Use char* for strings in public API

The constant casting just makes user code a mess, for no benefit.

14 files changed, 275 insertions, 277 deletions

diff --git a/NEWS b/NEWS
index 446387d6..2e94537f 100644
--- a/NEWS
+++ b/NEWS
@@ -3,6 +3,7 @@ serd (1.0.0) unstable;
   * Use SerdBuffer for mutable buffers instead of abusing SerdChunk
   * Add serd_node_new_relative_uri()
   * Fix construction and comparison of URIs with UTF-8 characters
+  * Use char* for strings in public API
   * Remove useless character counting
   * Report I/O errors with message and return appropriate status code
   * Report missing statement separator errors
diff --git a/serd/serd.h b/serd/serd.h
index d289ee72..d3c6cdeb 100644
--- a/serd/serd.h
+++ b/serd/serd.h
@@ -215,7 +215,7 @@ typedef uint32_t SerdNodeFlags;
    A syntactic RDF node.
 */
 typedef struct {
-	const uint8_t* buf;      /**< Value string */
+	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 */
@@ -225,8 +225,8 @@ typedef struct {
    An unterminated string fragment.
 */
 typedef struct {
-	const uint8_t* buf;  /**< Start of chunk */
-	size_t         len;  /**< Length of chunk in bytes */
+	const char* buf;  /**< Start of chunk */
+	size_t      len;  /**< Length of chunk in bytes */
 } SerdChunk;
 
 /**
@@ -241,12 +241,12 @@ typedef struct {
    An error description.
 */
 typedef struct {
-	SerdStatus     status;    /**< Error code */
-	const uint8_t* filename;  /**< File where error was encountered, or NULL */
-	unsigned       line;      /**< Line where error was encountered, or 0 */
-	unsigned       col;       /**< Column where error was encountered */
-	const char*    fmt;       /**< Message format string (printf style) */
-	va_list*       args;      /**< Arguments for fmt */
+	SerdStatus  status;    /**< Error code */
+	const char* filename;  /**< File where error was encountered, or NULL */
+	unsigned    line;      /**< Line where error was encountered, or 0 */
+	unsigned    col;       /**< Column where error was encountered */
+	const char* fmt;       /**< Message format string (printf style) */
+	va_list*    args;      /**< Arguments for fmt */
 } SerdError;
 
 /**
@@ -290,7 +290,7 @@ typedef enum {
    Return a string describing a status code.
 */
 SERD_API
-const uint8_t*
+const char*
 serd_strerror(SerdStatus status);
 
 /**
@@ -301,7 +301,7 @@ serd_strerror(SerdStatus status);
 */
 SERD_API
 size_t
-serd_strlen(const uint8_t* str, SerdNodeFlags* flags);
+serd_strlen(const char* str, SerdNodeFlags* flags);
 
 /**
    Parse a string to a double.
@@ -326,7 +326,7 @@ serd_strtod(const char* str, char** endptr);
 */
 SERD_API
 void*
-serd_base64_decode(const uint8_t* str, size_t len, size_t* size);
+serd_base64_decode(const char* str, size_t len, size_t* size);
 
 /**
    @}
@@ -346,8 +346,8 @@ static const SerdURI SERD_URI_NULL = {
    a path, use serd_file_uri_parse().
 */
 SERD_API
-const uint8_t*
-serd_uri_to_path(const uint8_t* uri);
+const char*
+serd_uri_to_path(const char* uri);
 
 /**
    Get the unescaped path and hostname from a file URI.
@@ -358,22 +358,22 @@ serd_uri_to_path(const uint8_t* uri);
    The returned path and `*hostname` must be freed with free().
 */
 SERD_API
-uint8_t*
-serd_file_uri_parse(const uint8_t* uri, uint8_t** hostname);
+char*
+serd_file_uri_parse(const char* uri, char** hostname);
 
 /**
    Return true iff `utf8` starts with a valid URI scheme.
 */
 SERD_API
 bool
-serd_uri_string_has_scheme(const uint8_t* utf8);
+serd_uri_string_has_scheme(const char* utf8);
 
 /**
    Parse `utf8`, writing result to `out`.
 */
 SERD_API
 SerdStatus
-serd_uri_parse(const uint8_t* utf8, SerdURI* out);
+serd_uri_parse(const char* utf8, SerdURI* out);
 
 /**
    Set target `t` to reference `r` resolved against `base`.
@@ -452,7 +452,7 @@ static const SerdNode SERD_NODE_NULL = { NULL, 0, 0, SERD_NOTHING };
 */
 SERD_API
 SerdNode
-serd_node_from_string(SerdType type, const uint8_t* str);
+serd_node_from_string(SerdType type, const char* str);
 
 /**
    Make a (shallow) node from a prefix of `str`.
@@ -462,7 +462,7 @@ serd_node_from_string(SerdType type, const uint8_t* str);
 */
 SERD_API
 SerdNode
-serd_node_from_substring(SerdType type, const uint8_t* str, size_t len);
+serd_node_from_substring(SerdType type, const char* str, size_t len);
 
 /**
    Make a deep copy of `node`.
@@ -494,7 +494,7 @@ serd_node_new_uri_from_node(const SerdNode* uri_node,
 */
 SERD_API
 SerdNode
-serd_node_new_uri_from_string(const uint8_t* str,
+serd_node_new_uri_from_string(const char*    str,
                               const SerdURI* base,
                               SerdURI*       out);
 
@@ -510,10 +510,10 @@ serd_node_new_uri_from_string(const uint8_t* str,
 */
 SERD_API
 SerdNode
-serd_node_new_file_uri(const uint8_t* path,
-                       const uint8_t* hostname,
-                       SerdURI*       out,
-                       bool           escape);
+serd_node_new_file_uri(const char* path,
+                       const char* hostname,
+                       SerdURI*    out,
+                       bool        escape);
 
 /**
    Create a new node by serialising `uri` into a new string.
@@ -703,9 +703,9 @@ serd_env_set_prefix(SerdEnv*        env,
 */
 SERD_API
 SerdStatus
-serd_env_set_prefix_from_strings(SerdEnv*       env,
-                                 const uint8_t* name,
-                                 const uint8_t* uri);
+serd_env_set_prefix_from_strings(SerdEnv*    env,
+                                 const char* name,
+                                 const char* uri);
 
 /**
    Qualify `uri` into a CURIE if possible.
@@ -809,8 +809,8 @@ serd_reader_get_handle(const SerdReader* reader);
 */
 SERD_API
 void
-serd_reader_add_blank_prefix(SerdReader*    reader,
-                             const uint8_t* prefix);
+serd_reader_add_blank_prefix(SerdReader* reader,
+                             const char* prefix);
 
 /**
    Set the URI of the default graph.
@@ -829,8 +829,8 @@ serd_reader_set_default_graph(SerdReader*     reader,
 */
 SERD_API
 SerdStatus
-serd_reader_read_file(SerdReader*    reader,
-                      const uint8_t* uri);
+serd_reader_read_file(SerdReader* reader,
+                      const char* uri);
 
 /**
    Start an incremental read from a file handle.
@@ -842,10 +842,10 @@ serd_reader_read_file(SerdReader*    reader,
 */
 SERD_API
 SerdStatus
-serd_reader_start_stream(SerdReader*    reader,
-                         FILE*          file,
-                         const uint8_t* name,
-                         bool           bulk);
+serd_reader_start_stream(SerdReader* reader,
+                         FILE*       file,
+                         const char* name,
+                         bool        bulk);
 
 /**
    Start an incremental read from a user-specified source.
@@ -859,7 +859,7 @@ serd_reader_start_source_stream(SerdReader*         reader,
                                 SerdSource          read_func,
                                 SerdStreamErrorFunc error_func,
                                 void*               stream,
-                                const uint8_t*      name,
+                                const char*         name,
                                 size_t              page_size);
 
 /**
@@ -886,9 +886,9 @@ serd_reader_end_stream(SerdReader* reader);
 */
 SERD_API
 SerdStatus
-serd_reader_read_file_handle(SerdReader*    reader,
-                             FILE*          file,
-                             const uint8_t* name);
+serd_reader_read_file_handle(SerdReader* reader,
+                             FILE*       file,
+                             const char* name);
 
 /**
    Read a user-specified byte source.
@@ -899,7 +899,7 @@ serd_reader_read_source(SerdReader*         reader,
                         SerdSource          source,
                         SerdStreamErrorFunc error,
                         void*               stream,
-                        const uint8_t*      name,
+                        const char*         name,
                         size_t              page_size);
 
 /**
@@ -907,7 +907,7 @@ serd_reader_read_source(SerdReader*         reader,
 */
 SERD_API
 SerdStatus
-serd_reader_read_string(SerdReader* reader, const uint8_t* utf8);
+serd_reader_read_string(SerdReader* reader, const char* utf8);
 
