Make nodes opaque

9 files changed, 468 insertions, 404 deletions

diff --git a/NEWS b/NEWS
index 9180a935..5c9dfe62 100644
--- a/NEWS
+++ b/NEWS
@@ -1,6 +1,8 @@
 serd (1.0.1) unstable;
 
   * Add SerdBuffer for mutable buffers to keep SerdChunk const-correct
+  * Make nodes opaque
+  * Make serd_strtod API const-correct
   * Make serd_strtod API const-correct
   * Remove useless character counting from API
   * Rename SerdChunk to SerdStringView
diff --git a/serd/serd.h b/serd/serd.h
index c4bb0381..288a62fa 100644
--- a/serd/serd.h
+++ b/serd/serd.h
@@ -213,12 +213,7 @@ typedef uint32_t SerdNodeFlags;
 /**
    A syntactic RDF node.
 */
-typedef struct {
-	const char*    buf;      /**< Value string */
-	size_t         n_bytes;  /**< Size in bytes (not including null) */
-	SerdNodeFlags  flags;    /**< Node flags (e.g. string properties) */
-	SerdType       type;     /**< Node type */
-} SerdNode;
+typedef struct SerdNodeImpl SerdNode;
 
 /**
    An unterminated immutable slice of a string.
@@ -461,32 +456,25 @@ serd_uri_serialise_relative(const SerdURI* uri,
    @{
 */
 
-static const SerdNode SERD_NODE_NULL = { NULL, 0, 0, SERD_NOTHING };
-
 /**
-   Make a (shallow) node from `str`.
-
-   This measures, but does not copy, `str`.  No memory is allocated.
+   Create a new node from `str`.
 */
 SERD_API
-SerdNode
-serd_node_from_string(SerdType type, const char* str);
+SerdNode*
+serd_node_new_string(SerdType type, const char* str);
 
 /**
-   Make a (shallow) node from a prefix of `str`.
-
-   This measures, but does not copy, `str`.  No memory is allocated.
-   Note that the returned node may not be null terminated.
+   Create a new node from a prefix of `str`.
 */
 SERD_API
-SerdNode
-serd_node_from_substring(SerdType type, const char* str, size_t len);
+SerdNode*
+serd_node_new_substring(SerdType type, const char* str, size_t len);
 
 /**
    Simple wrapper for serd_node_new_uri() to resolve a URI node.
 */
 SERD_API
-SerdNode
+SerdNode*
 serd_node_new_uri_from_node(const SerdNode* uri_node,
                             const SerdURI*  base,
                             SerdURI*        out);
@@ -495,7 +483,7 @@ serd_node_new_uri_from_node(const SerdNode* uri_node,
    Simple wrapper for serd_node_new_uri() to resolve a URI string.
 */
 SERD_API
-SerdNode
+SerdNode*
 serd_node_new_uri_from_string(const char*    str,
                               const SerdURI* base,
                               SerdURI*       out);
@@ -511,7 +499,7 @@ serd_node_new_uri_from_string(const char*    str,
    If `out` is not NULL, it will be set to the parsed URI.
 */
 SERD_API
-SerdNode
+SerdNode*
 serd_node_new_file_uri(const char* path,
                        const char* hostname,
                        SerdURI*    out,
@@ -528,7 +516,7 @@ serd_node_new_file_uri(const char* path,
    memory owned by the new returned node).
 */
 SERD_API
-SerdNode
+SerdNode*
 serd_node_new_uri(const SerdURI* uri, const SerdURI* base, SerdURI* out);
 
 /**
@@ -544,7 +532,7 @@ serd_node_new_uri(const SerdURI* uri, const SerdURI* base, SerdURI* out);
    memory owned by the new returned node).
 */
 SERD_API
-SerdNode
+SerdNode*
 serd_node_new_relative_uri(const SerdURI* uri,
                            const SerdURI* base,
                            const SerdURI* root,
@@ -566,14 +554,14 @@ serd_node_new_relative_uri(const SerdURI* uri,
    @param frac_digits The maximum number of digits after the decimal place.
 */
 SERD_API
-SerdNode
+SerdNode*
 serd_node_new_decimal(double d, unsigned frac_digits);
 
 /**
    Create a new node by serialising `i` into an xsd:integer string.
 */
 SERD_API
-SerdNode
+SerdNode*
 serd_node_new_integer(int64_t i);
 
 /**
@@ -586,19 +574,24 @@ serd_node_new_integer(int64_t i);
    @param wrap_lines Wrap lines at 76 characters to conform to RFC 2045.
 */
 SERD_API
-SerdNode
+SerdNode*
 serd_node_new_blob(const void* buf, size_t size, bool wrap_lines);
 
 /**
-   Make a deep copy of `node`.
-
-   @return a node that the caller must free with serd_node_free().
+   Return a deep copy of `node`.
 */
 SERD_API
-SerdNode
+SerdNode*
 serd_node_copy(const SerdNode* node);
 
 /**
+   Free any data owned by `node`.
+*/
+SERD_API
+void
+serd_node_free(SerdNode* node);
+
+/**
    Return the type of a node (SERD_URI, SERD_BLANK, or SERD_LITERAL).
 */
 SERD_API
@@ -634,16 +627,6 @@ bool
 serd_node_equals(const SerdNode* a, const SerdNode* b);
 
 /**
-   Free any data owned by `node`.
-
-   Note that if `node` is itself dynamically allocated (which is not the case
-   for nodes created internally by serd), it will not be freed.
-*/
-SERD_API
-void
-serd_node_free(SerdNode* node);
-
-/**
    @}
    @name Event Handlers
    @{
@@ -758,10 +741,10 @@ serd_env_set_prefix_from_strings(SerdEnv*    env,
 */
 SERD_API
 bool
-serd_env_qualify(const SerdEnv*  env,
-                 const SerdNode* uri,
-                 SerdNode*       prefix,
-                 SerdStringView* suffix);
+serd_env_qualify(const SerdEnv*   env,
+                 const SerdNode*  uri,
+                 const SerdNode** prefix,
+                 SerdStringView*  suffix);
 
 /**
    Expand `curie`.
@@ -782,7 +765,7 @@ serd_env_expand(const SerdEnv*  env,
    Returns null if `node` can not be expanded.
 */
 SERD_API
-SerdNode
+SerdNode*
 serd_env_expand_node(const SerdEnv*  env,
                      const SerdNode* node);
 
diff --git a/src/env.c b/src/env.c
index 292f047c..585332d7 100644
--- a/src/env.c
+++ b/src/env.c
@@ -14,6 +14,8 @@
   OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
 
+#include "serd_internal.h"
+
 #include "serd/serd.h"
 
 #include <stdbool.h>
@@ -22,14 +24,14 @@
 #include <string.h>
 
 typedef struct {
-	SerdNode name;
-	SerdNode uri;
+	SerdNode* name;
+	SerdNode* uri;
 } SerdPrefix;
 
 struct SerdEnvImpl {
 	SerdPrefix* prefixes;
 	size_t      n_prefixes;
-	SerdNode    base_uri_node;
+	SerdNode*   base_uri_node;
 	SerdURI     base_uri;
 };
 
@@ -47,11 +49,11 @@ void
 serd_env_free(SerdEnv* env)
 {
 	for (size_t i = 0; i < env->n_prefixes; ++i) {
-		serd_node_free(&env->prefixes[i].name);
-		serd_node_free(&env->prefixes[i].uri);
+		serd_node_free(env->prefixes[i].name);
+		serd_node_free(env->prefixes[i].uri);
 	}
 	free(env->prefixes);
-	serd_node_free(&env->base_uri_node);
+	serd_node_free(env->base_uri_node);
 	free(env);
 }
 
@@ -62,7 +64,7 @@ serd_env_get_base_uri(const SerdEnv* env,
 	if (out) {
 		*out = env->base_uri;
 	}
-	return &env->base_uri_node;
+	return env->base_uri_node;
 }
 
 SerdStatus
@@ -74,13 +76,13 @@ serd_env_set_base_uri(SerdEnv*        env,
 	}
 
 	// Resolve base URI and create a new node and URI for it
-	SerdURI  base_uri;
-	SerdNode base_uri_node = serd_node_new_uri_from_node(
+	SerdURI   base_uri;
+	SerdNode* base_uri_node = serd_node_new_uri_from_node(
 		uri, &env->base_uri, &base_uri);
 
-	if (base_uri_node.buf) {
+	if (base_uri_node) {
 		// Replace the current base URI
-		serd_node_free(&env->base_uri_node);
+		serd_node_free(env->base_uri_node);
 		env->base_uri_node = base_uri_node;
 		env->base_uri      = base_uri;
 		return SERD_SUCCESS;
@@ -94,7 +96,7 @@ serd_env_find(const SerdEnv* env,
               size_t         name_len)
 {
 	for (size_t i = 0; i < env->n_prefixes; ++i) {
-		const SerdNode* const prefix_name = &env->prefixes[i].name;
+		const SerdNode* const prefix_name = env->prefixes[i].name;
 		if (prefix_name->n_bytes == name_len) {
 			if (!memcmp(serd_node_get_string(prefix_name), name, name_len)) {
 				return &env->prefixes[i];
@@ -112,9 +114,9 @@ serd_env_add(SerdEnv*        env,
 	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;
+		SerdNode* old_prefix_uri = prefix->uri;
 		prefix->uri = serd_node_copy(uri);
-		serd_node_free(&old_prefix_uri);
+		serd_node_free(old_prefix_uri);
 	} else {
 		env->prefixes = (SerdPrefix*)realloc(
 			env->prefixes, (++env->n_prefixes) * sizeof(SerdPrefix));
@@ -128,20 +130,20 @@ serd_env_set_prefix(SerdEnv*        env,
                     const SerdNode* name,
                     const SerdNode* uri)
 {
-	if (!name->buf || uri->type != SERD_URI) {
+	if (!name || uri->type != SERD_URI) {
 		return SERD_ERR_BAD_ARG;
 	} else if (serd_uri_string_has_scheme(serd_node_get_string(uri))) {
 		// Set prefix to absolute URI
 		serd_env_add(env, name, uri);
 	} else {
 		// Resolve relative URI and create a new node and URI for it
-		SerdURI  abs_uri;
-		SerdNode abs_uri_node = serd_node_new_uri_from_node(
+		SerdURI   abs_uri;
+		SerdNode* abs_uri_node = serd_node_new_uri_from_node(
 			uri, &env->base_uri, &abs_uri);
 
