Add blank node type for value, to allow the user to 'join' statement

queries on blank node values with the simple get_value functions.

Remove use of SPARQL from lv2_inspect.


git-svn-id: http://svn.drobilla.net/lad/trunk/slv2@2874 a436a847-0d15-0410-975c-d299462d15a1

3 files changed, 35 insertions, 4 deletions

diff --git a/src/plugin.c b/src/plugin.c
index 45177e1..a7e211e 100644
--- a/src/plugin.c
+++ b/src/plugin.c
@@ -522,8 +522,8 @@ slv2_plugin_get_value_for_subject(SLV2Plugin p,
                                   SLV2Value  subject,
                                   SLV2Value  predicate)
 {
-	if ( ! slv2_value_is_uri(subject)) {
-		SLV2_ERROR("Subject is not a URI\n");
+	if ( ! slv2_value_is_uri(subject) && ! slv2_value_is_blank(subject)) {
+		SLV2_ERROR("Subject is not a resource\n");
 		return NULL;
 	}
 	if ( ! slv2_value_is_uri(predicate)) {
@@ -531,9 +531,15 @@ slv2_plugin_get_value_for_subject(SLV2Plugin p,
 		return NULL;
 	}
 
+	librdf_node* subject_node = (slv2_value_is_uri(subject))
+		? librdf_new_node_from_uri(
+			p->world->world, subject->val.uri_val)
+		: librdf_new_node_from_blank_identifier(
+			p->world->world, (const uint8_t*)slv2_value_as_blank(subject));
+
 	return slv2_plugin_query_node(
 		p,
-		librdf_new_node_from_uri(p->world->world, subject->val.uri_val),
+		subject_node,
 		librdf_new_node_from_uri(p->world->world, predicate->val.uri_val));
 }
 
diff --git a/src/slv2_internal.h b/src/slv2_internal.h
index 08d223f..af748bb 100644
--- a/src/slv2_internal.h
+++ b/src/slv2_internal.h
@@ -242,6 +242,7 @@ typedef enum _SLV2ValueType {
 	SLV2_VALUE_STRING,
 	SLV2_VALUE_INT,
 	SLV2_VALUE_FLOAT,
+	SLV2_VALUE_BLANK
 } SLV2ValueType;
 
 struct _SLV2Value {
diff --git a/src/value.c b/src/value.c
index d9e8a9c..819e5fe 100644
--- a/src/value.c
+++ b/src/value.c
@@ -37,6 +37,7 @@ slv2_value_set_numerics_from_string(SLV2Value val)
 
 	switch (val->type) {
 	case SLV2_VALUE_URI:
+	case SLV2_VALUE_BLANK:
 	case SLV2_VALUE_QNAME_UNUSED:
 	case SLV2_VALUE_STRING:
 		break;
@@ -79,6 +80,7 @@ slv2_value_new(SLV2World world, SLV2ValueType type, const char* str)
 		val->str_val = (char*)librdf_uri_as_string(val->val.uri_val);
 		break;
 	case SLV2_VALUE_QNAME_UNUSED:
+	case SLV2_VALUE_BLANK:
 	case SLV2_VALUE_STRING:
 	case SLV2_VALUE_INT:
 	case SLV2_VALUE_FLOAT:
@@ -117,6 +119,7 @@ slv2_value_new_librdf_node(SLV2World world, librdf_node* node)
 		result = slv2_value_new(world, type, (const char*)librdf_node_get_literal_value(node));
 		switch (result->type) {
 		case SLV2_VALUE_URI:
+		case SLV2_VALUE_BLANK:
 		case SLV2_VALUE_STRING:
 		case SLV2_VALUE_QNAME_UNUSED:
 			break;
@@ -126,7 +129,7 @@ slv2_value_new_librdf_node(SLV2World world, librdf_node* node)
 		}
 		break;
 	case LIBRDF_NODE_TYPE_BLANK:
-		type = SLV2_VALUE_STRING;
+		type = SLV2_VALUE_BLANK;
 		result = slv2_value_new(world, type, (const char*)librdf_node_get_blank_identifier(node));
 		break;
 	case LIBRDF_NODE_TYPE_UNKNOWN:
@@ -236,6 +239,7 @@ slv2_value_equals(SLV2Value value, SLV2Value other)
 	switch (value->type) {
 	case SLV2_VALUE_URI:
 		return (librdf_uri_equals(value->val.uri_val, other->val.uri_val) != 0);
+	case SLV2_VALUE_BLANK:
 	case SLV2_VALUE_STRING:
 	case SLV2_VALUE_QNAME_UNUSED:
 		return ! strcmp(value->str_val, other->str_val);
@@ -262,6 +266,11 @@ slv2_value_get_turtle_token(SLV2Value value)
 		result = calloc(len, 1);
 		snprintf(result, len, "<%s>", value->str_val);
 		break;
+	case SLV2_VALUE_BLANK:
+		len = strlen(value->str_val) + 3;
+		result = calloc(len, 1);
+		snprintf(result, len, "_:%s", value->str_val);
+		break;
 	case SLV2_VALUE_STRING:
 	case SLV2_VALUE_QNAME_UNUSED:
 		result = strdup(value->str_val);
@@ -318,6 +327,21 @@ slv2_value_as_librdf_uri(SLV2Value value)
 
 
 bool
+slv2_value_is_blank(SLV2Value value)
+{
+	return (value && value->type == SLV2_VALUE_BLANK);
+}
+
+
+const char*
+slv2_value_as_blank(SLV2Value value)
+{
+	assert(slv2_value_is_blank(value));
+	return value->str_val;
+}
+
+
+bool
 slv2_value_is_literal(SLV2Value value)
 {
 	// No blank nodes