 /**
    Free `reader`.
@@ -977,7 +977,7 @@ serd_buffer_sink(const void* buf, size_t len, void* stream);
    terminated (by this function) and owned by the caller.
 */
 SERD_API
-uint8_t*
+char*
 serd_buffer_sink_finish(SerdBuffer* stream);
 
 /**
@@ -997,8 +997,8 @@ serd_writer_set_error_sink(SerdWriter*   writer,
 */
 SERD_API
 void
-serd_writer_chop_blank_prefix(SerdWriter*    writer,
-                              const uint8_t* prefix);
+serd_writer_chop_blank_prefix(SerdWriter* writer,
+                              const char* prefix);
 
 /**
    Set the current output base URI (and emit directive if applicable).
diff --git a/src/byte_source.c b/src/byte_source.c
index e2bcf196..74ce14a4 100644
--- a/src/byte_source.c
+++ b/src/byte_source.c
@@ -38,7 +38,7 @@ serd_byte_source_open_source(SerdByteSource*     source,
                              SerdSource          read_func,
                              SerdStreamErrorFunc error_func,
                              void*               stream,
-                             const uint8_t*      name,
+                             const char*         name,
                              size_t              page_size)
 {
 	const Cursor cur = { name, 1, 1 };
@@ -52,7 +52,7 @@ serd_byte_source_open_source(SerdByteSource*     source,
 	source->read_func   = read_func;
 
 	if (page_size > 1) {
-		source->file_buf = (uint8_t*)serd_bufalloc(page_size);
+		source->file_buf = (char*)serd_bufalloc(page_size);
 		source->read_buf = source->file_buf;
 		memset(source->file_buf, '\0', page_size);
 	} else {
@@ -78,9 +78,9 @@ serd_byte_source_prepare(SerdByteSource* source)
 }
 
 SerdStatus
-serd_byte_source_open_string(SerdByteSource* source, const uint8_t* utf8)
+serd_byte_source_open_string(SerdByteSource* source, const char* utf8)
 {
-	const Cursor cur = { (const uint8_t*)"(string)", 1, 1 };
+	const Cursor cur = { "(string)", 1, 1 };
 
 	memset(source, '\0', sizeof(*source));
 	source->cur      = cur;
diff --git a/src/env.c b/src/env.c
index cf1c3538..7831daf7 100644
--- a/src/env.c
+++ b/src/env.c
@@ -92,7 +92,7 @@ serd_env_set_base_uri(SerdEnv*        env,
 
 static inline SerdPrefix*
 serd_env_find(const SerdEnv* env,
-              const uint8_t* name,
+              const char*    name,
               size_t         name_len)
 {
 	for (size_t i = 0; i < env->n_prefixes; ++i) {
@@ -150,9 +150,9 @@ serd_env_set_prefix(SerdEnv*        env,
 
 SERD_API
 SerdStatus
-serd_env_set_prefix_from_strings(SerdEnv*       env,
-                                 const uint8_t* name,
-                                 const uint8_t* uri)
+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);
@@ -161,7 +161,7 @@ serd_env_set_prefix_from_strings(SerdEnv*       env,
 }
 
 static inline bool
-is_nameChar(const uint8_t c)
+is_nameChar(const char c)
 {
 	return is_alpha(c) || is_digit(c) || c == '_';
 }
@@ -171,7 +171,7 @@ is_nameChar(const uint8_t c)
    TODO: This is more strict than it should be.
 */
 static inline bool
-is_name(const uint8_t* buf, size_t len)
+is_name(const char* buf, size_t len)
 {
 	for (size_t i = 0; i < len; ++i) {
 		if (!is_nameChar(buf[i])) {
@@ -213,7 +213,7 @@ serd_env_expand(const SerdEnv*  env,
                 SerdChunk*      uri_prefix,
                 SerdChunk*      uri_suffix)
 {
-	const uint8_t* const colon = (const uint8_t*)memchr(
+	const char* const colon = (const char*)memchr(
 		curie->buf, ':', curie->n_bytes + 1);
 	if (curie->type != SERD_CURIE || !colon) {
 		return SERD_ERR_BAD_ARG;
@@ -244,7 +244,7 @@ serd_env_expand_node(const SerdEnv*  env,
 			return SERD_NODE_NULL;
 		}
 		const size_t len = prefix.len + suffix.len;
-		uint8_t*     buf = (uint8_t*)malloc(len + 1);
+		char*        buf = (char*)malloc(len + 1);
 		SerdNode     ret = { buf, len, 0, SERD_URI };
 		snprintf((char*)buf, ret.n_bytes + 1, "%s%s", prefix.buf, suffix.buf);
 		return ret;
diff --git a/src/n3.c b/src/n3.c
index bb8d4d9d..51b06d91 100644
--- a/src/n3.c
+++ b/src/n3.c
@@ -847,7 +847,7 @@ read_BLANK_NODE_LABEL(SerdReader* reader, bool* ate_dot)
 	eat_byte_safe(reader, '_');
 	eat_byte_check(reader, ':');
 	Ref ref = push_node(reader, SERD_BLANK,
-	                    reader->bprefix ? (char*)reader->bprefix : "",
+	                    reader->bprefix ? reader->bprefix : "",
 	                    reader->bprefix_len);
 
 	uint8_t c = peek_byte(reader);  // First: (PN_CHARS | '_' | [0-9])
diff --git a/src/node.c b/src/node.c
index 1ea6bd5b..7a520886 100644
--- a/src/node.c
+++ b/src/node.c
@@ -33,7 +33,7 @@
 
 SERD_API
 SerdNode
-serd_node_from_string(SerdType type, const uint8_t* str)
+serd_node_from_string(SerdType type, const char* str)
 {
 	if (!str) {
 		return SERD_NODE_NULL;
@@ -47,7 +47,7 @@ serd_node_from_string(SerdType type, const uint8_t* str)
 
 SERD_API
 SerdNode
-serd_node_from_substring(SerdType type, const uint8_t* str, const size_t len)
+serd_node_from_substring(SerdType type, const char* str, const size_t len)
 {
 	if (!str) {
 		return SERD_NODE_NULL;
@@ -68,7 +68,7 @@ serd_node_copy(const SerdNode* node)
 	}
 
 	SerdNode copy = *node;
-	uint8_t* buf  = (uint8_t*)malloc(copy.n_bytes + 1);
+	char* buf  = (char*)malloc(copy.n_bytes + 1);
 	memcpy(buf, node->buf, copy.n_bytes + 1);
 	copy.buf = buf;
 	return copy;
@@ -106,7 +106,7 @@ serd_uri_string_length(const SerdURI* uri)
 static size_t
 string_sink(const void* buf, size_t len, void* stream)
 {
-	uint8_t** ptr = (uint8_t**)stream;
+	char** ptr = (char**)stream;
 	memcpy(*ptr, buf, len);
 	*ptr += len;
 	return len;
@@ -125,7 +125,7 @@ serd_node_new_uri_from_node(const SerdNode* uri_node,
 
 SERD_API
 SerdNode
-serd_node_new_uri_from_string(const uint8_t* str,
+serd_node_new_uri_from_string(const char*    str,
                               const SerdURI* base,
                               SerdURI*       out)
 {
@@ -140,7 +140,7 @@ serd_node_new_uri_from_string(const uint8_t* str,
 }
 
 static inline bool
-is_uri_path_char(const uint8_t c)
+is_uri_path_char(const char c)
 {
 	if (is_alpha(c) || is_digit(c)) {
 		return true;
@@ -160,23 +160,22 @@ is_uri_path_char(const uint8_t c)
 
 SERD_API
 SerdNode
-serd_node_new_file_uri(const uint8_t* path,
-                       const uint8_t* hostname,
-                       SerdURI*       out,
-                       bool           escape)
+serd_node_new_file_uri(const char* path,
+                       const char* hostname,
+                       SerdURI*    out,
+                       bool        escape)
 {
-	const size_t path_len     = strlen((const char*)path);
-	const size_t hostname_len = hostname ? strlen((const char*)hostname) : 0;
+	const size_t path_len     = strlen(path);
+	const size_t hostname_len = hostname ? strlen(hostname) : 0;
 	const bool   evil         = is_windows_path(path);
 	size_t       uri_len      = 0;
-	uint8_t*     uri          = NULL;
+	char*        uri          = NULL;
 
 	if (path[0] == '/' || is_windows_path(path)) {
 		uri_len = strlen("file://") + hostname_len + evil;
-		uri = (uint8_t*)malloc(uri_len + 1);
-		snprintf((char*)uri, uri_len + 1, "file://%s%s",
-		         hostname ? (const char*)hostname : "",
-		         evil ? "/" : "");
+		uri = (char*)malloc(uri_len + 1);
+		snprintf(uri, uri_len + 1, "file://%s%s",
+		         hostname ? hostname : "", evil ? "/" : "");
 	}
 