 		// Set prefix to resolved (absolute) URI
-		serd_env_add(env, name, &abs_uri_node);
-		serd_node_free(&abs_uri_node);
+		serd_env_add(env, name, abs_uri_node);
+		serd_node_free(abs_uri_node);
 	}
 	return SERD_SUCCESS;
 }
@@ -151,20 +153,24 @@ serd_env_set_prefix_from_strings(SerdEnv*    env,
                                  const char* name,
                                  const char* uri)
 {
-	const SerdNode name_node = serd_node_from_string(SERD_LITERAL, name);
-	const SerdNode uri_node  = serd_node_from_string(SERD_URI, uri);
+	SerdNode* name_node = serd_node_new_string(SERD_LITERAL, name);
+	SerdNode* uri_node  = serd_node_new_string(SERD_URI, uri);
+
+	const SerdStatus st = serd_env_set_prefix(env, name_node, uri_node);
 
-	return serd_env_set_prefix(env, &name_node, &uri_node);
+	serd_node_free(name_node);
+	serd_node_free(uri_node);
+	return st;
 }
 
 bool
-serd_env_qualify(const SerdEnv*  env,
-                 const SerdNode* uri,
-                 SerdNode*       prefix,
-                 SerdStringView* suffix)
+serd_env_qualify(const SerdEnv*   env,
+                 const SerdNode*  uri,
+                 const SerdNode** prefix,
+                 SerdStringView*  suffix)
 {
 	for (size_t i = 0; i < env->n_prefixes; ++i) {
-		const SerdNode* const prefix_uri = &env->prefixes[i].uri;
+		const SerdNode* const prefix_uri = env->prefixes[i].uri;
 		if (uri->n_bytes >= prefix_uri->n_bytes) {
 			const char* prefix_str = serd_node_get_string(prefix_uri);
 			const char* uri_str    = serd_node_get_string(uri);
@@ -195,8 +201,8 @@ serd_env_expand(const SerdEnv*  env,
 	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 = serd_node_get_string(&prefix->uri);
-		uri_prefix->len = prefix->uri.n_bytes;
+		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;
 		return SERD_SUCCESS;
@@ -204,7 +210,7 @@ serd_env_expand(const SerdEnv*  env,
 	return SERD_ERR_BAD_CURIE;
 }
 
-SerdNode
+SerdNode*
 serd_env_expand_node(const SerdEnv*  env,
                      const SerdNode* node)
 {
@@ -213,12 +219,13 @@ serd_env_expand_node(const SerdEnv*  env,
 		SerdStringView prefix;
 		SerdStringView suffix;
 		if (serd_env_expand(env, node, &prefix, &suffix)) {
-			return SERD_NODE_NULL;
+			return NULL;
 		}
 		const size_t len = prefix.len + suffix.len;
-		char*        buf = (char*)malloc(len + 1);
-		SerdNode     ret = { buf, len, 0, SERD_URI };
-		snprintf(buf, ret.n_bytes + 1, "%s%s", prefix.buf, suffix.buf);
+		SerdNode*    ret = serd_node_malloc(len, 0, SERD_URI);
+		char*        buf = serd_node_buffer(ret);
+		snprintf(buf, len + 1, "%s%s", prefix.buf, suffix.buf);
+		ret->n_bytes = len;
 		return ret;
 	}
 	case SERD_URI: {
@@ -226,7 +233,7 @@ serd_env_expand_node(const SerdEnv*  env,
 		return serd_node_new_uri_from_node(node, &env->base_uri, &ignored);
 	}
 	default:
-		return SERD_NODE_NULL;
+		return NULL;
 	}
 }
 
@@ -236,6 +243,6 @@ serd_env_foreach(const SerdEnv* env,
                  void*          handle)
 {
 	for (size_t i = 0; i < env->n_prefixes; ++i) {
-		func(handle, &env->prefixes[i].name, &env->prefixes[i].uri);
+		func(handle, env->prefixes[i].name, env->prefixes[i].uri);
 	}
 }
diff --git a/src/node.c b/src/node.c
index e09ca232..2e792fb8 100644
--- a/src/node.c
+++ b/src/node.c
@@ -35,59 +35,87 @@
 #    endif
 #endif
 
+SerdNode*
+serd_node_malloc(size_t n_bytes, SerdNodeFlags flags, SerdType type)
+{
+	SerdNode* node = (SerdNode*)calloc(1, sizeof(SerdNode) + n_bytes + 1);
+	node->n_bytes = 0;
+	node->flags   = flags;
+	node->type    = type;
+	return node;
+}
+
 char*
 serd_node_buffer(SerdNode* node)
 {
 	return (char*)(node + 1);
 }
 
-SerdNode
-serd_node_from_string(SerdType type, const char* str)
+void
+serd_node_set(SerdNode** dst, const SerdNode* src)
+{
+	if (src) {
+		if (!(*dst) || (*dst)->n_bytes < src->n_bytes) {
+			(*dst) = (SerdNode*)realloc(*dst, sizeof(SerdNode) + src->n_bytes + 1);
+		}
+
+		memcpy(*dst, src, sizeof(SerdNode) + src->n_bytes + 1);
+	} else if (*dst) {
+		memset(*dst, 0, sizeof(SerdNode));
+	}
+}
+
+SerdNode*
+serd_node_new_string(SerdType type, const char* str)
 {
 	if (!str) {
-		return SERD_NODE_NULL;
+		return NULL;
 	}
 
-	uint32_t       flags   = 0;
-	const size_t   n_bytes = serd_strlen(str, &flags);
-	const SerdNode ret     = { str, n_bytes, flags, type };
-	return ret;
+	uint32_t     flags   = 0;
+	const size_t n_bytes = serd_strlen(str, &flags);
+	SerdNode*    node    = serd_node_malloc(n_bytes, flags, type);
+	memcpy(serd_node_buffer(node), str, n_bytes);
+	node->n_bytes = n_bytes;
+	return node;
 }
 
-SerdNode
-serd_node_from_substring(SerdType type, const char* str, const size_t len)
+SerdNode*
+serd_node_new_substring(SerdType type, const char* str, const size_t len)
 {
 	if (!str) {
-		return SERD_NODE_NULL;
+		return NULL;
 	}
 
-	uint32_t       flags   = 0;
-	const size_t   n_bytes = serd_substrlen(str, len, &flags);
-	const SerdNode ret     = { str, n_bytes, flags, type };
-	return ret;
+	uint32_t     flags   = 0;
+	const size_t n_bytes = serd_substrlen(str, len, &flags);
+	SerdNode*    node    = serd_node_malloc(n_bytes, flags, type);
+	memcpy(serd_node_buffer(node), str, n_bytes);
+	node->n_bytes = n_bytes;
+	return node;
 }
 
-SerdNode
+SerdNode*
 serd_node_copy(const SerdNode* node)
 {
-	if (!node || !node->buf) {
-		return SERD_NODE_NULL;
+	if (!node) {
+		return NULL;
 	}
 
-	SerdNode copy = *node;
-	char* buf  = (char*)malloc(copy.n_bytes + 1);
-	memcpy(buf, node->buf, copy.n_bytes + 1);
-	copy.buf = buf;
+	const size_t size = sizeof(SerdNode) + node->n_bytes + 1;
+	SerdNode*    copy = (SerdNode*)malloc(size);
+	memcpy(copy, node, size);
 	return copy;
 }
 
 bool
 serd_node_equals(const SerdNode* a, const SerdNode* b)
 {
-	return (a == b)
-		|| (a->type == b->type
-		    && a->n_bytes == b->n_bytes
-		    && ((a->buf == b->buf) || !memcmp(a->buf, b->buf, a->n_bytes + 1)));
+	return (a == b) ||
+	       (a && b && a->type == b->type && a->n_bytes == b->n_bytes &&
+	        !memcmp(serd_node_get_string(a),
+	                serd_node_get_string(b),
+	                a->n_bytes));
 }
 
 static size_t
@@ -116,7 +144,7 @@ string_sink(const void* buf, size_t len, void* stream)
 	return len;
 }
 
-SerdNode
+SerdNode*
 serd_node_new_uri_from_node(const SerdNode* uri_node,
                             const SerdURI*  base,
                             SerdURI*        out)
@@ -124,17 +152,17 @@ serd_node_new_uri_from_node(const SerdNode* uri_node,
 	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;
+		: NULL;
 }
 
