Use opaque node API

5 files changed, 82 insertions, 57 deletions

diff --git a/src/env.c b/src/env.c
index 9deb120b..954100fc 100644
--- a/src/env.c
+++ b/src/env.c
@@ -94,7 +94,7 @@ serd_env_find(const SerdEnv* env,
 	for (size_t i = 0; i < env->n_prefixes; ++i) {
 		const SerdNode* const prefix_name = &env->prefixes[i].name;
 		if (prefix_name->n_bytes == name_len) {
-			if (!memcmp(prefix_name->buf, name, name_len)) {
+			if (!memcmp(serd_node_get_string(prefix_name), name, name_len)) {
 				return &env->prefixes[i];
 			}
 		}
@@ -107,7 +107,8 @@ serd_env_add(SerdEnv*        env,
              const SerdNode* name,
              const SerdNode* uri)
 {
-	SerdPrefix* const prefix = serd_env_find(env, name->buf, name->n_bytes);
+	const char*       name_str = serd_node_get_string(name);
+	SerdPrefix* const prefix   = serd_env_find(env, name_str, name->n_bytes);
 	if (prefix) {
 		SerdNode old_prefix_uri = prefix->uri;
 		prefix->uri = serd_node_copy(uri);
@@ -127,7 +128,7 @@ serd_env_set_prefix(SerdEnv*        env,
 {
 	if (!name->buf || uri->type != SERD_URI) {
 		return SERD_ERR_BAD_ARG;
-	} else if (serd_uri_string_has_scheme(uri->buf)) {
+	} else if (serd_uri_string_has_scheme(serd_node_get_string(uri))) {
 		// Set prefix to absolute URI
 		serd_env_add(env, name, uri);
 	} else {
@@ -163,11 +164,12 @@ serd_env_qualify(const SerdEnv*  env,
 	for (size_t i = 0; i < env->n_prefixes; ++i) {
 		const SerdNode* const prefix_uri = &env->prefixes[i].uri;
 		if (uri->n_bytes >= prefix_uri->n_bytes) {
-			if (!strncmp((const char*)uri->buf,
-			             (const char*)prefix_uri->buf,
-			             prefix_uri->n_bytes)) {
+			const char* prefix_str = serd_node_get_string(prefix_uri);
+			const char* uri_str    = serd_node_get_string(uri);
+
+			if (!strncmp(uri_str, prefix_str, prefix_uri->n_bytes)) {
 				*prefix = env->prefixes[i].name;
-				suffix->buf = uri->buf + prefix_uri->n_bytes;
+				suffix->buf = uri_str + prefix_uri->n_bytes;
 				suffix->len = uri->n_bytes - prefix_uri->n_bytes;
 				return true;
 			}
@@ -182,16 +184,16 @@ serd_env_expand(const SerdEnv*  env,
                 SerdStringView* uri_prefix,
                 SerdStringView* uri_suffix)
 {
-	const char* const colon = (const char*)memchr(
-		curie->buf, ':', curie->n_bytes + 1);
+	const char* const str   = serd_node_get_string(curie);
+	const char* const colon = (const char*)memchr(str, ':', curie->n_bytes + 1);
 	if (curie->type != SERD_CURIE || !colon) {
 		return SERD_ERR_BAD_ARG;
 	}
 
-	const size_t            name_len = (size_t)(colon - curie->buf);
-	const SerdPrefix* const prefix   = serd_env_find(env, curie->buf, name_len);
+	const size_t            name_len = (size_t)(colon - str);
+	const SerdPrefix* const prefix   = serd_env_find(env, str, name_len);
 	if (prefix) {
-		uri_prefix->buf = prefix->uri.buf;
+		uri_prefix->buf = serd_node_get_string(&prefix->uri);
 		uri_prefix->len = prefix->uri.n_bytes;
 		uri_suffix->buf = colon + 1;
 		uri_suffix->len = curie->n_bytes - name_len - 1;
diff --git a/src/n3.c b/src/n3.c
index 4223961d..9239f67c 100644
--- a/src/n3.c
+++ b/src/n3.c
@@ -565,7 +565,8 @@ read_PN_PREFIX_tail(SerdReader* reader, Ref dest)
 	}
 