 	SerdBuffer buffer = { uri, uri_len };
@@ -196,11 +195,11 @@ serd_node_new_file_uri(const uint8_t* path,
 	serd_buffer_sink_finish(&buffer);
 
 	if (out) {
-		serd_uri_parse((const uint8_t*)buffer.buf, out);
+		serd_uri_parse((const char*)buffer.buf, out);
 	}
 
 	return serd_node_from_substring(
-		SERD_URI, (const uint8_t*)buffer.buf, buffer.len);
+		SERD_URI, (const char*)buffer.buf, buffer.len);
 }
 
 SERD_API
@@ -213,9 +212,9 @@ serd_node_new_uri(const SerdURI* uri, const SerdURI* base, SerdURI* out)
 	}
 
 	const size_t len        = serd_uri_string_length(&abs_uri);
-	uint8_t*     buf        = (uint8_t*)malloc(len + 1);
+	char*        buf        = (char*)malloc(len + 1);
 	SerdNode     node       = { buf, len, 0, SERD_URI };
-	uint8_t*     ptr        = buf;
+	char*        ptr        = buf;
 	const size_t actual_len = serd_uri_serialise(&abs_uri, string_sink, &ptr);
 
 	buf[actual_len] = '\0';
@@ -235,11 +234,11 @@ serd_node_new_relative_uri(const SerdURI* uri,
                            const SerdURI* root,
                            SerdURI*       out)
 {
-	const size_t uri_len  = serd_uri_string_length(uri);
-	const size_t base_len = serd_uri_string_length(base);
-	uint8_t*     buf        = (uint8_t*)malloc(uri_len + base_len + 1);
+	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 };
-	uint8_t*     ptr        = buf;
+	char*        ptr        = buf;
 	const size_t actual_len = serd_uri_serialise_relative(
 		uri, base, root, string_sink, &ptr);
 
@@ -271,7 +270,7 @@ serd_node_new_decimal(double d, unsigned frac_digits)
 	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       = { (const uint8_t*)buf, 0, 0, SERD_LITERAL };
+	SerdNode       node       = { buf, 0, 0, SERD_LITERAL };
 	const double   int_part   = floor(abs_d);
 
 	// Point s to decimal point location
@@ -322,7 +321,7 @@ serd_node_new_integer(int64_t i)
 	int64_t        abs_i  = (i < 0) ? -i : i;
 	const unsigned digits = serd_digits(abs_i);
 	char*          buf    = (char*)calloc(digits + 2, 1);
-	SerdNode       node   = { (const uint8_t*)buf, 0, 0, SERD_LITERAL };
+	SerdNode       node   = { (const char*)buf, 0, 0, SERD_LITERAL };
 
 	// Point s to the end
 	char* s = buf + digits - 1;
@@ -368,7 +367,7 @@ serd_node_new_blob(const void* buf, size_t size, bool wrap_lines)
 {
 	const size_t len  = ((size + 2) / 3) * 4 + (wrap_lines ? (size / 57) : 0);
 	uint8_t*     str  = (uint8_t*)calloc(1, len + 2);
-	SerdNode     node = { str, len, 0, SERD_LITERAL };
+	SerdNode     node = { (const char*)str, len, 0, SERD_LITERAL };
 	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);
@@ -389,7 +388,7 @@ void
 serd_node_free(SerdNode* node)
 {
 	if (node && node->buf) {
-		free((uint8_t*)node->buf);
+		free((char*)node->buf);
 		node->buf = NULL;
 	}
 }
diff --git a/src/reader.c b/src/reader.c
index 4266e128..142622e4 100644
--- a/src/reader.c
+++ b/src/reader.c
@@ -76,7 +76,7 @@ Ref
 push_node_padded(SerdReader* reader, size_t maxlen,
                  SerdType type, const char* str, size_t n_bytes)
 {
-	void* mem = serd_stack_push_aligned(
+	char* mem = (char*)serd_stack_push_aligned(
 		&reader->stack, sizeof(SerdNode) + maxlen + 1, sizeof(SerdNode));
 
 	SerdNode* const node = (SerdNode*)mem;
@@ -85,15 +85,15 @@ push_node_padded(SerdReader* reader, size_t maxlen,
 	node->type    = type;
 	node->buf     = NULL;
 
-	uint8_t* buf = (uint8_t*)(node + 1);
+	char* buf = (char*)(node + 1);
 	memcpy(buf, str, n_bytes + 1);
 
 #ifdef SERD_STACK_CHECK
 	reader->allocs = realloc(
 		reader->allocs, sizeof(reader->allocs) * (++reader->n_allocs));
-	reader->allocs[reader->n_allocs - 1] = ((uint8_t*)mem - reader->stack.buf);
+	reader->allocs[reader->n_allocs - 1] = (mem - reader->stack.buf);
 #endif
-	return (uint8_t*)node - reader->stack.buf;
+	return (char*)node - reader->stack.buf;
 }
 
 Ref
@@ -107,7 +107,7 @@ deref(SerdReader* reader, const Ref ref)
 {
 	if (ref) {
 		SerdNode* node = (SerdNode*)(reader->stack.buf + ref);
-		node->buf = (uint8_t*)node + sizeof(SerdNode);
+		node->buf = (char*)node + sizeof(SerdNode);
 		return node;
 	}
 	return NULL;
@@ -123,8 +123,8 @@ pop_node(SerdReader* reader, Ref ref)
 		--reader->n_allocs;
 #endif
 		SerdNode* const node = deref(reader, ref);
-		uint8_t* const  top  = reader->stack.buf + reader->stack.size;
-		serd_stack_pop_aligned(&reader->stack, top - (uint8_t*)node);
+		char* const     top  = reader->stack.buf + reader->stack.size;
+		serd_stack_pop_aligned(&reader->stack, top - (char*)node);
 	}
 	return 0;
 }
@@ -238,15 +238,15 @@ serd_reader_get_handle(const SerdReader* reader)
 
 SERD_API
 void
-serd_reader_add_blank_prefix(SerdReader*    reader,
-                             const uint8_t* prefix)
+serd_reader_add_blank_prefix(SerdReader* reader,
+                             const char* prefix)
 {
 	free(reader->bprefix);
 	reader->bprefix_len = 0;
 	reader->bprefix     = NULL;
 	if (prefix) {
-		reader->bprefix_len = strlen((const char*)prefix);
-		reader->bprefix     = (uint8_t*)malloc(reader->bprefix_len + 1);
+		reader->bprefix_len = strlen(prefix);
+		reader->bprefix     = (char*)malloc(reader->bprefix_len + 1);
 		memcpy(reader->bprefix, prefix, reader->bprefix_len + 1);
 	}
 }
@@ -262,15 +262,15 @@ serd_reader_set_default_graph(SerdReader*     reader,
 
 SERD_API
 SerdStatus
-serd_reader_read_file(SerdReader*    reader,
-                      const uint8_t* uri)
+serd_reader_read_file(SerdReader* reader,
+                      const char* uri)
 {
-	uint8_t* const path = serd_file_uri_parse(uri, NULL);
+	char* const path = serd_file_uri_parse(uri, NULL);
 	if (!path) {
 		return SERD_ERR_BAD_ARG;
 	}
 
-	FILE* fd = serd_fopen((const char*)path, "rb");
+	FILE* fd = serd_fopen(path, "rb");
 	if (!fd) {
 		free(path);
 		return SERD_ERR_UNKNOWN;
@@ -301,10 +301,10 @@ skip_bom(SerdReader* me)
 
 SERD_API
 SerdStatus
-serd_reader_start_stream(SerdReader*    reader,
-                         FILE*          file,
-                         const uint8_t* name,
-                         bool           bulk)
+serd_reader_start_stream(SerdReader* reader,
+                         FILE*       file,
+                         const char* name,
+                         bool        bulk)
 {
 	return serd_reader_start_source_stream(
 		reader,
@@ -321,7 +321,7 @@ serd_reader_start_source_stream(SerdReader*         reader,
                                 SerdSource          read_func,
                                 SerdStreamErrorFunc error_func,
                                 void*               stream,
-                                const uint8_t*      name,
+                                const char*         name,
                                 size_t              page_size)
 {
 	return serd_byte_source_open_source(
@@ -369,9 +369,9 @@ serd_reader_end_stream(SerdReader* reader)
 
 SERD_API
 SerdStatus
-serd_reader_read_file_handle(SerdReader*    reader,
-                             FILE*          file,
-                             const uint8_t* name)
+serd_reader_read_file_handle(SerdReader* reader,
+                             FILE*       file,
+                             const char* name)
 {
 	return serd_reader_read_source(
 		reader, (SerdSource)fread, (SerdStreamErrorFunc)ferror,
@@ -384,7 +384,7 @@ serd_reader_read_source(SerdReader*         reader,
                         SerdSource          source,
                         SerdStreamErrorFunc error,
                         void*               stream,
-                        const uint8_t*      name,
+                        const char*         name,
                         size_t              page_size)
 {
 	SerdStatus st = serd_reader_start_source_stream(
@@ -403,7 +403,7 @@ serd_reader_read_source(SerdReader*         reader,
 
