = pgf_lookup_extract(&st, st.start_id, &es->ep);
+
+		gu_choice_reset(st.choice, mark);
+
+		if (!gu_choice_advance(st.choice))
+			break;
+
+		if (res) {
+			GuExn* err = gu_exn(work_pool);
+			GuStringBuf* sbuf = gu_new_string_buf(work_pool);
+			GuOut* out = gu_string_buf_out(sbuf);
+
+			pgf_linearize(concr, es->ep.expr, out, err);
+			if (!gu_ok(err)) {
+				continue;
+			}
+
+			GuBuf* expr_tokens =
+				pgf_lookup_tokenize(gu_string_buf_data(sbuf),
+									gu_string_buf_length(sbuf),
+									work_pool);
+
+			es->score =
+				((double) pgf_lookup_compute_kernel(sentence_tokens, expr_tokens)) /
+				sqrt(((double) pgf_lookup_compute_kernel(sentence_tokens, sentence_tokens)) * ((double) pgf_lookup_compute_kernel(expr_tokens, expr_tokens)));
+
+#ifdef PGF_LOOKUP_DEBUG
+			{
+				GuPool* tmp_pool = gu_new_pool();
+				GuOut* out = gu_file_out(stderr, tmp_pool);
+				GuExn* err = gu_exn(tmp_pool);
+				pgf_print_expr(es->ep.expr, NULL, 0, out, err);
+				gu_printf(out, err, " [%f]\n", es->score);
+				gu_pool_free(tmp_pool);
+			}
+#endif
+
+			if (es->score > max) {
+				max = es->score;
+			}
+
+			es = gu_buf_extend(st.exprs);
+		}
+	}
+	gu_buf_trim(st.exprs);
+
 	gu_pool_free(work_pool);
 
-	PgfLookupEnum* st = gu_new(PgfLookupEnum, pool);
-	st->en.next = pgf_lookup_enum_next;
-	st->join    = join;
-	st->start_id= cat_id1;
-	st->choice  = gu_new_choice(pool);
-	st->out_pool= out_pool;
-	return &st->en;
+	PgfLookupEnum* lenum = gu_new(PgfLookupEnum, pool);
+	lenum->en.next = pgf_lookup_enum_next;
+	lenum->max     = max;
+	lenum->index   = 0;
+	lenum->exprs   = st.exprs;
+	return &lenum->en;
 }