 	const SerdNode* const n = deref(reader, dest);
-	if (n->buf[n->n_bytes - 1] == '.' && read_PN_CHARS(reader, dest)) {
+	if (serd_node_get_string(n)[n->n_bytes - 1] == '.' &&
+	    read_PN_CHARS(reader, dest)) {
 		r_err(reader, SERD_ERR_BAD_SYNTAX, "prefix ends with `.'\n");
 		return SERD_ERR_BAD_SYNTAX;
 	}
@@ -839,7 +840,8 @@ read_verb(SerdReader* reader, Ref* dest)
 	bool             ate_dot = false;
 	SerdNode*        node    = deref(reader, *dest);
 	const int        next    = peek_byte(reader);
-	if (!st && node->n_bytes == 1 && node->buf[0] == 'a' &&
+	if (!st && node->n_bytes == 1 &&
+	    serd_node_get_string(node)[0] == 'a' &&
 	    next != ':' && !is_PN_CHARS_BASE((uint32_t)next)) {
 		pop_node(reader, *dest);
 		return (*dest = push_node(reader, SERD_URI, NS_RDF "type", 47));
@@ -878,8 +880,9 @@ read_BLANK_NODE_LABEL(SerdReader* reader, bool* ate_dot)
 		}
 	}
 
-	SerdNode* n = deref(reader, ref);
-	if (n->buf[n->n_bytes - 1] == '.' && read_PN_CHARS(reader, ref)) {
+	SerdNode* n   = deref(reader, ref);
+	char*     buf = serd_node_buffer(n);
+	if (buf[n->n_bytes - 1] == '.' && read_PN_CHARS(reader, ref)) {
 		// Ate trailing dot, pop it from stack/node and inform caller
 		--n->n_bytes;
 		serd_stack_pop(&reader->stack, 1);
@@ -887,12 +890,11 @@ read_BLANK_NODE_LABEL(SerdReader* reader, bool* ate_dot)
 	}
 
 	if (fancy_syntax(reader)) {
-		if (is_digit(n->buf[reader->bprefix_len + 1])) {
-			if ((n->buf[reader->bprefix_len]) == 'b') {
-				((char*)n->buf)[reader->bprefix_len] = 'B';  // Prevent clash
+		if (is_digit(buf[reader->bprefix_len + 1])) {
+			if ((buf[reader->bprefix_len]) == 'b') {
+				buf[reader->bprefix_len] = 'B';  // Prevent clash
 				reader->seen_genid = true;
-			} else if (reader->seen_genid &&
-			           n->buf[reader->bprefix_len] == 'B') {
+			} else if (reader->seen_genid && buf[reader->bprefix_len] == 'B') {
 				r_err(reader, SERD_ERR_ID_CLASH,
 				      "found both `b' and `B' blank IDs, prefix required\n");
 				return pop_node(reader, ref);
@@ -1022,8 +1024,10 @@ read_object(SerdReader* reader, ReadContext* ctx, bool emit, bool* ate_dot)
 		o = push_node(reader, SERD_CURIE, "", 0);
 		while (!read_PN_CHARS_BASE(reader, o)) {}
 		node = deref(reader, o);
-		if ((node->n_bytes == 4 && !memcmp(node->buf, "true", 4)) ||
-		    (node->n_bytes == 5 && !memcmp(node->buf, "false", 5))) {
+		if ((node->n_bytes == 4 &&
+		     !memcmp(serd_node_get_string(node), "true", 4)) ||
+		    (node->n_bytes == 5 &&
+		     !memcmp(serd_node_get_string(node), "false", 5))) {
 			node->type = SERD_LITERAL;
 			datatype   = push_node(
 				reader, SERD_URI, XSD_BOOLEAN, XSD_BOOLEAN_LEN);
@@ -1358,7 +1362,7 @@ tokcmp(SerdReader* reader, Ref ref, const char* tok, size_t n)
 	if (!node || node->n_bytes != n) {
 		return -1;
 	}
-	return serd_strncasecmp((const char*)node->buf, tok, n);
+	return serd_strncasecmp(serd_node_get_string(node), tok, n);
 }
 
 bool
diff --git a/src/node.c b/src/node.c
index 58f537f4..dfc31e5e 100644
--- a/src/node.c
+++ b/src/node.c
@@ -30,6 +30,12 @@
 #    endif
 #endif
 