 SERD_API
 SerdStatus
-serd_reader_read_string(SerdReader* reader, const uint8_t* utf8)
+serd_reader_read_string(SerdReader* reader, const char* utf8)
 {
 	serd_byte_source_open_string(&reader->source, utf8);
 
diff --git a/src/reader.h b/src/reader.h
index 7dc981af..18b587c8 100644
--- a/src/reader.h
+++ b/src/reader.h
@@ -66,7 +66,7 @@ static inline SerdStatus
 push_byte(SerdReader* reader, Ref ref, const uint8_t c)
 {
 	SERD_STACK_ASSERT_TOP(reader, ref);
-	uint8_t* const  s    = serd_stack_push(&reader->stack, 1);
+	char* const     s    = serd_stack_push(&reader->stack, 1);
 	SerdNode* const node = (SerdNode*)(reader->stack.buf + ref);
 	++node->n_bytes;
 	*(s - 1) = c;
diff --git a/src/serd_internal.h b/src/serd_internal.h
index 46b88c83..d678627f 100644
--- a/src/serd_internal.h
+++ b/src/serd_internal.h
@@ -76,9 +76,9 @@ serd_bufalloc(size_t size)
 /* Byte source */
 
 typedef struct {
-	const uint8_t* filename;
-	unsigned       line;
-	unsigned       col;
+	const char* filename;
+	unsigned    line;
+	unsigned    col;
 } Cursor;
 
 typedef struct {
@@ -87,10 +87,10 @@ typedef struct {
 	void*               stream;       ///< Stream (e.g. FILE)
 	size_t              page_size;    ///< Number of bytes to read at a time
 	Cursor              cur;          ///< Cursor for error reporting
-	uint8_t*            file_buf;     ///< Buffer iff reading pages from a file
-	const uint8_t*      read_buf;     ///< Pointer to file_buf or read_byte
+	char*               file_buf;     ///< Buffer iff reading pages from a file
+	const char*         read_buf;     ///< Pointer to file_buf or read_byte
 	size_t              read_head;    ///< Offset into read_buf
-	uint8_t             read_byte;    ///< 1-byte 'buffer' used when not paging
+	char                read_byte;    ///< 1-byte 'buffer' used when not paging
 	bool                from_stream;  ///< True iff reading from `stream`
 	bool                prepared;     ///< True iff prepared for reading
 	bool                eof;          ///< True iff end of file reached
@@ -102,14 +102,14 @@ serd_byte_source_open_file(SerdByteSource* source,
                            bool            bulk);
 
 SerdStatus
-serd_byte_source_open_string(SerdByteSource* source, const uint8_t* utf8);
+serd_byte_source_open_string(SerdByteSource* source, const char* utf8);
 
 SerdStatus
 serd_byte_source_open_source(SerdByteSource*     source,
                              SerdSource          read_func,
                              SerdStreamErrorFunc error_func,
                              void*               stream,
-                             const uint8_t*      name,
+                             const char*         name,
                              size_t              page_size);
 
 SerdStatus
@@ -132,7 +132,7 @@ serd_byte_source_advance(SerdByteSource* source);
 
 /** A dynamic stack in memory. */
 typedef struct {
-	uint8_t* buf;       ///< Stack memory
+	char*    buf;       ///< Stack memory
 	size_t   buf_size;  ///< Allocated size of buf (>= size)
 	size_t   size;      ///< Conceptual size of stack in buf
 } SerdStack;
@@ -144,7 +144,7 @@ static inline SerdStack
 serd_stack_new(size_t size)
 {
 	SerdStack stack;
-	stack.buf       = (uint8_t*)malloc(size);
+	stack.buf       = (char*)malloc(size);
 	stack.buf_size  = size;
 	stack.size      = SERD_STACK_BOTTOM;
 	return stack;
@@ -165,15 +165,15 @@ serd_stack_free(SerdStack* stack)
 	stack->size     = 0;
 }
 
-static inline uint8_t*
+static inline char*
 serd_stack_push(SerdStack* stack, size_t n_bytes)
 {
 	const size_t new_size = stack->size + n_bytes;
 	if (stack->buf_size < new_size) {
 		stack->buf_size += (stack->buf_size >> 1); // *= 1.5
-		stack->buf = (uint8_t*)realloc(stack->buf, stack->buf_size);
+		stack->buf = (char*)realloc(stack->buf, stack->buf_size);
 	}
-	uint8_t* const ret = (stack->buf + stack->size);
+	char* const ret = (stack->buf + stack->size);
 	stack->size = new_size;
 	return ret;
 }
@@ -222,7 +222,7 @@ serd_stack_pop_aligned(SerdStack* stack, size_t n_bytes)
 typedef struct SerdByteSinkImpl {
 	SerdSink sink;
 	void*    stream;
-	uint8_t* buf;
+	char*    buf;
 	size_t   size;
 	size_t   block_size;
 } SerdByteSink;
@@ -236,7 +236,7 @@ serd_byte_sink_new(SerdSink sink, void* stream, size_t block_size)
 	bsink.size       = 0;
 	bsink.block_size = block_size;
 	bsink.buf        = ((block_size > 1)
-	                    ? (uint8_t*)serd_bufalloc(block_size)
+	                    ? (char*)serd_bufalloc(block_size)
 	                    : NULL);
 	return bsink;
 }
@@ -275,7 +275,7 @@ serd_byte_sink_write(const void* buf, size_t len, SerdByteSink* bsink)
 		// Write as much as possible into the remaining buffer space
 		memcpy(bsink->buf + bsink->size, buf, n);
 		bsink->size += n;
-		buf          = (const uint8_t*)buf + n;
+		buf          = (const char*)buf + n;
 		len         -= n;
 
 		// Flush page if buffer is full
@@ -291,21 +291,21 @@ serd_byte_sink_write(const void* buf, size_t len, SerdByteSink* bsink)
 
 /** Return true if `c` lies within [`min`...`max`] (inclusive) */
 static inline bool
-in_range(const uint8_t c, const uint8_t min, const uint8_t max)
+in_range(const char c, const char min, const char max)
 {
 	return (c >= min && c <= max);
 }
 
 /** RFC2234: ALPHA ::= %x41-5A / %x61-7A  ; A-Z / a-z */
 static inline bool
-is_alpha(const uint8_t c)
+is_alpha(const char c)
 {
 	return in_range(c, 'A', 'Z') || in_range(c, 'a', 'z');
 }
 
 /** RFC2234: DIGIT ::= %x30-39  ; 0-9 */
 static inline bool
-is_digit(const uint8_t c)
+is_digit(const char c)
 {
 	return in_range(c, '0', '9');
 }
@@ -336,13 +336,13 @@ is_space(const char c)
 }
 
 static inline bool
-is_base64(const uint8_t c)
+is_base64(const char c)
 {
 	return is_alpha(c) || is_digit(c) || c == '+' || c == '/' || c == '=';
 }
 
 static inline bool
-is_windows_path(const uint8_t* path)
+is_windows_path(const char* path)
 {
 	return is_alpha(path[0]) && (path[1] == ':' || path[1] == '|')
 		&& (path[2] == '/' || path[2] == '\\');
@@ -351,7 +351,7 @@ is_windows_path(const uint8_t* path)
 /* String utilities */
 
 size_t
-serd_substrlen(const uint8_t* str,
+serd_substrlen(const char*    str,
                const size_t   len,
                SerdNodeFlags* flags);
 
@@ -420,7 +420,7 @@ uri_path_len(const SerdURI* uri)
 	return uri->path_base.len + uri->path.len;
 }
 