-SerdNode
+SerdNode*
 serd_node_new_uri_from_string(const char*    str,
                               const SerdURI* base,
                               SerdURI*       out)
 {
 	if (!str || str[0] == '\0') {
 		// Empty URI => Base URI, or nothing if no base is given
-		return base ? serd_node_new_uri(base, NULL, out) : SERD_NODE_NULL;
+		return base ? serd_node_new_uri(base, NULL, out) : NULL;
 	}
 
 	SerdURI uri;
@@ -161,7 +189,7 @@ is_uri_path_char(const char c)
 	}
 }
 
-SerdNode
+SerdNode*
 serd_node_new_file_uri(const char* path,
                        const char* hostname,
                        SerdURI*    out,
@@ -196,15 +224,17 @@ serd_node_new_file_uri(const char* path,
 	}
 	serd_buffer_sink_finish(&buffer);
 
+	SerdNode* node = serd_node_new_substring(
+		SERD_URI, (const char*)buffer.buf, buffer.len);
 	if (out) {
-		serd_uri_parse((const char*)buffer.buf, out);
+		serd_uri_parse(serd_node_buffer(node), out);
 	}
 
-	return serd_node_from_substring(
-		SERD_URI, (const char*)buffer.buf, buffer.len);
+	free(buffer.buf);
+	return node;
 }
 
-SerdNode
+SerdNode*
 serd_node_new_uri(const SerdURI* uri, const SerdURI* base, SerdURI* out)
 {
 	SerdURI abs_uri = *uri;
@@ -213,22 +243,21 @@ serd_node_new_uri(const SerdURI* uri, const SerdURI* base, SerdURI* out)
 	}
 
 	const size_t len        = serd_uri_string_length(&abs_uri);
-	char*        buf        = (char*)malloc(len + 1);
-	SerdNode     node       = { buf, len, 0, SERD_URI };
-	char*        ptr        = buf;
+	SerdNode*    node       = serd_node_malloc(len, 0, SERD_URI);
+	char*        ptr        = serd_node_buffer(node);
 	const size_t actual_len = serd_uri_serialise(&abs_uri, string_sink, &ptr);
 
-	buf[actual_len] = '\0';
-	node.n_bytes    = actual_len;
+	serd_node_buffer(node)[actual_len] = '\0';
+	node->n_bytes = actual_len;
 
 	if (out) {
-		serd_uri_parse(buf, out);  // TODO: cleverly avoid double parse
+		serd_uri_parse(serd_node_buffer(node), out);  // TODO: avoid double parse
 	}
 
 	return node;
 }
 
-SerdNode
+SerdNode*
 serd_node_new_relative_uri(const SerdURI* uri,
                            const SerdURI* base,
                            const SerdURI* root,
@@ -236,17 +265,16 @@ serd_node_new_relative_uri(const SerdURI* uri,
 {
 	const size_t uri_len    = serd_uri_string_length(uri);
 	const size_t base_len   = serd_uri_string_length(base);
-	char*        buf        = (char*)malloc(uri_len + base_len + 1);
-	SerdNode     node       = { buf, 0, 0, SERD_URI };
-	char*        ptr        = buf;
+	SerdNode*    node       = serd_node_malloc(uri_len + base_len, 0, SERD_URI);
+	char*        ptr        = serd_node_buffer(node);
 	const size_t actual_len = serd_uri_serialise_relative(
 		uri, base, root, string_sink, &ptr);
 
-	buf[actual_len] = '\0';
-	node.n_bytes    = actual_len;
+	serd_node_buffer(node)[actual_len] = '\0';
+	node->n_bytes = actual_len;
 
 	if (out) {
-		serd_uri_parse(buf, out);  // TODO: cleverly avoid double parse
+		serd_uri_parse(serd_node_buffer(node), out);  // TODO: avoid double parse
 	}
 
 	return node;
@@ -259,18 +287,19 @@ serd_digits(double abs)
 	return lg < 1.0 ? 1U : (unsigned)lg;
 }
 
-SerdNode
+SerdNode*
 serd_node_new_decimal(double d, unsigned frac_digits)
 {
 	if (isnan(d) || isinf(d)) {
-		return SERD_NODE_NULL;
+		return NULL;
 	}
 
-	const double   abs_d      = fabs(d);
-	const unsigned int_digits = serd_digits(abs_d);
-	char*          buf        = (char*)calloc(int_digits + frac_digits + 3, 1);
-	SerdNode       node       = { buf, 0, 0, SERD_LITERAL };
-	const double   int_part   = floor(abs_d);
+	const double    abs_d      = fabs(d);
+	const unsigned  int_digits = serd_digits(abs_d);
+	const size_t    len        = int_digits + frac_digits + 3;
+	SerdNode* const node       = serd_node_malloc(len, 0, SERD_LITERAL);
+	char* const     buf        = serd_node_buffer(node);
+	const double    int_part   = floor(abs_d);
 
 	// Point s to decimal point location
 	char* s = buf + int_digits;
@@ -286,13 +315,14 @@ serd_node_new_decimal(double d, unsigned frac_digits)
 		*t-- = (char)('0' + dec % 10);
 	} while ((dec /= 10) > 0);
 
+
 	*s++ = '.';
 
 	// Write fractional part (right to left)
 	double frac_part = fabs(d - int_part);
 	if (frac_part < DBL_EPSILON) {
 		*s++ = '0';
-		node.n_bytes = (size_t)(s - buf);
+		node->n_bytes = (size_t)(s - buf);
 	} else {
 		uint64_t frac = (uint64_t)llround(frac_part * pow(10.0, (int)frac_digits));
 		s += frac_digits - 1;
@@ -301,7 +331,7 @@ serd_node_new_decimal(double d, unsigned frac_digits)
 		// Skip trailing zeros
 		for (; i < frac_digits - 1 && !(frac % 10); ++i, --s, frac /= 10) {}
 
-		node.n_bytes = (size_t)(s - buf) + 1u;
+		node->n_bytes = (size_t)(s - buf) + 1u;
 
 		// Write digits from last trailing zero to decimal point
 		for (; i < frac_digits; ++i) {
@@ -313,13 +343,13 @@ serd_node_new_decimal(double d, unsigned frac_digits)
 	return node;
 }
 
-SerdNode
+SerdNode*
 serd_node_new_integer(int64_t i)
 {
 	int64_t        abs_i  = (i < 0) ? -i : i;
 	const unsigned digits = serd_digits((double)abs_i);
-	char*          buf    = (char*)calloc(digits + 2, 1);
-	SerdNode       node   = { (const char*)buf, 0, 0, SERD_LITERAL };
+	SerdNode*      node   = serd_node_malloc(digits + 2, 0, SERD_LITERAL);
+	char*          buf    = serd_node_buffer(node);
 
 	// Point s to the end
 	char* s = buf + digits - 1;
@@ -328,7 +358,7 @@ serd_node_new_integer(int64_t i)
 		++s;
 	}
 
-	node.n_bytes = (size_t)(s - buf) + 1u;
+	node->n_bytes = (size_t)(s - buf) + 1u;
 
 	// Write integer part (right to left)
 	do {
@@ -359,12 +389,16 @@ encode_chunk(uint8_t out[4], const uint8_t in[3], size_t n_in)
 	out[3] = ((n_in > 2) ? b64_map[in[2] & 0x3F] : (uint8_t)'=');
 }
 
-SerdNode
+SerdNode*
 serd_node_new_blob(const void* buf, size_t size, bool wrap_lines)
 {
+	if (!buf || !size) {
+		return NULL;
+	}
+
 	const size_t len  = (size + 2) / 3 * 4 + (wrap_lines * ((size - 1) / 57));
-	uint8_t*     str  = (uint8_t*)calloc(len + 2, 1);
-	SerdNode     node = { (const char*)str, len, 0, SERD_LITERAL };
+	SerdNode*    node = serd_node_malloc(len + 1, 0, SERD_LITERAL);
+	uint8_t*     str  = (uint8_t*)serd_node_buffer(node);
 	for (size_t i = 0, j = 0; i < size; i += 3, j += 4) {
 		uint8_t in[4] = { 0, 0, 0, 0 };
 		size_t  n_in  = MIN(3, size - i);
@@ -372,11 +406,12 @@ serd_node_new_blob(const void* buf, size_t size, bool wrap_lines)
 
 		if (wrap_lines && i > 0 && (i % 57) == 0) {
 			str[j++] = '\n';
-			node.flags |= SERD_HAS_NEWLINE;
+			node->flags |= SERD_HAS_NEWLINE;
 		}
 
 		encode_chunk(str + j, in, n_in);
 	}
+	node->n_bytes = len;
 	return node;
 }
 
@@ -389,7 +424,7 @@ serd_node_get_type(const SerdNode* node)
 const char*
 serd_node_get_string(const SerdNode* node)
 {
-	return node ? node->buf : NULL;
+	return node ? (const char*)(node + 1) : NULL;
 }
 
 size_t
@@ -407,8 +442,5 @@ serd_node_get_flags(const SerdNode* node)
 void
 serd_node_free(SerdNode* node)
 {
-	if (node && node->buf) {
-		free((char*)node->buf);
-		node->buf = NULL;
-	}
+	free(node);
 }
diff --git a/src/reader.c b/src/reader.c
index ea1f2e65..3d20eef3 100644
--- a/src/reader.c
+++ b/src/reader.c
@@ -40,9 +40,11 @@ void
 set_blank_id(SerdReader* reader, Ref ref, size_t buf_size)
 {
 	SerdNode*   node   = deref(reader, ref);
+	char*       buf    = (char*)(node + 1);
 	const char* prefix = reader->bprefix ? (const char*)reader->bprefix : "";
-	node->n_bytes = (size_t)snprintf(
-		(char*)node->buf, buf_size, "%sb%u", prefix, reader->next_id++);
+
+	node->n_bytes =
+		(size_t)snprintf(buf, buf_size, "%sb%u", prefix, reader->next_id++);
 }
 
 size_t
@@ -86,7 +88,6 @@ push_node_padded(SerdReader* reader, size_t maxlen,
 	node->n_bytes = n_bytes;
 	node->flags   = 0;
 	node->type    = type;
-	node->buf     = NULL;
 
 	char* buf = (char*)(node + 1);
 	memcpy(buf, str, n_bytes + 1);
@@ -108,12 +109,7 @@ push_node(SerdReader* reader, SerdType type, const char* str, size_t n_bytes)
 SerdNode*
 deref(SerdReader* reader, const Ref ref)
 {
-	if (ref) {
-		SerdNode* node = (SerdNode*)(reader->stack.buf + ref);
-		node->buf = (char*)node + sizeof(SerdNode);
-		return node;
-	}
-	return NULL;
+	return ref ? (SerdNode*)(reader->stack.buf + ref) : NULL;
 }
 