+char*
+serd_node_buffer(SerdNode* node)
+{
+	return (char*)(node + 1);
+}
+
 SerdNode
 serd_node_from_string(SerdType type, const char* str)
 {
@@ -112,8 +118,9 @@ serd_node_new_uri_from_node(const SerdNode* uri_node,
                             const SerdURI*  base,
                             SerdURI*        out)
 {
-	return (uri_node->type == SERD_URI && uri_node->buf)
-		? serd_node_new_uri_from_string(uri_node->buf, base, out)
+	const char* uri_str = serd_node_get_string(uri_node);
+	return (uri_node->type == SERD_URI && uri_str)
+		? serd_node_new_uri_from_string(uri_str, base, out)
 		: SERD_NODE_NULL;
 }
 
@@ -379,13 +386,13 @@ serd_node_get_type(const SerdNode* node)
 const char*
 serd_node_get_string(const SerdNode* node)
 {
-	return node->buf;
+	return node ? node->buf : NULL;
 }
 
 size_t
 serd_node_get_length(const SerdNode* node)
 {
-	return node->n_bytes;
+	return node ? node->n_bytes : 0;
 }
 
 SerdNodeFlags
diff --git a/src/serd_internal.h b/src/serd_internal.h
index 211d260e..f8e82024 100644
--- a/src/serd_internal.h
+++ b/src/serd_internal.h
@@ -50,6 +50,8 @@
 
 static const uint8_t replacement_char[] = { 0xEF, 0xBF, 0xBD };
 
+char* serd_node_buffer(SerdNode* node);
+
 /* File and Buffer Utilities */
 
 static inline FILE*
diff --git a/src/writer.c b/src/writer.c
index a075f037..d781adb8 100644
--- a/src/writer.c
+++ b/src/writer.c
@@ -236,6 +236,12 @@ write_uri(SerdWriter* writer, const char* utf8, size_t n_bytes)
 	return len;
 }
 
+static size_t
+write_uri_from_node(SerdWriter* writer, const SerdNode* node)
+{
+	return write_uri(writer, serd_node_get_string(node), node->n_bytes);
+}
+
 static bool
 lname_must_escape(const char c)
 {
@@ -421,22 +427,23 @@ write_literal(SerdWriter*        writer,
               const SerdNode*    lang,
               SerdStatementFlags flags)
 {
-	if (supports_abbrev(writer) && datatype && datatype->buf) {
-		const char* type_uri = (const char*)datatype->buf;
+	const char* node_str = serd_node_get_string(node);
+	const char* type_uri = serd_node_get_string(datatype);
+	if (supports_abbrev(writer) && type_uri) {
 		if (!strncmp(type_uri, NS_XSD, sizeof(NS_XSD) - 1) && (
 			    !strcmp(type_uri + sizeof(NS_XSD) - 1, "boolean") ||
 			    !strcmp(type_uri + sizeof(NS_XSD) - 1, "integer"))) {
-			sink(node->buf, node->n_bytes, writer);
+			sink(node_str, node->n_bytes, writer);
 			return true;
 		} else if (!strncmp(type_uri, NS_XSD, sizeof(NS_XSD) - 1) &&
 		           !strcmp(type_uri + sizeof(NS_XSD) - 1, "decimal") &&
-		           strchr((const char*)node->buf, '.') &&
-		           node->buf[node->n_bytes - 1] != '.') {
+		           strchr(node_str, '.') &&
+		           node_str[node->n_bytes - 1] != '.') {
 			/* xsd:decimal literals without trailing digits, e.g. "5.", can
 			   not be written bare in Turtle.  We could add a 0 which is
 			   prettier, but changes the text and breaks round tripping.
 			*/
-			sink(node->buf, node->n_bytes, writer);
+			sink(node_str, node->n_bytes, writer);
 			return true;
 		}
 	}
@@ -444,17 +451,17 @@ write_literal(SerdWriter*        writer,
 	if (supports_abbrev(writer)
 	    && (node->flags & (SERD_HAS_NEWLINE|SERD_HAS_QUOTE))) {
 		sink("\"\"\"", 3, writer);
-		write_text(writer, WRITE_LONG_STRING, node->buf, node->n_bytes);
+		write_text(writer, WRITE_LONG_STRING, node_str, node->n_bytes);
 		sink("\"\"\"", 3, writer);
 	} else {
 		sink("\"", 1, writer);
-		write_text(writer, WRITE_STRING, node->buf, node->n_bytes);
+		write_text(writer, WRITE_STRING, node_str, node->n_bytes);
 		sink("\"", 1, writer);
 	}
-	if (lang && lang->buf) {
+	if (lang && serd_node_get_string(lang)) {
 		sink("@", 1, writer);
-		sink(lang->buf, lang->n_bytes, writer);
-	} else if (datatype && datatype->buf) {
+		sink(serd_node_get_string(lang), lang->n_bytes, writer);
+	} else if (type_uri) {
 		sink("^^", 2, writer);
 		return write_node(writer, datatype, NULL, NULL, FIELD_NONE, flags);
 	}
@@ -489,17 +496,17 @@ write_uri_node(SerdWriter* const        writer,
 		sink("== ", 3, writer);
 	}
 