-static inline uint8_t
+static inline char
 uri_path_at(const SerdURI* uri, size_t i)
 {
 	if (i < uri->path_base.len) {
@@ -525,7 +525,7 @@ struct SerdReaderImpl {
 	unsigned          next_id;
 	SerdStatus        status;
 	uint8_t*          buf;
-	uint8_t*          bprefix;
+	char*             bprefix;
 	size_t            bprefix_len;
 	bool              strict;     ///< True iff strict parsing
 	bool              seen_genid;
diff --git a/src/serdi.c b/src/serdi.c
index 16767ffd..419d3d06 100644
--- a/src/serdi.c
+++ b/src/serdi.c
@@ -130,14 +130,14 @@ main(int argc, char** argv)
 	bool           full_uris     = false;
 	bool           lax           = false;
 	bool           quiet         = false;
-	const uint8_t* in_name       = NULL;
-	const uint8_t* add_prefix    = NULL;
-	const uint8_t* chop_prefix   = NULL;
-	const uint8_t* root_uri      = NULL;
+	const char*    in_name       = NULL;
+	const char*    add_prefix    = NULL;
+	const char*    chop_prefix   = NULL;
+	const char*    root_uri      = NULL;
 	int            a             = 1;
 	for (; a < argc && argv[a][0] == '-'; ++a) {
 		if (argv[a][1] == '\0') {
-			in_name = (const uint8_t*)"(stdin)";
+			in_name = (const char*)"(stdin)";
 			in_fd   = stdin;
 			break;
 		} else if (argv[a][1] == 'a') {
@@ -157,7 +157,7 @@ main(int argc, char** argv)
 		} else if (argv[a][1] == 'v') {
 			return print_version();
 		} else if (argv[a][1] == 's') {
-			in_name = (const uint8_t*)"(string)";
+			in_name = (const char*)"(string)";
 			from_file = false;
 			++a;
 			break;
@@ -177,17 +177,17 @@ main(int argc, char** argv)
 			if (++a == argc) {
 				return missing_arg(argv[0], 'p');
 			}
-			add_prefix = (const uint8_t*)argv[a];
+			add_prefix = (const char*)argv[a];
 		} else if (argv[a][1] == 'c') {
 			if (++a == argc) {
 				return missing_arg(argv[0], 'c');
 			}
-			chop_prefix = (const uint8_t*)argv[a];
+			chop_prefix = (const char*)argv[a];
 		} else if (argv[a][1] == 'r') {
 			if (++a == argc) {
 				return missing_arg(argv[0], 'r');
 			}
-			root_uri = (const uint8_t*)argv[a];
+			root_uri = (const char*)argv[a];
 		} else {
 			SERDI_ERRORF("invalid option -- '%s'\n", argv[a] + 1);
 			return print_usage(argv[0], true);
@@ -199,18 +199,18 @@ main(int argc, char** argv)
 		return 1;
 	}
 
-	const uint8_t* input = (const uint8_t*)argv[a++];
+	const char* input = (const char*)argv[a++];
 	if (from_file) {
 		in_name = in_name ? in_name : input;
 		if (!in_fd) {
 			input = serd_uri_to_path(in_name);
-			if (!input || !(in_fd = serd_fopen((const char*)input, "rb"))) {
+			if (!input || !(in_fd = serd_fopen(input, "rb"))) {
 				return 1;
 			}
 		}
 	}
 
-	if (!input_syntax && !(input_syntax = guess_syntax((const char*)in_name))) {
+	if (!input_syntax && !(input_syntax = guess_syntax(in_name))) {
 		input_syntax = SERD_TRIG;
 	}
 
@@ -225,7 +225,7 @@ main(int argc, char** argv)
 	SerdNode base     = SERD_NODE_NULL;
 	if (a < argc) {  // Base URI given on command line
 		base = serd_node_new_uri_from_string(
-			(const uint8_t*)argv[a], NULL, &base_uri);
+			(const char*)argv[a], NULL, &base_uri);
 	} else if (from_file && in_fd != stdin) {  // Use input file URI
 		base = serd_node_new_file_uri(input, NULL, &base_uri, true);
 	}
diff --git a/src/string.c b/src/string.c
index ee2ac290..81c6ae07 100644
--- a/src/string.c
+++ b/src/string.c
@@ -19,21 +19,21 @@
 #include <math.h>
 
 SERD_API
-const uint8_t*
+const char*
 serd_strerror(SerdStatus status)
 {
 	switch (status) {
-	case SERD_SUCCESS:        return (const uint8_t*)"Success";
-	case SERD_FAILURE:        return (const uint8_t*)"Non-fatal failure";
-	case SERD_ERR_UNKNOWN:    return (const uint8_t*)"Unknown error";
-	case SERD_ERR_BAD_SYNTAX: return (const uint8_t*)"Invalid syntax";
-	case SERD_ERR_BAD_ARG:    return (const uint8_t*)"Invalid argument";
-	case SERD_ERR_NOT_FOUND:  return (const uint8_t*)"Not found";
-	case SERD_ERR_ID_CLASH:   return (const uint8_t*)"Blank node ID clash";
-	case SERD_ERR_BAD_CURIE:  return (const uint8_t*)"Invalid CURIE";
-	case SERD_ERR_INTERNAL:   return (const uint8_t*)"Internal error";
+	case SERD_SUCCESS:        return "Success";
+	case SERD_FAILURE:        return "Non-fatal failure";
+	case SERD_ERR_UNKNOWN:    return "Unknown error";
+	case SERD_ERR_BAD_SYNTAX: return "Invalid syntax";
+	case SERD_ERR_BAD_ARG:    return "Invalid argument";
+	case SERD_ERR_NOT_FOUND:  return "Not found";
+	case SERD_ERR_ID_CLASH:   return "Blank node ID clash";
+	case SERD_ERR_BAD_CURIE:  return "Invalid CURIE";
+	case SERD_ERR_INTERNAL:   return "Internal error";
 	}
-	return (const uint8_t*)"Unknown error";  // never reached
+	return "Unknown error";  // never reached
 }
 
 static inline void
@@ -49,7 +49,7 @@ serd_update_flags(const uint8_t c, SerdNodeFlags* const flags)
 }
 
 size_t
-serd_substrlen(const uint8_t* const str,
+serd_substrlen(const char* const    str,
                const size_t         len,
                SerdNodeFlags* const flags)
 {
@@ -61,12 +61,12 @@ serd_substrlen(const uint8_t* const str,
 		}
 		return i;
 	}
-	return strlen((const char*)str);
+	return strlen(str);
 }
 
 SERD_API
 size_t
-serd_strlen(const uint8_t* str, SerdNodeFlags* flags)
+serd_strlen(const char* str, SerdNodeFlags* flags)
 {
 	if (flags) {
 		size_t i = 0;
@@ -76,7 +76,7 @@ serd_strlen(const uint8_t* str, SerdNodeFlags* flags)
 		}
 		return i;
 	}
-	return strlen((const char*)str);
+	return strlen(str);
 }
 
 static inline double
@@ -163,16 +163,18 @@ decode_chunk(const uint8_t in[4], uint8_t out[3])
 
 SERD_API
 void*
-serd_base64_decode(const uint8_t* str, size_t len, size_t* size)
+serd_base64_decode(const char* str, size_t len, size_t* size)
 {
+	const uint8_t* ustr = (const uint8_t*)str;
+
 	void* buf = malloc((len * 3) / 4 + 2);
 	*size = 0;
 	for (size_t i = 0, j = 0; i < len; j += 3) {
 		uint8_t in[] = "====";
 		size_t  n_in = 0;
 		for (; i < len && n_in < 4; ++n_in) {
-			for (; i < len && !is_base64(str[i]); ++i) {}  // Skip junk
-			in[n_in] = str[i++];
+			for (; i < len && !is_base64(ustr[i]); ++i) {}  // Skip junk
+			in[n_in] = ustr[i++];
 		}
 		if (n_in > 1) {
 			*size += decode_chunk(in, (uint8_t*)buf + j);
diff --git a/src/uri.c b/src/uri.c
index b13a1e6f..46a55675 100644
--- a/src/uri.c
+++ b/src/uri.c
@@ -22,17 +22,17 @@
 // #define URI_DEBUG 1
 
 SERD_API
-const uint8_t*
-serd_uri_to_path(const uint8_t* uri)
+const char*
+serd_uri_to_path(const char* uri)
 {
-	const uint8_t* path = uri;
+	const char* path = uri;
 	if (!is_windows_path(uri) && serd_uri_string_has_scheme(uri)) {
-		if (strncmp((const char*)uri, "file:", 5)) {
+		if (strncmp(uri, "file:", 5)) {
 			fprintf(stderr, "Non-file URI `%s'\n", uri);
 			return NULL;
-		} else if (!strncmp((const char*)uri, "file://localhost/", 17)) {
+		} else if (!strncmp(uri, "file://localhost/", 17)) {
 			path = uri + 16;
-		} else if (!strncmp((const char*)uri, "file://", 7)) {
+		} else if (!strncmp(uri, "file://", 7)) {
 			path = uri + 7;
 		} else {
 			fprintf(stderr, "Invalid file URI `%s'\n", uri);
@@ -46,23 +46,23 @@ serd_uri_to_path(const uint8_t* uri)
 }
 