 Ref
@@ -136,8 +132,8 @@ bool
 emit_statement(SerdReader* reader, ReadContext ctx, Ref o, Ref d, Ref l)
 {
 	SerdNode* graph = deref(reader, ctx.graph);
-	if (!graph && reader->default_graph.buf) {
-		graph = &reader->default_graph;
+	if (!graph && reader->default_graph) {
+		graph = reader->default_graph;
 	}
 	bool ret = !reader->statement_sink ||
 		!reader->statement_sink(
@@ -179,7 +175,7 @@ serd_reader_new(SerdSyntax        syntax,
 	me->prefix_sink      = prefix_sink;
 	me->statement_sink   = statement_sink;
 	me->end_sink         = end_sink;
-	me->default_graph    = SERD_NODE_NULL;
+	me->default_graph    = NULL;
 	me->stack            = serd_stack_new(SERD_PAGE_SIZE);
 	me->syntax           = syntax;
 	me->next_id          = 1;
@@ -213,7 +209,7 @@ serd_reader_free(SerdReader* reader)
 	pop_node(reader, reader->rdf_nil);
 	pop_node(reader, reader->rdf_rest);
 	pop_node(reader, reader->rdf_first);
-	serd_node_free(&reader->default_graph);
+	serd_node_free(reader->default_graph);
 
 #ifdef SERD_STACK_CHECK
 	free(reader->allocs);
@@ -250,7 +246,7 @@ void
 serd_reader_set_default_graph(SerdReader*     reader,
                               const SerdNode* graph)
 {
-	serd_node_free(&reader->default_graph);
+	serd_node_free(reader->default_graph);
 	reader->default_graph = serd_node_copy(graph);
 }
 
diff --git a/src/serd_internal.h b/src/serd_internal.h
index dae90535..86b03124 100644
--- a/src/serd_internal.h
+++ b/src/serd_internal.h
@@ -51,7 +51,15 @@
 
 static const uint8_t replacement_char[] = { 0xEF, 0xBF, 0xBD };
 
-char* serd_node_buffer(SerdNode* node);
+struct SerdNodeImpl {
+	size_t        n_bytes;  /**< Size in bytes (not including null) */
+	SerdNodeFlags flags;    /**< Node flags (e.g. string properties) */
+	SerdType      type;     /**< Node type */
+};
+
+SerdNode* serd_node_malloc(size_t n_bytes, SerdNodeFlags flags, SerdType type);
+void      serd_node_set(SerdNode** dst, const SerdNode* src);
+char*     serd_node_buffer(SerdNode* node);
 
 /* File and Buffer Utilities */
 
@@ -586,7 +594,7 @@ struct SerdReaderImpl {
 	Ref               rdf_first;
 	Ref               rdf_rest;
 	Ref               rdf_nil;
-	SerdNode          default_graph;
+	SerdNode*         default_graph;
 	SerdByteSource    source;
 	SerdStack         stack;
 	SerdSyntax        syntax;
diff --git a/src/serdi.c b/src/serdi.c
index 23abc5a0..ac11a7da 100644
--- a/src/serdi.c
+++ b/src/serdi.c
@@ -235,8 +235,8 @@ main(int argc, char** argv)
 			: SERD_NQUADS);
 	}
 
-	SerdURI  base_uri = SERD_URI_NULL;
-	SerdNode base     = SERD_NODE_NULL;
+	SerdURI   base_uri = SERD_URI_NULL;
+	SerdNode* base     = NULL;
 	if (a < argc) {  // Base URI given on command line
 		base = serd_node_new_uri_from_string(
 			(const char*)argv[a], NULL, &base_uri);
@@ -245,7 +245,7 @@ main(int argc, char** argv)
 	}
 
 	FILE*    out_fd = stdout;
-	SerdEnv* env    = serd_env_new(&base);
+	SerdEnv* env    = serd_env_new(base);
 
 	int output_style = 0;
 	if (output_syntax == SERD_NTRIPLES || ascii) {
@@ -284,10 +284,11 @@ main(int argc, char** argv)
 		serd_writer_set_error_sink(writer, quiet_error_sink, NULL);
 	}
 
-	SerdNode root = serd_node_from_string(SERD_URI, root_uri);
-	serd_writer_set_root_uri(writer, &root);
+	SerdNode* root = serd_node_new_string(SERD_URI, root_uri);
+	serd_writer_set_root_uri(writer, root);
 	serd_writer_chop_blank_prefix(writer, chop_prefix);
 	serd_reader_add_blank_prefix(reader, add_prefix);
+	serd_node_free(root);
 
 	SerdStatus status = SERD_SUCCESS;
 	if (!from_file) {
@@ -306,7 +307,7 @@ main(int argc, char** argv)
 	serd_writer_finish(writer);
 	serd_writer_free(writer);
 	serd_env_free(env);
-	serd_node_free(&base);
+	serd_node_free(base);
 
 	if (from_file) {
 		fclose(in_fd);
diff --git a/src/writer.c b/src/writer.c
index 230231eb..c570c7ba 100644
--- a/src/writer.c
+++ b/src/writer.c
@@ -27,16 +27,12 @@
 #include <string.h>
 
 typedef struct {
-	SerdNode graph;
-	SerdNode subject;
-	SerdNode predicate;
+	SerdNode* graph;
+	SerdNode* subject;
+	SerdNode* predicate;
 } WriteContext;
 
-static const WriteContext WRITE_CONTEXT_NULL = {
-	{ 0, 0, 0, SERD_NOTHING },
-	{ 0, 0, 0, SERD_NOTHING },
-	{ 0, 0, 0, SERD_NOTHING }
-};
+static const WriteContext WRITE_CONTEXT_NULL = { NULL, NULL, NULL };
 
 typedef enum {
 	SEP_NONE,
@@ -87,7 +83,7 @@ struct SerdWriterImpl {
 	SerdSyntax    syntax;
 	SerdStyle     style;
 	SerdEnv*      env;
-	SerdNode      root_node;
+	SerdNode*     root_node;
 	SerdURI       root_uri;
 	SerdURI       base_uri;
 	SerdStack     anon_stack;
@@ -95,7 +91,7 @@ struct SerdWriterImpl {
 	SerdErrorSink error_sink;
 	void*         error_handle;
 	WriteContext  context;
-	SerdNode      list_subj;
+	SerdNode*     list_subj;
 	unsigned      list_depth;
 	unsigned      indent;
 	char*         bprefix;
@@ -147,18 +143,19 @@ anon_stack_top(SerdWriter* writer)
 	                       + writer->anon_stack.size - sizeof(WriteContext));
 }
 
-static void
-copy_node(SerdNode* dst, const SerdNode* src)
-{
-	if (src) {
-		dst->buf = (char*)realloc((char*)dst->buf, src->n_bytes + 1);
-		dst->n_bytes = src->n_bytes;
-		dst->flags   = src->flags;
-		dst->type    = src->type;
-		memcpy((char*)dst->buf, src->buf, src->n_bytes + 1);
-	} else {
-		dst->type = SERD_NOTHING;
+static inline SerdNode*
+ctx(SerdWriter* writer, const Field field)
+{
+	SerdNode* node = NULL;
+	if (field == FIELD_SUBJECT) {
+		node = writer->context.subject;
+	} else if (field == FIELD_PREDICATE) {
+		node = writer->context.predicate;
+	} else if (field == FIELD_GRAPH) {
+		node = writer->context.graph;
 	}
+
+	return node && node->type ? node : NULL;
 }
 
 static inline size_t
@@ -402,22 +399,26 @@ write_sep(SerdWriter* writer, const Sep sep)
 static SerdStatus
 reset_context(SerdWriter* writer, bool graph)
 {
-	if (graph) {
-		writer->context.graph.type = SERD_NOTHING;
+	if (graph && writer->context.graph) {
+		memset(writer->context.graph, 0, sizeof(SerdNode));
 	}
-	writer->context.subject.type   = SERD_NOTHING;
-	writer->context.predicate.type = SERD_NOTHING;
-	writer->empty                  = false;
+	if (writer->context.subject) {
+		memset(writer->context.subject, 0, sizeof(SerdNode));
+	}
+	if (writer->context.predicate) {
+		memset(writer->context.predicate, 0, sizeof(SerdNode));
+	}
+	writer->empty = false;
 	return SERD_SUCCESS;
 }
 