-	const bool has_scheme = serd_uri_string_has_scheme(node->buf);
+	const char* node_str   = serd_node_get_string(node);
+	const bool  has_scheme = serd_uri_string_has_scheme(node_str);
 	if (field == FIELD_PREDICATE && supports_abbrev(writer)
-	    && !strcmp((const char*)node->buf, NS_RDF "type")) {
+	    && !strcmp(node_str, NS_RDF "type")) {
 		return sink("a", 1, writer) == 1;
-	} else if (supports_abbrev(writer)
-	           && !strcmp((const char*)node->buf, NS_RDF "nil")) {
+	} else if (supports_abbrev(writer) && !strcmp(node_str, NS_RDF "nil")) {
 		return sink("()", 2, writer) == 2;
 	} else if (has_scheme && (writer->style & SERD_STYLE_CURIED) &&
 	           serd_env_qualify(writer->env, node, &prefix, &suffix) &&
 	           is_name(suffix.buf, suffix.len)) {
-		write_uri(writer, prefix.buf, prefix.n_bytes);
+		write_uri_from_node(writer, &prefix);
 		sink(":", 1, writer);
 		write_uri(writer, suffix.buf, suffix.len);
 		return true;
@@ -509,7 +516,7 @@ write_uri_node(SerdWriter* const        writer,
 	if (writer->style & SERD_STYLE_RESOLVED) {
 		SerdURI in_base_uri, uri, abs_uri;
 		serd_env_get_base_uri(writer->env, &in_base_uri);
-		serd_uri_parse(node->buf, &uri);
+		serd_uri_parse(node_str, &uri);
 		serd_uri_resolve(&uri, &in_base_uri, &abs_uri);
 		bool rooted = uri_is_under(&writer->base_uri, &writer->root_uri);
 		SerdURI* root = rooted ? &writer->root_uri : & writer->base_uri;
@@ -522,7 +529,7 @@ write_uri_node(SerdWriter* const        writer,
 				&uri, &writer->base_uri, root, uri_sink, writer);
 		}
 	} else {
-		write_uri(writer, node->buf, node->n_bytes);
+		write_uri_from_node(writer, node);
 	}
 	write_sep(writer, SEP_URI_END);
 	if (is_inline_start(writer, field, flags)) {
@@ -538,6 +545,8 @@ write_curie(SerdWriter* const        writer,
             const Field              field,
             const SerdStatementFlags flags)
 {
+	const char* node_str = serd_node_get_string(node);
+
 	SerdStringView prefix;
 	SerdStringView suffix;
 	SerdStatus     st;
@@ -545,7 +554,7 @@ write_curie(SerdWriter* const        writer,
 	case SERD_NTRIPLES:
 	case SERD_NQUADS:
 		if ((st = serd_env_expand(writer->env, node, &prefix, &suffix))) {
-			w_err(writer, st, "undefined namespace prefix `%s'\n", node->buf);
+			w_err(writer, st, "undefined namespace prefix `%s'\n", node_str);
 			return false;
 		}
 		write_sep(writer, SEP_URI_BEGIN);
@@ -560,7 +569,7 @@ write_curie(SerdWriter* const        writer,
 			write_sep(writer, SEP_ANON_BEGIN);
 			sink("== ", 3, writer);
 		}
-		write_lname(writer, node->buf, node->n_bytes);
+		write_lname(writer, node_str, node->n_bytes);
 		if (is_inline_start(writer, field, flags)) {
 			sink(" ;", 2, writer);
 			write_newline(writer);
@@ -575,6 +584,7 @@ write_blank(SerdWriter* const        writer,
             const Field              field,
             const SerdStatementFlags flags)
 {
+	const char* node_str = serd_node_get_string(node);
 	if (supports_abbrev(writer)) {
 		if (is_inline_start(writer, field, flags)) {
 			++writer->indent;
@@ -597,12 +607,12 @@ write_blank(SerdWriter* const        writer,
 