 SERD_API
-uint8_t*
-serd_file_uri_parse(const uint8_t* uri, uint8_t** hostname)
+char*
+serd_file_uri_parse(const char* uri, char** hostname)
 {
-	const uint8_t* path = uri;
+	const char* path = uri;
 	if (hostname) {
 		*hostname = NULL;
 	}
-	if (!strncmp((const char*)uri, "file://", 7)) {
-		const uint8_t* auth = uri + 7;
+	if (!strncmp(uri, "file://", 7)) {
+		const char* auth = uri + 7;
 		if (*auth == '/') {  // No hostname
 			path = auth;
 		} else {  // Has hostname
-			if (!(path = (const uint8_t*)strchr((const char*)auth, '/'))) {
+			if (!(path = strchr(auth, '/'))) {
 				return NULL;
 			}
 			if (hostname) {
-				*hostname = (uint8_t*)calloc(1, path - auth + 1);
+				*hostname = (char*)calloc(1, path - auth + 1);
 				memcpy(*hostname, auth, path - auth);
 			}
 		}
@@ -73,16 +73,16 @@ serd_file_uri_parse(const uint8_t* uri, uint8_t** hostname)
 	}
 
 	SerdBuffer buffer = { NULL, 0 };
-	for (const uint8_t* s = path; *s; ++s) {
+	for (const char* s = path; *s; ++s) {
 		if (*s == '%') {
 			if (*(s + 1) == '%') {
 				serd_buffer_sink("%", 1, &buffer);
 				++s;
 			} else if (is_hexdig(*(s + 1)) && is_hexdig(*(s + 2))) {
-				const uint8_t code[3] = { *(s + 1), *(s + 2), 0 };
+				const char code[3] = { *(s + 1), *(s + 2), 0 };
 				uint32_t num;
 				sscanf((const char*)code, "%X", &num);
-				const uint8_t c = num;
+				const char c = num;
 				serd_buffer_sink(&c, 1, &buffer);
 				s += 2;
 			} else {
@@ -97,14 +97,14 @@ serd_file_uri_parse(const uint8_t* uri, uint8_t** hostname)
 
 SERD_API
 bool
-serd_uri_string_has_scheme(const uint8_t* utf8)
+serd_uri_string_has_scheme(const char* utf8)
 {
 	// RFC3986: scheme ::= ALPHA *( ALPHA / DIGIT / "+" / "-" / "." )
 	if (!utf8 || !is_alpha(utf8[0])) {
 		return false;  // Invalid scheme initial character, URI is relative
 	}
 
-	for (uint8_t c; (c = *++utf8) != '\0';) {
+	for (char c; (c = *++utf8) != '\0';) {
 		if (!is_uri_scheme_char(c)) {
 			return false;
 		} else if (c == ':') {
@@ -137,11 +137,11 @@ serd_uri_dump(const SerdURI* uri, FILE* file)
 
 SERD_API
 SerdStatus
-serd_uri_parse(const uint8_t* utf8, SerdURI* out)
+serd_uri_parse(const char* utf8, SerdURI* out)
 {
 	*out = SERD_URI_NULL;
 
-	const uint8_t* ptr = utf8;
+	const char* ptr = utf8;
 
 	/* See http://tools.ietf.org/html/rfc3986#section-3
 	   URI = scheme ":" hier-part [ "?" query ] [ "#" fragment ]
@@ -149,7 +149,7 @@ serd_uri_parse(const uint8_t* utf8, SerdURI* out)
 
 	/* S3.1: scheme ::= ALPHA *( ALPHA / DIGIT / "+" / "-" / "." ) */
 	if (is_alpha(*ptr)) {
-		for (uint8_t c = *++ptr; true; c = *++ptr) {
+		for (char c = *++ptr; true; c = *++ptr) {
 			switch (c) {
 			case '\0': case '/': case '?': case '#':
 				ptr = utf8;
@@ -176,7 +176,7 @@ maybe_authority:
 	if (*ptr == '/' && *(ptr + 1) == '/') {
 		ptr += 2;
 		out->authority.buf = ptr;
-		for (uint8_t c; (c = *ptr) != '\0'; ++ptr) {
+		for (char c; (c = *ptr) != '\0'; ++ptr) {
 			switch (c) {
 			case '/': goto path;
 			case '?': goto query;
@@ -199,7 +199,7 @@ path:
 	}
 	out->path.buf = ptr;
 	out->path.len = 0;
-	for (uint8_t c; (c = *ptr) != '\0'; ++ptr) {
+	for (char c; (c = *ptr) != '\0'; ++ptr) {
 		switch (c) {
 		case '?': goto query;
 		case '#': goto fragment;
@@ -215,7 +215,7 @@ path:
 query:
 	if (*ptr == '?') {
 		out->query.buf = ++ptr;
-		for (uint8_t c; (c = *ptr) != '\0'; ++ptr) {
+		for (char c; (c = *ptr) != '\0'; ++ptr) {
 			switch (c) {
 			case '#':
 				goto fragment;
@@ -253,11 +253,11 @@ end:
    @param up Set to the number of up-references (e.g. "../") trimmed
    @return A pointer to the new start of `path`
 */
-static const uint8_t*
-remove_dot_segments(const uint8_t* path, size_t len, size_t* up)
+static const char*
+remove_dot_segments(const char* path, size_t len, size_t* up)
 {
-	const uint8_t*       begin = path;
-	const uint8_t* const end   = path + len;
+	const char*       begin = path;
+	const char* const end   = path + len;
 
 	*up = 0;
 	while (begin < end) {
@@ -317,13 +317,13 @@ remove_dot_segments(const uint8_t* path, size_t len, size_t* up)
 static void
 merge(SerdChunk* base, SerdChunk* path)
 {
-	size_t         up;
-	const uint8_t* begin = remove_dot_segments(path->buf, path->len, &up);
-	const uint8_t* end   = path->buf + path->len;
+	size_t      up;
+	const char* begin = remove_dot_segments(path->buf, path->len, &up);
+	const char* end   = path->buf + path->len;
 
 	if (base->len) {
 		// Find the up'th last slash
-		const uint8_t* base_last = (base->buf + base->len - 1);
+		const char* base_last = (base->buf + base->len - 1);
 		++up;
 		do {
 			if (*base_last == '/') {
diff --git a/src/writer.c b/src/writer.c
index cecaacf5..e7ec0e09 100644
--- a/src/writer.c
+++ b/src/writer.c
@@ -146,7 +146,7 @@ static void
 copy_node(SerdNode* dst, const SerdNode* src)
 {
 	if (src) {
-		dst->buf = (uint8_t*)realloc((char*)dst->buf, src->n_bytes + 1);
+		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;
@@ -207,7 +207,7 @@ uri_must_escape(const uint8_t c)
 }
 
 static size_t
-write_uri(SerdWriter* writer, const uint8_t* utf8, size_t n_bytes)
+write_uri(SerdWriter* writer, const char* utf8, size_t n_bytes)
 {
 	size_t len = 0;
 	for (size_t i = 0; i < n_bytes;) {
@@ -226,7 +226,7 @@ write_uri(SerdWriter* writer, const uint8_t* utf8, size_t n_bytes)
 
 		// Write UTF-8 character
 		size_t size = 0;
-		len += write_character(writer, utf8 + i, &size);
+		len += write_character(writer, (const uint8_t*)utf8 + i, &size);
 		i   += size;
 		if (size == 0) {
 			// Corrupt input, scan to start of next character
@@ -237,7 +237,7 @@ write_uri(SerdWriter* writer, const uint8_t* utf8, size_t n_bytes)
 }
 
 static bool
-lname_must_escape(const uint8_t c)
+lname_must_escape(const char c)
 {
 	/* This arbitrary list of characters, most of which have nothing to do with
 	   Turtle, must be handled as special cases here because the RDF and SPARQL
@@ -258,7 +258,7 @@ lname_must_escape(const uint8_t c)
 }
 
 static size_t
-write_lname(SerdWriter* writer, const uint8_t* utf8, size_t n_bytes)
+write_lname(SerdWriter* writer, const char* utf8, size_t n_bytes)
 {
 	size_t len = 0;
 	for (size_t i = 0; i < n_bytes; ++i) {
@@ -284,7 +284,7 @@ write_lname(SerdWriter* writer, const uint8_t* utf8, size_t n_bytes)
 
 static size_t
 write_text(SerdWriter* writer, TextContext ctx,
-           const uint8_t* utf8, size_t n_bytes)
+           const char* utf8, size_t n_bytes)
 {
 	size_t len = 0;
 	for (size_t i = 0; i < n_bytes;) {
@@ -338,7 +338,8 @@ write_text(SerdWriter* writer, TextContext ctx,
 
 		// Write UTF-8 character
 		size_t size = 0;
-		len += write_character(writer, utf8 + i - 1, &size);
+		len += write_character(writer, (const uint8_t*)utf8 + i - 1, &size);
+
 		if (size == 0) {
 			// Corrupt input, scan to start of next character
 			for (; i < n_bytes && (utf8[i] & 0x80); ++i) {}
@@ -352,7 +353,7 @@ write_text(SerdWriter* writer, TextContext ctx,
 static size_t
 uri_sink(const void* buf, size_t len, void* stream)
 {
-	return write_uri((SerdWriter*)stream, (const uint8_t*)buf, len);
+	return write_uri((SerdWriter*)stream, (const char*)buf, len);
 }
 
 static void
@@ -871,14 +872,14 @@ serd_writer_set_error_sink(SerdWriter*   writer,
 