 static SerdStatus
 free_context(SerdWriter* writer)
 {
-	serd_node_free(&writer->context.graph);
-	serd_node_free(&writer->context.subject);
-	serd_node_free(&writer->context.predicate);
-	return reset_context(writer, true);
+	serd_node_free(writer->context.graph);
+	serd_node_free(writer->context.subject);
+	serd_node_free(writer->context.predicate);
+	return SERD_SUCCESS;
 }
 
 static bool
@@ -495,8 +496,8 @@ write_uri_node(SerdWriter* const        writer,
                const Field              field,
                const SerdStatementFlags flags)
 {
-	SerdNode       prefix;
-	SerdStringView suffix;
+	const SerdNode* prefix = NULL;
+	SerdStringView  suffix = {NULL, 0};
 
 	if (is_inline_start(writer, field, flags)) {
 		++writer->indent;
@@ -514,7 +515,7 @@ write_uri_node(SerdWriter* const        writer,
 	} 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_from_node(writer, &prefix);
+		write_uri_from_node(writer, prefix);
 		sink(":", 1, writer);
 		write_uri(writer, suffix.buf, suffix.len);
 		return true;
@@ -601,7 +602,7 @@ write_blank(SerdWriter* const        writer,
 			return write_sep(writer, SEP_ANON_BEGIN);
 		} else if (field == FIELD_SUBJECT && (flags & SERD_LIST_S_BEGIN)) {
 			assert(writer->list_depth == 0);
-			copy_node(&writer->list_subj, node);
+			serd_node_set(&writer->list_subj, node);
 			++writer->list_depth;
 			++writer->indent;
 			return write_sep(writer, SEP_LIST_BEGIN);
@@ -666,7 +667,7 @@ write_pred(SerdWriter* writer, SerdStatementFlags flags, const SerdNode* pred)
 {
 	write_node(writer, pred, NULL, NULL, FIELD_PREDICATE, flags);
 	write_sep(writer, SEP_P_O);
-	copy_node(&writer->context.predicate, pred);
+	serd_node_set(&writer->context.predicate, pred);
 }
 
 static bool
@@ -698,9 +699,8 @@ serd_writer_write_statement(SerdWriter*        writer,
                             const SerdNode*    datatype,
                             const SerdNode*    lang)
 {
-	if (!subject || !predicate || !object
-	    || !subject->buf || !predicate->buf || !object->buf
-	    || !is_resource(subject) || !is_resource(predicate)) {
+	if (!subject || !predicate || !object ||
+	    !is_resource(subject) || !is_resource(predicate)) {
 		return SERD_ERR_BAD_ARG;
 	}
 
@@ -727,13 +727,13 @@ serd_writer_write_statement(SerdWriter*        writer,
 		break;
 	}
 
-	if ((graph && !serd_node_equals(graph, &writer->context.graph)) ||
-	    (!graph && writer->context.graph.type)) {
+	if ((graph && !serd_node_equals(graph, writer->context.graph)) ||
+	    (!graph && ctx(writer, FIELD_GRAPH))) {
 		writer->indent = 0;
-		if (writer->context.subject.type) {
+		if (ctx(writer, FIELD_SUBJECT)) {
 			write_sep(writer, SEP_END_S);
 		}
-		if (writer->context.graph.type) {
+		if (ctx(writer, FIELD_GRAPH)) {
 			write_sep(writer, SEP_GRAPH_END);
 		}
 
@@ -742,23 +742,23 @@ serd_writer_write_statement(SerdWriter*        writer,
 			TRY(write_node(writer, graph, datatype, lang, FIELD_GRAPH, flags));
 			++writer->indent;
 			write_sep(writer, SEP_GRAPH_BEGIN);
-			copy_node(&writer->context.graph, graph);
+			serd_node_set(&writer->context.graph, graph);
 		}
 	}
 
 	if ((flags & SERD_LIST_CONT)) {
 		if (write_list_obj(writer, flags, predicate, object, datatype, lang)) {
 			// Reached end of list
-			if (--writer->list_depth == 0 && writer->list_subj.type) {
+			if (--writer->list_depth == 0 && writer->list_subj) {
 				reset_context(writer, false);
-				serd_node_free(&writer->context.subject);
+				serd_node_free(writer->context.subject);
 				writer->context.subject = writer->list_subj;
-				writer->list_subj       = SERD_NODE_NULL;
+				writer->list_subj = NULL;
 			}
 			return SERD_SUCCESS;
 		}
-	} else if (serd_node_equals(subject, &writer->context.subject)) {
-		if (serd_node_equals(predicate, &writer->context.predicate)) {
+	} else if (serd_node_equals(subject, writer->context.subject)) {
+		if (serd_node_equals(predicate, writer->context.predicate)) {
 			// Abbreviate S P
 			if (!(flags & SERD_ANON_O_BEGIN)) {
 				++writer->indent;
@@ -770,14 +770,14 @@ serd_writer_write_statement(SerdWriter*        writer,
 			}
 		} else {
 			// Abbreviate S
-			Sep sep = writer->context.predicate.type ? SEP_END_P : SEP_S_P;
+			Sep sep = ctx(writer, FIELD_PREDICATE) ? SEP_END_P : SEP_S_P;
 			write_sep(writer, sep);
 			write_pred(writer, flags, predicate);
 			write_node(writer, object, datatype, lang, FIELD_OBJECT, flags);
 		}
 	} else {
 		// No abbreviation
-		if (writer->context.subject.type) {
+		if (ctx(writer, FIELD_SUBJECT)) {
 			assert(writer->indent > 0);
 			--writer->indent;
 			if (serd_stack_is_empty(&writer->anon_stack)) {
@@ -796,7 +796,7 @@ serd_writer_write_statement(SerdWriter*        writer,
 		}
 
 		reset_context(writer, false);
-		copy_node(&writer->context.subject, subject);
+		serd_node_set(&writer->context.subject, subject);
 
 		if (!(flags & SERD_LIST_S_BEGIN)) {
 			write_pred(writer, flags, predicate);
@@ -810,15 +810,15 @@ serd_writer_write_statement(SerdWriter*        writer,
 			&writer->anon_stack, sizeof(WriteContext));
 		*ctx = writer->context;
 		WriteContext new_context = {
-			serd_node_copy(graph), serd_node_copy(subject), SERD_NODE_NULL };
+			serd_node_copy(graph), serd_node_copy(subject), NULL };
 		if ((flags & SERD_ANON_S_BEGIN)) {
 			new_context.predicate = serd_node_copy(predicate);
 		}
 		writer->context = new_context;
 	} else {
-		copy_node(&writer->context.graph, graph);
-		copy_node(&writer->context.subject, subject);
-		copy_node(&writer->context.predicate, predicate);
+		serd_node_set(&writer->context.graph, graph);
+		serd_node_set(&writer->context.subject, subject);
+		serd_node_set(&writer->context.predicate, predicate);
 	}
 
 	return SERD_SUCCESS;
@@ -841,10 +841,10 @@ serd_writer_end_anon(SerdWriter*     writer,
 	free_context(writer);
 	writer->context = *anon_stack_top(writer);
 	serd_stack_pop(&writer->anon_stack, sizeof(WriteContext));
-	const bool is_subject = serd_node_equals(node, &writer->context.subject);
+	const bool is_subject = serd_node_equals(node, writer->context.subject);
 	if (is_subject) {
-		copy_node(&writer->context.subject, node);
-		writer->context.predicate.type = SERD_NOTHING;
+		serd_node_set(&writer->context.subject, node);
+		memset(writer->context.predicate, 0, sizeof(SerdNode));
 	}
 	return SERD_SUCCESS;
 }
@@ -852,15 +852,17 @@ serd_writer_end_anon(SerdWriter*     writer,
 SerdStatus
 serd_writer_finish(SerdWriter* writer)
 {
-	if (writer->context.subject.type) {
+	if (ctx(writer, FIELD_SUBJECT)) {
 		write_sep(writer, SEP_END_S);
 	}
-	if (writer->context.graph.type) {
+	if (ctx(writer, FIELD_GRAPH)) {
 		write_sep(writer, SEP_GRAPH_END);
 	}
 	serd_byte_sink_flush(&writer->byte_sink);
-	writer->indent = 0;
-	return free_context(writer);
+	free_context(writer);
+	writer->indent  = 0;
+	writer->context = WRITE_CONTEXT_NULL;
+	return SERD_SUCCESS;
 }
 