 	sink("_:", 2, writer);
 	if (writer->bprefix &&
-	    !strncmp(node->buf, writer->bprefix, writer->bprefix_len)) {
-		sink(node->buf + writer->bprefix_len,
+	    !strncmp(node_str, writer->bprefix, writer->bprefix_len)) {
+		sink(node_str + writer->bprefix_len,
 		     node->n_bytes - writer->bprefix_len,
 		     writer);
 	} else {
-		sink(node->buf, node->n_bytes, writer);
+		sink(node_str, node->n_bytes, writer);
 	}
 
 	return true;
@@ -657,11 +667,11 @@ write_list_obj(SerdWriter*        writer,
                const SerdNode*    datatype,
                const SerdNode*    lang)
 {
-	if (!strcmp((const char*)object->buf, NS_RDF "nil")) {
+	if (!strcmp(serd_node_get_string(object), NS_RDF "nil")) {
 		--writer->indent;
 		write_sep(writer, SEP_LIST_END);
 		return true;
-	} else if (!strcmp((const char*)predicate->buf, NS_RDF "first")) {
+	} else if (!strcmp(serd_node_get_string(predicate), NS_RDF "first")) {
 		write_sep(writer, SEP_LIST_SEP);
 		write_node(writer, object, datatype, lang, FIELD_OBJECT, flags);
 	}
@@ -904,7 +914,7 @@ serd_writer_set_base_uri(SerdWriter*     writer,
 				reset_context(writer, true);
 			}
 			sink("@base <", 7, writer);
-			sink(uri->buf, uri->n_bytes, writer);
+			sink(serd_node_get_string(uri), uri->n_bytes, writer);
 			sink("> .\n", 4, writer);
 		}
 		writer->indent = 0;
@@ -920,7 +930,7 @@ serd_writer_set_root_uri(SerdWriter*     writer,
 	serd_node_free(&writer->root_node);
 	if (uri && uri->buf) {
 		writer->root_node = serd_node_copy(uri);
-		serd_uri_parse(uri->buf, &writer->root_uri);
+		serd_uri_parse(serd_node_get_string(uri), &writer->root_uri);
 	} else {
 		writer->root_node = SERD_NODE_NULL;
 		writer->root_uri  = SERD_URI_NULL;
@@ -940,9 +950,9 @@ serd_writer_set_prefix(SerdWriter*     writer,
 				reset_context(writer, true);
 			}
 			sink("@prefix ", 8, writer);
-			sink(name->buf, name->n_bytes, writer);
+			sink(serd_node_get_string(name), name->n_bytes, writer);
 			sink(": <", 3, writer);
-			write_uri(writer, uri->buf, uri->n_bytes);
+			write_uri_from_node(writer, uri);
 			sink("> .\n", 4, writer);
 		}
 		writer->indent = 0;