 SERD_API
 void
-serd_writer_chop_blank_prefix(SerdWriter*    writer,
-                              const uint8_t* prefix)
+serd_writer_chop_blank_prefix(SerdWriter* writer,
+                              const char* prefix)
 {
 	free(writer->bprefix);
 	writer->bprefix_len = 0;
 	writer->bprefix     = NULL;
 	if (prefix) {
-		writer->bprefix_len = strlen((const char*)prefix);
+		writer->bprefix_len = strlen(prefix);
 		writer->bprefix     = (uint8_t*)malloc(writer->bprefix_len + 1);
 		memcpy(writer->bprefix, prefix, writer->bprefix_len + 1);
 	}
@@ -985,9 +986,9 @@ serd_buffer_sink(const void* buf, size_t len, void* stream)
 }
 
 SERD_API
-uint8_t*
+char*
 serd_buffer_sink_finish(SerdBuffer* stream)
 {
 	serd_buffer_sink("", 1, stream);
-	return (uint8_t*)stream->buf;
+	return (char*)stream->buf;
 }
diff --git a/tests/serd_test.c b/tests/serd_test.c
index 71801c1b..b3270cde 100644
--- a/tests/serd_test.c
+++ b/tests/serd_test.c
@@ -25,8 +25,6 @@
 
 #include "test_utils.h"
 
-#define USTR(s) ((const uint8_t*)(s))
-
 #ifndef INFINITY
 #    define INFINITY (DBL_MAX + DBL_MAX)
 #endif
@@ -89,11 +87,9 @@ check_file_uri(const char* hostname,
 		expected_path = path;
 	}
 
-	SerdNode node = serd_node_new_file_uri(
-		USTR(path), USTR(hostname), 0, escape);
-
-	uint8_t* out_hostname = NULL;
-	uint8_t* out_path     = serd_file_uri_parse(node.buf, &out_hostname);
+	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);
 	int      ret          = 0;
 	if (strcmp((const char*)node.buf, expected_uri)) {
 		ret = FAILF("Bad URI %s != %s\n", node.buf, expected_uri);
@@ -156,13 +152,13 @@ main(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((const char*)node.buf, (const char*)dbl_test_strs[i])
-			: ((const char*)node.buf == dbl_test_strs[i]);
+			? !strcmp(node.buf, dbl_test_strs[i])
+			: (node.buf == dbl_test_strs[i]);
 		if (!pass) {
 			FAILF("Serialised `%s' != %s\n",
 			      node.buf, dbl_test_strs[i]);
 		}
-		const size_t len = node.buf ? strlen((const char*)node.buf) : 0;
+		const size_t len = node.buf ? strlen(node.buf) : 0;
 		if (node.n_bytes != len) {
 			FAILF("Length %zu != %zu\n",
 			      node.n_bytes, len);
@@ -186,7 +182,7 @@ main(void)
 			FAILF("Serialised `%s' != %s\n",
 			      node.buf, int_test_strs[i]);
 		}
-		const size_t len = strlen((const char*)node.buf);
+		const size_t len = strlen(node.buf);
 		if (node.n_bytes != len) {
 			FAILF("Length %zu,%zu != %zu\n",
 			      node.n_bytes, len);
@@ -225,7 +221,7 @@ main(void)
 	const uint8_t str[] = { '"', '5', 0xE2, 0x82, 0xAC, '"', '\n', 0 };
 
 	SerdNodeFlags flags;
-	size_t        n_bytes = serd_strlen(str, &flags);
+	size_t        n_bytes = serd_strlen((const char*)str, &flags);
 	if (n_bytes != 7 || flags != (SERD_HAS_QUOTE|SERD_HAS_NEWLINE)) {
 		FAILF("Bad serd_strlen(%s) n_bytes=%zu flags=%u\n",
 		      str, n_bytes, flags);
@@ -233,8 +229,8 @@ main(void)
 
 	// Test serd_strerror
 
-	const uint8_t* msg = NULL;
-	if (strcmp((const char*)(msg = serd_strerror(SERD_SUCCESS)), "Success")) {
+	const char* msg = NULL;
+	if (strcmp((msg = serd_strerror(SERD_SUCCESS)), "Success")) {
 		FAILF("Bad message `%s' for SERD_SUCCESS\n", msg);
 	}
 	for (int i = SERD_FAILURE; i <= SERD_ERR_INTERNAL; ++i) {
@@ -247,36 +243,36 @@ main(void)
 
 	// Test serd_uri_to_path
 
-	const uint8_t* uri = (const uint8_t*)"file:///home/user/foo.ttl";
-	if (strcmp((const char*)serd_uri_to_path(uri), "/home/user/foo.ttl")) {
+	const char* uri = "file:///home/user/foo.ttl";
+	if (strcmp(serd_uri_to_path(uri), "/home/user/foo.ttl")) {
 		FAILF("Bad path %s for %s\n", serd_uri_to_path(uri), uri);
 	}
-	uri = (const uint8_t*)"file://localhost/home/user/foo.ttl";
-	if (strcmp((const char*)serd_uri_to_path(uri), "/home/user/foo.ttl")) {
+	uri = "file://localhost/home/user/foo.ttl";
+	if (strcmp(serd_uri_to_path(uri), "/home/user/foo.ttl")) {
 		FAILF("Bad path %s for %s\n", serd_uri_to_path(uri), uri);
 	}
-	uri = (const uint8_t*)"file:illegal/file/uri";
+	uri = "file:illegal/file/uri";
 	if (serd_uri_to_path(uri)) {
 		FAILF("Converted invalid URI `%s' to path `%s'\n",
 		      uri, serd_uri_to_path(uri));
 	}
-	uri = (const uint8_t*)"file:///c:/awful/system";
+	uri = "file:///c:/awful/system";
 	if (strcmp((const char*)serd_uri_to_path(uri), "c:/awful/system")) {
 		FAILF("Bad path %s for %s\n", serd_uri_to_path(uri), uri);
 	}
-	uri = (const uint8_t*)"file:///c:awful/system";
+	uri = "file:///c:awful/system";
 	if (strcmp((const char*)serd_uri_to_path(uri), "/c:awful/system")) {
 		FAILF("Bad path %s for %s\n", serd_uri_to_path(uri), uri);
 	}
-	uri = (const uint8_t*)"file:///0/1";
+	uri = "file:///0/1";
 	if (strcmp((const char*)serd_uri_to_path(uri), "/0/1")) {
 		FAILF("Bad path %s for %s\n", serd_uri_to_path(uri), uri);
 	}
-	uri = (const uint8_t*)"C:\\Windows\\Sucks";
+	uri = "C:\\Windows\\Sucks";
 	if (strcmp((const char*)serd_uri_to_path(uri), "C:\\Windows\\Sucks")) {
 		FAILF("Bad path %s for %s\n", serd_uri_to_path(uri), uri);
 	}
-	uri = (const uint8_t*)"C|/Windows/Sucks";
+	uri = "C|/Windows/Sucks";
 	if (strcmp((const char*)serd_uri_to_path(uri), "C|/Windows/Sucks")) {
 		FAILF("Bad path %s for %s\n", serd_uri_to_path(uri), uri);
 	}
@@ -300,9 +296,8 @@ main(void)
 	}
 
 	// Test tolerance of parsing junk URI escapes
-
-	uint8_t* out_path = serd_file_uri_parse(USTR("file:///foo/%0Xbar"), NULL);
-	if (strcmp((const char*)out_path, "/foo/bar")) {
+	char* out_path = serd_file_uri_parse("file:///foo/%0Xbar", NULL);
+	if (strcmp(out_path, "/foo/bar")) {
 		FAILF("bad tolerance of junk escape: `%s'\n", out_path);
 	}
 	free(out_path);
@@ -310,13 +305,13 @@ main(void)
 	// Test serd_node_equals
 
 	const uint8_t replacement_char_str[] = { 0xEF, 0xBF, 0xBD, 0 };
-	SerdNode lhs = serd_node_from_string(SERD_LITERAL, replacement_char_str);
-	SerdNode rhs = serd_node_from_string(SERD_LITERAL, USTR("123"));
+	SerdNode lhs = serd_node_from_string(SERD_LITERAL, (const char*)replacement_char_str);
+	SerdNode rhs = serd_node_from_string(SERD_LITERAL, "123");
 	if (serd_node_equals(&lhs, &rhs)) {
 		FAILF("%s == %s\n", lhs.buf, rhs.buf);
 	}
 