 SerdWriter*
@@ -876,12 +878,12 @@ serd_writer_new(SerdSyntax     syntax,
 	writer->syntax       = syntax;
 	writer->style        = style;
 	writer->env          = env;
-	writer->root_node    = SERD_NODE_NULL;
+	writer->root_node    = NULL;
 	writer->root_uri     = SERD_URI_NULL;
 	writer->base_uri     = base_uri ? *base_uri : SERD_URI_NULL;
 	writer->anon_stack   = serd_stack_new(4 * sizeof(WriteContext));
 	writer->context      = context;
-	writer->list_subj    = SERD_NODE_NULL;
+	writer->list_subj    = NULL;
 	writer->empty        = true;
 	writer->byte_sink    = serd_byte_sink_new(
 		ssink, stream, (style & SERD_STYLE_BULK) ? SERD_PAGE_SIZE : 1);
@@ -919,7 +921,7 @@ serd_writer_set_base_uri(SerdWriter*     writer,
 		serd_env_get_base_uri(writer->env, &writer->base_uri);
 
 		if (writer->syntax == SERD_TURTLE || writer->syntax == SERD_TRIG) {
-			if (writer->context.graph.type || writer->context.subject.type) {
+			if (ctx(writer, FIELD_GRAPH) || ctx(writer, FIELD_SUBJECT)) {
 				sink(" .\n\n", 4, writer);
 				reset_context(writer, true);
 			}
@@ -937,12 +939,13 @@ SerdStatus
 serd_writer_set_root_uri(SerdWriter*     writer,
                          const SerdNode* uri)
 {
-	serd_node_free(&writer->root_node);
-	if (uri && uri->buf) {
+	serd_node_free(writer->root_node);
+	if (uri) {
 		writer->root_node = serd_node_copy(uri);
-		serd_uri_parse(serd_node_get_string(uri), &writer->root_uri);
+		serd_uri_parse(serd_node_get_string(writer->root_node),
+		               &writer->root_uri);
 	} else {
-		writer->root_node = SERD_NODE_NULL;
+		writer->root_node = NULL;
 		writer->root_uri  = SERD_URI_NULL;
 	}
 	return SERD_SUCCESS;
@@ -955,7 +958,7 @@ serd_writer_set_prefix(SerdWriter*     writer,
 {
 	if (!serd_env_set_prefix(writer->env, name, uri)) {
 		if (writer->syntax == SERD_TURTLE || writer->syntax == SERD_TRIG) {
-			if (writer->context.graph.type || writer->context.subject.type) {
+			if (ctx(writer, FIELD_GRAPH) || ctx(writer, FIELD_SUBJECT)) {
 				sink(" .\n\n", 4, writer);
 				reset_context(writer, true);
 			}
@@ -978,7 +981,7 @@ serd_writer_free(SerdWriter* writer)
 	serd_stack_free(&writer->anon_stack);
 	free(writer->bprefix);
 	serd_byte_sink_free(&writer->byte_sink);
-	serd_node_free(&writer->root_node);
+	serd_node_free(writer->root_node);
 	free(writer);
 }
 
diff --git a/tests/serd_test.c b/tests/serd_test.c
index 5ab22846..e4cf992e 100644
--- a/tests/serd_test.c
+++ b/tests/serd_test.c
@@ -97,16 +97,17 @@ test_file_uri(const char* hostname,
 		expected_path = path;
 	}
 
-	SerdNode node         = serd_node_new_file_uri(path, hostname, 0, escape);
-	char*    out_hostname = NULL;
-	char*    out_path     = serd_file_uri_parse(node.buf, &out_hostname);
-	assert(!strcmp(node.buf, expected_uri));
+	SerdNode*   node     = serd_node_new_file_uri(path, hostname, 0, escape);
+	const char* node_str = serd_node_get_string(node);
+	char*       out_hostname = NULL;
+	char*       out_path     = serd_file_uri_parse(node_str, &out_hostname);
+	assert(!strcmp(node_str, expected_uri));
 	assert((hostname && out_hostname) || (!hostname && !out_hostname));
 	assert(!strcmp(out_path, expected_path));
 
 	serd_free(out_path);
 	serd_free(out_hostname);
-	serd_node_free(&node);
+	serd_node_free(node);
 }
 
 static void
@@ -216,14 +217,14 @@ test_double_to_node(void)
 	};
 
 	for (unsigned i = 0; i < sizeof(dbl_test_nums) / sizeof(double); ++i) {
-		SerdNode   node = serd_node_new_decimal(dbl_test_nums[i], 8);
-		const bool pass = (node.buf && dbl_test_strs[i])
-			? !strcmp(node.buf, dbl_test_strs[i])
-			: (node.buf == dbl_test_strs[i]);
+		SerdNode*   node     = serd_node_new_decimal(dbl_test_nums[i], 8);
+		const char* node_str = serd_node_get_string(node);
+		const bool  pass     = (node_str && dbl_test_strs[i])
+		                          ? !strcmp(node_str, dbl_test_strs[i])
+		                          : (node_str == dbl_test_strs[i]);
 		assert(pass);
-		const size_t len = node.buf ? strlen(node.buf) : 0;
-		assert(node.n_bytes == len);
-		serd_node_free(&node);
+		assert(serd_node_get_length(node) == (node_str ? strlen(node_str) : 0));
+		serd_node_free(node);
 	}
 }
 
@@ -239,36 +240,40 @@ test_integer_to_node(void)
 	};
 
 	for (unsigned i = 0; i < sizeof(int_test_nums) / sizeof(double); ++i) {
-		SerdNode node = serd_node_new_integer(int_test_nums[i]);
-		assert(!strcmp(node.buf, int_test_strs[i]));
-		assert(node.n_bytes == strlen(node.buf));
-		serd_node_free(&node);
+		SerdNode*   node     = serd_node_new_integer(int_test_nums[i]);
+		const char* node_str = serd_node_get_string(node);
+		assert(!strcmp(node_str, int_test_strs[i]));
+		assert(serd_node_get_length(node) == strlen(node_str));
+		serd_node_free(node);
 	}
 }
 
 static void
 test_blob_to_node(void)
 {
-	for (size_t size = 0; size < 256; ++size) {
+	assert(!serd_node_new_blob(NULL, 0, true));
+	assert(!serd_node_new_blob("data", 0, true));
+
+	for (size_t size = 1; size < 256; ++size) {
 		uint8_t* data = size > 0 ? (uint8_t*)malloc(size) : NULL;
 		for (size_t i = 0; i < size; ++i) {
 			data[i] = (uint8_t)(rand() % 256);
 		}
 
-		SerdNode blob = serd_node_new_blob(data, size, size % 5);
-
-		assert(blob.n_bytes == strlen(blob.buf));
+		size_t      out_size = 0;
+		SerdNode*   blob     = serd_node_new_blob(data, size, size % 5);
+		const char* blob_str = serd_node_get_string(blob);
+		uint8_t*    out      = (uint8_t*)serd_base64_decode(
+			blob_str, serd_node_get_length(blob), &out_size);
 
-		size_t   out_size = 0;
-		uint8_t* out = (uint8_t*)serd_base64_decode(
-			blob.buf, blob.n_bytes, &out_size);
+		assert(serd_node_get_length(blob) == strlen(blob_str));
 		assert(out_size == size);
 
 		for (size_t i = 0; i < size; ++i) {
 			assert(out[i] == data[i]);
 		}
 
-		serd_node_free(&blob);
+		serd_node_free(blob);
 		serd_free(out);
 		free(data);
 	}
@@ -352,145 +357,161 @@ static void
 test_node_equals(void)
 {
 	const uint8_t replacement_char_str[] = { 0xEF, 0xBF, 0xBD, 0 };
-	SerdNode lhs = serd_node_from_string(SERD_LITERAL, (const char*)replacement_char_str);
-	SerdNode rhs = serd_node_from_string(SERD_LITERAL, "123");
-	assert(!serd_node_equals(&lhs, &rhs));
+	SerdNode* lhs = serd_node_new_string(SERD_LITERAL, (const char*)replacement_char_str);
+	SerdNode* rhs = serd_node_new_string(SERD_LITERAL, "123");
+	assert(!serd_node_equals(lhs, rhs));
+
+	SerdNode* qnode = serd_node_new_string(SERD_CURIE, "foo:bar");
+	assert(!serd_node_equals(lhs, qnode));
+	assert(serd_node_equals(lhs, lhs));
 
-	SerdNode qnode = serd_node_from_string(SERD_CURIE, "foo:bar");
-	assert(!serd_node_equals(&lhs, &qnode));
-	assert(serd_node_equals(&lhs, &lhs));
+	assert(!serd_node_copy(NULL));
 
-	SerdNode null_copy = serd_node_copy(&SERD_NODE_NULL);
-	assert(serd_node_equals(&SERD_NODE_NULL, &null_copy));
+	serd_node_free(qnode);
+	serd_node_free(lhs);
+	serd_node_free(rhs);
 }
 
 static void
 test_node_from_string(void)
 {
-	SerdNode node = serd_node_from_string(SERD_LITERAL, "hello\"");
-	assert(node.n_bytes == 6 && node.flags == SERD_HAS_QUOTE &&
-	       !strcmp(node.buf, "hello\""));
+	SerdNode* hello = serd_node_new_string(SERD_LITERAL, "hello\"");
+	assert(serd_node_get_length(hello) == 6 &&
+	       serd_node_get_flags(hello) == SERD_HAS_QUOTE &&
+	       !strcmp(serd_node_get_string(hello), "hello\""));
 
-	node = serd_node_from_string(SERD_URI, NULL);
-	assert(serd_node_equals(&node, &SERD_NODE_NULL));
+	assert(!serd_node_new_string(SERD_URI, NULL));
+	serd_node_free(hello);
 }
 
 static void
 test_node_from_substring(void)
 {
-	SerdNode empty = serd_node_from_substring(SERD_LITERAL, NULL, 32);
-	assert(!empty.buf && !empty.n_bytes && !empty.flags && !empty.type);
-
-	SerdNode a_b = serd_node_from_substring(SERD_LITERAL, "a\"bc", 3);
-	assert(a_b.n_bytes == 3 && a_b.flags == SERD_HAS_QUOTE &&
-	       !strncmp(a_b.buf, "a\"b", 3));
-
-	a_b = serd_node_from_substring(SERD_LITERAL, "a\"bc", 10);
-	assert(a_b.n_bytes == 4 && a_b.flags == SERD_HAS_QUOTE &&
-	       !strncmp(a_b.buf, "a\"bc", 4));
+	assert(!serd_node_new_substring(SERD_LITERAL, NULL, 32));
+
+	SerdNode* a_b = serd_node_new_substring(SERD_LITERAL, "a\"bc", 3);
+	assert(serd_node_get_length(a_b) == 3 &&
+	       serd_node_get_flags(a_b) == SERD_HAS_QUOTE &&
+	       !strncmp(serd_node_get_string(a_b), "a\"b", 3));
+
+	serd_node_free(a_b);
+	a_b = serd_node_new_substring(SERD_LITERAL, "a\"bc", 10);
+	assert(serd_node_get_length(a_b) == 4 &&
+	       serd_node_get_flags(a_b) == SERD_HAS_QUOTE &&
+	       !strncmp(serd_node_get_string(a_b), "a\"bc", 4));
+	serd_node_free(a_b);
 }
 
 static void
 test_uri_from_string(void)
 {
-	SerdNode nonsense = serd_node_new_uri_from_string(NULL, NULL, NULL);
-	assert(nonsense.type == SERD_NOTHING);
-
-	SerdURI base_uri;
-	SerdNode base = serd_node_new_uri_from_string("http://example.org/",
-	                                              NULL, &base_uri);
-	SerdNode nil = serd_node_new_uri_from_string(NULL, &base_uri, NULL);
-	SerdNode nil2 = serd_node_new_uri_from_string("", &base_uri, NULL);
-	assert(nil.type == SERD_URI);
-	assert(!strcmp(nil.buf, base.buf));
-	assert(nil2.type == SERD_URI);
-	assert(!strcmp(nil2.buf, base.buf));
-	serd_node_free(&nil);
-	serd_node_free(&nil2);
-
-	serd_node_free(&base);
+	assert(!serd_node_new_uri_from_string(NULL, NULL, NULL));
+
+	SerdURI   base_uri;
+	SerdNode* base = serd_node_new_uri_from_string("http://example.org/",
+	                                               NULL, &base_uri);
+	SerdNode* nil  = serd_node_new_uri_from_string(NULL, &base_uri, NULL);
+	SerdNode* nil2 = serd_node_new_uri_from_string("", &base_uri, NULL);
+	assert(serd_node_get_type(nil) == SERD_URI);
+	assert(!strcmp(serd_node_get_string(nil), serd_node_get_string(base)));
+	assert(serd_node_get_type(nil2) == SERD_URI);
+	assert(!strcmp(serd_node_get_string(nil2), serd_node_get_string(base)));
+	serd_node_free(nil);
+	serd_node_free(nil2);
+	serd_node_free(base);
 }
 
 static void
 test_relative_uri(void)
 {
-	SerdURI  base_uri;
-	SerdNode base = serd_node_new_uri_from_string("http://example.org/",
-	                                              NULL, &base_uri);
-
-	SerdNode abs = serd_node_from_string(SERD_URI, "http://example.org/foo/bar");
-	SerdURI  abs_uri;
-	serd_uri_parse(abs.buf, &abs_uri);
-
-	SerdURI  rel_uri;
-	SerdNode rel = serd_node_new_relative_uri(&abs_uri, &base_uri, NULL, &rel_uri);
-	assert(!strcmp(rel.buf, "/foo/bar"));
-
-	SerdNode up = serd_node_new_relative_uri(&base_uri, &abs_uri, NULL, NULL);
-	assert(!strcmp(up.buf, "../"));
-
-	SerdNode noup = serd_node_new_relative_uri(&base_uri, &abs_uri, &abs_uri, NULL);
-	assert(!strcmp(noup.buf, "http://example.org/"));
-
-	SerdNode x = serd_node_from_string(SERD_URI, "http://example.org/foo/x");
-	SerdURI  x_uri;
-	serd_uri_parse(x.buf, &x_uri);
-
-	SerdNode x_rel = serd_node_new_relative_uri(&x_uri, &abs_uri, &abs_uri, NULL);
-	assert(!strcmp(x_rel.buf, "x"));
-
-	serd_node_free(&x_rel);
-	serd_node_free(&noup);
-	serd_node_free(&up);
-	serd_node_free(&rel);
-	serd_node_free(&base);
+	SerdURI   base_uri;
+	SerdNode* base = serd_node_new_uri_from_string("http://example.org/",
+	                                               NULL, &base_uri);
+
+	SerdNode* abs = serd_node_new_string(SERD_URI, "http://example.org/foo/bar");
+	SerdURI   abs_uri;
+	serd_uri_parse(serd_node_get_string(abs), &abs_uri);
+
+	SerdURI   rel_uri;
+	SerdNode* rel = serd_node_new_relative_uri(&abs_uri, &base_uri, NULL, &rel_uri);
+	assert(!strcmp(serd_node_get_string(rel), "/foo/bar"));
+
+	SerdNode* up = serd_node_new_relative_uri(&base_uri, &abs_uri, NULL, NULL);
+	assert(!strcmp(serd_node_get_string(up), "../"));
+
+	SerdNode* noup = serd_node_new_relative_uri(&base_uri, &abs_uri, &abs_uri, NULL);
+	assert(!strcmp(serd_node_get_string(noup), "http://example.org/"));
+
+	SerdNode* x = serd_node_new_string(SERD_URI, "http://example.org/foo/x");
+	SerdURI   x_uri;
+	serd_uri_parse(serd_node_get_string(x), &x_uri);
+
+	SerdNode* x_rel =
+		serd_node_new_relative_uri(&x_uri, &abs_uri, &abs_uri, NULL);
+	assert(!strcmp(serd_node_get_string(x_rel), "x"));
+
+	serd_node_free(x_rel);
+	serd_node_free(x);
+	serd_node_free(noup);
+	serd_node_free(up);
+	serd_node_free(abs);
+	serd_node_free(rel);
+	serd_node_free(base);
 }
 
 static void
 test_env(void)
 {
-	SerdNode u   = serd_node_from_string(SERD_URI, "http://example.org/foo");
-	SerdNode b   = serd_node_from_string(SERD_CURIE, "invalid");
-	SerdNode c   = serd_node_from_string(SERD_CURIE, "eg.2:b");
-	SerdEnv* env = serd_env_new(NULL);
+	SerdNode* u   = serd_node_new_string(SERD_URI, "http://example.org/foo");
+	SerdNode* b   = serd_node_new_string(SERD_CURIE, "invalid");
+	SerdNode* c   = serd_node_new_string(SERD_CURIE, "eg.2:b");
+	SerdNode* s   = serd_node_new_string(SERD_LITERAL, "hello");
+	SerdEnv*  env = serd_env_new(NULL);
 	serd_env_set_prefix_from_strings(env, "eg.2", "http://example.org/");
 
-	assert(serd_env_set_base_uri(env, NULL));
-	assert(serd_env_set_base_uri(env, &SERD_NODE_NULL));
-	assert(serd_node_equals(serd_env_get_base_uri(env, NULL), &SERD_NODE_NULL));
-
 	SerdStringView prefix;
 	SerdStringView suffix;
-	assert(serd_env_expand(env, &b, &prefix, &suffix));
+	assert(serd_env_expand(env, b, &prefix, &suffix));
 
-	SerdNode xnode = serd_env_expand_node(env, &SERD_NODE_NULL);
-	assert(serd_node_equals(&xnode, &SERD_NODE_NULL));
+	assert(!serd_env_expand_node(env, b));
+	assert(!serd_env_expand_node(env, s));
 
-	SerdNode xu = serd_env_expand_node(env, &u);
-	assert(!strcmp(xu.buf, "http://example.org/foo"));
-	serd_node_free(&xu);
+	assert(serd_env_set_base_uri(NULL, u));
+	assert(serd_env_set_base_uri(env, NULL));
+
+	SerdNode* xu = serd_env_expand_node(env, u);
+	assert(!strcmp(serd_node_get_string(xu), "http://example.org/foo"));
+	serd_node_free(xu);
 
-	SerdNode badpre = serd_node_from_string(SERD_CURIE, "hm:what");
-	SerdNode xbadpre = serd_env_expand_node(env, &badpre);
-	assert(serd_node_equals(&xbadpre, &SERD_NODE_NULL));
+	SerdNode* badpre  = serd_node_new_string(SERD_CURIE, "hm:what");
+	SerdNode* xbadpre = serd_env_expand_node(env, badpre);
+	assert(!xbadpre);
 
-	SerdNode xc = serd_env_expand_node(env, &c);
-	assert(!strcmp(xc.buf, "http://example.org/b"));
-	serd_node_free(&xc);
+	SerdNode* xc = serd_env_expand_node(env, c);
+	assert(!strcmp(serd_node_get_string(xc), "http://example.org/b"));
+	serd_node_free(xc);
 
-	assert(serd_env_set_prefix(env, &SERD_NODE_NULL, &SERD_NODE_NULL));
+	assert(serd_env_set_prefix(env, NULL, NULL));
 
-	const SerdNode lit = serd_node_from_string(SERD_LITERAL, "hello");
-	assert(serd_env_set_prefix(env, &b, &lit));
+	SerdNode* lit = serd_node_new_string(SERD_LITERAL, "hello");
+	assert(serd_env_set_prefix(env, b, lit));
 
 	int n_prefixes = 0;
 	serd_env_set_prefix_from_strings(env, "eg.2", "http://example.org/");
 	serd_env_foreach(env, count_prefixes, &n_prefixes);
 	assert(n_prefixes == 1);
 
-	SerdNode shorter_uri = serd_node_from_string(SERD_URI, "urn:foo");
-	SerdNode prefix_name;
-	assert(!serd_env_qualify(env, &shorter_uri, &prefix_name, &suffix));
+	SerdNode*       shorter_uri = serd_node_new_string(SERD_URI, "urn:foo");
+	const SerdNode* prefix_name = NULL;
+	assert(!serd_env_qualify(env, shorter_uri, &prefix_name, &suffix));
+
+	serd_node_free(shorter_uri);
+	serd_node_free(lit);
+	serd_node_free(badpre);
+	serd_node_free(s);
+	serd_node_free(c);
+	serd_node_free(b);
+	serd_node_free(u);
 
 	serd_env_free(env);
 }
@@ -509,28 +530,28 @@ test_writer(const char* const path)
 	serd_writer_chop_blank_prefix(writer, "tmp");
 	serd_writer_chop_blank_prefix(writer, NULL);
 
-	const SerdNode lit = serd_node_from_string(SERD_LITERAL, "hello");
+	SerdNode* lit = serd_node_new_string(SERD_LITERAL, "hello");
 
-	assert(serd_writer_set_base_uri(writer, &lit));
-	assert(serd_writer_set_prefix(writer, &lit, &lit));
+	assert(serd_writer_set_base_uri(writer, lit));
+	assert(serd_writer_set_prefix(writer, lit, lit));
 	assert(serd_writer_end_anon(writer, NULL));
 	assert(serd_writer_get_env(writer) == env);
 
 	uint8_t buf[] = { 0xEF, 0xBF, 0xBD, 0 };
-	SerdNode s = serd_node_from_string(SERD_URI, "");
-	SerdNode p = serd_node_from_string(SERD_URI, "http://example.org/pred");
-	SerdNode o = serd_node_from_string(SERD_LITERAL, (char*)buf);
+	SerdNode* s = serd_node_new_string(SERD_URI, "");
+	SerdNode* p = serd_node_new_string(SERD_URI, "http://example.org/pred");
+	SerdNode* o = serd_node_new_string(SERD_LITERAL, (char*)buf);
 
 	// Write 3 invalid statements (should write nothing)
-	const SerdNode* junk[][5] = { { &s, &p, NULL, NULL, NULL },
-	                              { &s, NULL, &o, NULL, NULL },
-	                              { NULL, &p, &o, NULL, NULL },
-	                              { &s, &p, &SERD_NODE_NULL, NULL, NULL },
-	                              { &s, &SERD_NODE_NULL, &o, NULL, NULL },
-	                              { &SERD_NODE_NULL, &p, &o, NULL, NULL },
-	                              { &s, &o, &o, NULL, NULL },
-	                              { &o, &p, &o, NULL, NULL },
-	                              { &s, &p, &SERD_NODE_NULL, NULL, NULL },
+	const SerdNode* junk[][5] = { { s,    p,    NULL, NULL, NULL },
+	                              { s,    NULL, o,    NULL, NULL },
+	                              { NULL, p,    o,    NULL, NULL },
+	                              { s,    p,    NULL, NULL, NULL },
+	                              { s,    NULL, o,    NULL, NULL },
+	                              { NULL, p,    o,    NULL, NULL },
+	                              { s,    o,    o,    NULL, NULL },
+	                              { o,    p,    o,    NULL, NULL },
+	                              { s,    p,    NULL, NULL, NULL },
 	                              { NULL, NULL, NULL, NULL, NULL } };
 	for (unsigned i = 0; i < sizeof(junk) / (sizeof(SerdNode*) * 5); ++i) {
 		assert(serd_writer_write_statement(
@@ -538,18 +559,18 @@ test_writer(const char* const path)
 			       junk[i][0], junk[i][1], junk[i][2], junk[i][3], junk[i][4]));
 	}
 
-	const SerdNode t = serd_node_from_string(SERD_URI, "urn:Type");
-	const SerdNode l = serd_node_from_string(SERD_LITERAL, "en");
-	const SerdNode* good[][5] = { { &s, &p, &o, NULL, NULL },
-	                              { &s, &p, &o, &SERD_NODE_NULL, &SERD_NODE_NULL },
-	                              { &s, &p, &o, &t, NULL },
-	                              { &s, &p, &o, NULL, &l },
-	                              { &s, &p, &o, &t, &l },
-	                              { &s, &p, &o, &t, &SERD_NODE_NULL },
-	                              { &s, &p, &o, &SERD_NODE_NULL, &l },
-	                              { &s, &p, &o, NULL, &SERD_NODE_NULL },
-	                              { &s, &p, &o, &SERD_NODE_NULL, NULL },
-	                              { &s, &p, &o, &SERD_NODE_NULL, NULL } };
+	SerdNode* t = serd_node_new_string(SERD_URI, "urn:Type");
+	SerdNode* l = serd_node_new_string(SERD_LITERAL, "en");
+	const SerdNode* good[][5] = { { s, p, o, NULL, NULL },
+	                              { s, p, o, NULL, NULL },
+	                              { s, p, o, t,    NULL },
+	                              { s, p, o, NULL, l },
+	                              { s, p, o, t,    l },
+	                              { s, p, o, t,    NULL },
+	                              { s, p, o, NULL, l },
+	                              { s, p, o, NULL, NULL },
+	                              { s, p, o, NULL, NULL },
+	                              { s, p, o, NULL, NULL } };
 	for (unsigned i = 0; i < sizeof(good) / (sizeof(SerdNode*) * 5); ++i) {
 		assert(!serd_writer_write_statement(
 			       writer, 0, NULL,
@@ -557,29 +578,39 @@ test_writer(const char* const path)
 	}
 
 	// Write statements with bad UTF-8 (should be replaced)
-	const uint8_t bad_str[] = { 0xFF, 0x90, 'h', 'i', 0 };
-	SerdNode      bad_lit   = serd_node_from_string(SERD_LITERAL, (const char*)bad_str);
-	SerdNode      bad_uri   = serd_node_from_string(SERD_URI, (const char*)bad_str);
-	assert(!serd_writer_write_statement(writer, 0, NULL,
-	                                    &s, &p, &bad_lit, NULL, NULL));
+	const char bad_str[] = { (char)0xFF, (char)0x90, 'h', 'i', 0 };
+	SerdNode*  bad_lit   = serd_node_new_string(SERD_LITERAL, bad_str);
+	SerdNode*  bad_uri   = serd_node_new_string(SERD_URI, bad_str);
+	assert(!serd_writer_write_statement(
+	        writer, 0, NULL, s, p, bad_lit, NULL, NULL));
 	assert(!serd_writer_write_statement(writer, 0, NULL,
-	                                    &s, &p, &bad_uri, NULL, NULL));
+	                                    s, p, bad_uri, NULL, NULL));
+	serd_node_free(bad_lit);
+	serd_node_free(bad_uri);
 
 	// Write 1 valid statement
-	o = serd_node_from_string(SERD_LITERAL, "hello");
+	serd_node_free(o);
+	o = serd_node_new_string(SERD_LITERAL, "hello");
 	assert(!serd_writer_write_statement(writer, 0, NULL,
-	                                    &s, &p, &o, NULL, NULL));
+	                                    s, p, o, NULL, NULL));
 
 	serd_writer_free(writer);
+	serd_node_free(lit);
+	serd_node_free(s);
+	serd_node_free(p);
+	serd_node_free(o);
+	serd_node_free(t);
+	serd_node_free(l);
 
 	// Test buffer sink
 	SerdBuffer buffer = { NULL, 0 };
 	writer = serd_writer_new(
 		SERD_TURTLE, (SerdStyle)0, env, NULL, serd_buffer_sink, &buffer);
 
-	o = serd_node_from_string(SERD_URI, "http://example.org/base");
-	assert(!serd_writer_set_base_uri(writer, &o));
+	o = serd_node_new_string(SERD_URI, "http://example.org/base");
+	assert(!serd_writer_set_base_uri(writer, o));
 
+	serd_node_free(o);
 	serd_writer_free(writer);
 	char* out = serd_buffer_sink_finish(&buffer);
 
@@ -599,10 +630,11 @@ test_reader(const char* path)
 	assert(reader);
 	assert(serd_reader_get_handle(reader) == rt);
 
-	SerdNode g = serd_node_from_string(SERD_URI, "http://example.org/");
-	serd_reader_set_default_graph(reader, &g);
+	SerdNode* g = serd_node_new_string(SERD_URI, "http://example.org/");
+	serd_reader_set_default_graph(reader, g);
 	serd_reader_add_blank_prefix(reader, "tmp");
 	serd_reader_add_blank_prefix(reader, NULL);
+	serd_node_free(g);
 
 	assert(serd_reader_read_file(reader, "http://notafile"));
 	assert(serd_reader_read_file(reader, "file:///better/not/exist"));
@@ -611,8 +643,8 @@ test_reader(const char* path)
 	const SerdStatus st = serd_reader_read_file(reader, path);
 	assert(!st);
 	assert(rt->n_statements == 13);
-	assert(rt->graph && rt->graph->buf &&
-	       !strcmp(rt->graph->buf, "http://example.org/"));
+	assert(rt->graph && serd_node_get_string(rt->graph) &&
+	       !strcmp(serd_node_get_string(rt->graph), "http://example.org/"));
 
 	assert(serd_reader_read_string(reader, "This isn't Turtle at all."));