-	SerdNode qnode = serd_node_from_string(SERD_CURIE, USTR("foo:bar"));
+	SerdNode qnode = serd_node_from_string(SERD_CURIE, "foo:bar");
 	if (serd_node_equals(&lhs, &qnode)) {
 		FAILF("%s == %s\n", lhs.buf, qnode.buf);
 	}
@@ -332,7 +327,7 @@ main(void)
 
 	// Test serd_node_from_string
 
-	SerdNode node = serd_node_from_string(SERD_LITERAL, (const uint8_t*)"hello\"");
+	SerdNode node = serd_node_from_string(SERD_LITERAL, "hello\"");
 	if (node.n_bytes != 6 || node.flags != SERD_HAS_QUOTE
 	    || strcmp((const char*)node.buf, "hello\"")) {
 		FAILF("Bad node %s %zu %d %d\n",
@@ -351,14 +346,14 @@ main(void)
 		FAIL("Successfully created node from NULL substring\n");
 	}
 
-	SerdNode a_b = serd_node_from_substring(SERD_LITERAL, USTR("a\"bc"), 3);
+	SerdNode a_b = serd_node_from_substring(SERD_LITERAL, "a\"bc", 3);
 	if (a_b.n_bytes != 3 || a_b.flags != SERD_HAS_QUOTE
 	    || strncmp((const char*)a_b.buf, "a\"b", 3)) {
 		FAILF("Bad node %s %zu %d %d\n",
 		      a_b.buf, a_b.n_bytes, a_b.flags, a_b.type);
 	}
 
-	a_b = serd_node_from_substring(SERD_LITERAL, USTR("a\"bc"), 10);
+	a_b = serd_node_from_substring(SERD_LITERAL, "a\"bc", 10);
 	if (a_b.n_bytes != 4 || a_b.flags != SERD_HAS_QUOTE
 	    || strncmp((const char*)a_b.buf, "a\"bc", 4)) {
 		FAILF("Bad node %s %zu %zu %d %d\n",
@@ -373,10 +368,10 @@ main(void)
 	}
 
 	SerdURI base_uri;
-	SerdNode base = serd_node_new_uri_from_string(USTR("http://example.org/"),
+	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(USTR(""), &base_uri, NULL);
+	SerdNode nil2 = serd_node_new_uri_from_string("", &base_uri, NULL);
 	if (nil.type != SERD_URI || strcmp((const char*)nil.buf, (const char*)base.buf) ||
 	    nil2.type != SERD_URI || strcmp((const char*)nil2.buf, (const char*)base.buf)) {
 		FAILF("URI %s != base %s\n", nil.buf, base.buf);
@@ -385,7 +380,7 @@ main(void)
 	serd_node_free(&nil2);
 
 	// Test serd_node_new_relative_uri
-	SerdNode abs = serd_node_from_string(SERD_URI, USTR("http://example.org/foo/bar"));
+	SerdNode abs = serd_node_from_string(SERD_URI, "http://example.org/foo/bar");
 	SerdURI  abs_uri;
 	serd_uri_parse(abs.buf, &abs_uri);
 
@@ -400,11 +395,11 @@ main(void)
 
 	// Test SerdEnv
 
-	SerdNode u   = serd_node_from_string(SERD_URI, USTR("http://example.org/foo"));
-	SerdNode b   = serd_node_from_string(SERD_CURIE, USTR("invalid"));
-	SerdNode c   = serd_node_from_string(SERD_CURIE, USTR("eg.2:b"));
+	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);
-	serd_env_set_prefix_from_strings(env, USTR("eg.2"), USTR("http://example.org/"));
+	serd_env_set_prefix_from_strings(env, "eg.2", "http://example.org/");
 
 	if (!serd_env_set_base_uri(env, NULL)) {
 		FAIL("Successfully set NULL base URI\n");
@@ -434,7 +429,7 @@ main(void)
 	}
 	serd_node_free(&xu);
 
-	SerdNode badpre = serd_node_from_string(SERD_CURIE, USTR("hm:what"));
+	SerdNode badpre = serd_node_from_string(SERD_CURIE, "hm:what");
 	SerdNode xbadpre = serd_env_expand_node(env, &badpre);
 	if (!serd_node_equals(&xbadpre, &SERD_NODE_NULL)) {
 		FAILF("Expanded invalid curie %s\n", badpre.buf);
@@ -450,19 +445,19 @@ main(void)
 		FAIL("Set NULL prefix\n");
 	}
 
-	const SerdNode lit = serd_node_from_string(SERD_LITERAL, USTR("hello"));
+	const SerdNode lit = serd_node_from_string(SERD_LITERAL, "hello");
 	if (!serd_env_set_prefix(env, &b, &lit)) {
 		FAIL("Set prefix to literal\n");
 	}
 
 	int n_prefixes = 0;
-	serd_env_set_prefix_from_strings(env, USTR("eg.2"), USTR("http://example.org/"));
+	serd_env_set_prefix_from_strings(env, "eg.2", "http://example.org/");
 	serd_env_foreach(env, count_prefixes, &n_prefixes);
 	if (n_prefixes != 1) {
 		FAILF("Bad prefix count %d\n", n_prefixes);
 	}
 
-	SerdNode shorter_uri = serd_node_from_string(SERD_URI, USTR("urn:foo"));
+	SerdNode shorter_uri = serd_node_from_string(SERD_URI, "urn:foo");
 	SerdNode prefix_name;
 	if (serd_env_qualify(env, &shorter_uri, &prefix_name, &suffix)) {
 		FAILF("Qualified %s\n", shorter_uri.buf);
@@ -482,7 +477,7 @@ main(void)
 		FAIL("Failed to create writer\n");
 	}
 
-	serd_writer_chop_blank_prefix(writer, USTR("tmp"));
+	serd_writer_chop_blank_prefix(writer, "tmp");
 	serd_writer_chop_blank_prefix(writer, NULL);
 
 	if (!serd_writer_set_base_uri(writer, &lit)) {
@@ -495,10 +490,10 @@ main(void)
 		FAIL("Writer has incorrect env\n");
 	}
 
-	uint8_t buf[] = { 0x80, 0, 0, 0, 0 };
-	SerdNode s = serd_node_from_string(SERD_URI, USTR(""));
-	SerdNode p = serd_node_from_string(SERD_URI, USTR("http://example.org/pred"));
-	SerdNode o = serd_node_from_string(SERD_LITERAL, buf);
+	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);
 
 	// Write 3 invalid statements (should write nothing)
 	const SerdNode* junk[][5] = { { &s, &p, NULL, NULL, NULL },
@@ -519,8 +514,8 @@ main(void)
 		}
 	}
 
-	const SerdNode t = serd_node_from_string(SERD_URI, USTR("urn:Type"));
-	const SerdNode l = serd_node_from_string(SERD_LITERAL, USTR("en"));
+	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 },
@@ -540,9 +535,9 @@ main(void)
 	}
 
 	// 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, bad_str);
-	SerdNode      bad_uri   = serd_node_from_string(SERD_URI, bad_str);
+	const char bad_str[] = { (char)0xFF, (char)0x90, 'h', 'i', 0 };
+	SerdNode   bad_lit   = serd_node_from_string(SERD_LITERAL, bad_str);
+	SerdNode   bad_uri   = serd_node_from_string(SERD_URI, bad_str);
 	if (serd_writer_write_statement(writer, 0, NULL,
 	                                &s, &p, &bad_lit, NULL, NULL)) {
 		FAIL("Failed to write junk UTF-8 literal\n");
@@ -552,7 +547,7 @@ main(void)
 	}
 
 	// Write 1 valid statement
-	o = serd_node_from_string(SERD_LITERAL, USTR("hello"));
+	o = serd_node_from_string(SERD_LITERAL, "hello");
 	if (serd_writer_write_statement(writer, 0, NULL,
 	                                &s, &p, &o, NULL, NULL)) {
 		FAIL("Failed to write valid statement\n");
@@ -565,13 +560,13 @@ main(void)
 	writer = serd_writer_new(
 		SERD_TURTLE, (SerdStyle)0, env, NULL, serd_buffer_sink, &buffer);
 
-	o = serd_node_from_string(SERD_URI, USTR("http://example.org/base"));
+	o = serd_node_from_string(SERD_URI, "http://example.org/base");
 	if (serd_writer_set_base_uri(writer, &o)) {
 		FAIL("Failed to write to chunk sink\n");
 	}
 
 	serd_writer_free(writer);
-	uint8_t* out = serd_buffer_sink_finish(&buffer);
+	char* out = serd_buffer_sink_finish(&buffer);
 
 	if (strcmp((const char*)out, "@base <http://example.org/base> .\n")) {
 		FAILF("Incorrect buffer output:\n%s\n", buffer.buf);
@@ -593,20 +588,20 @@ main(void)
 		FAIL("Corrupt reader handle\n");
 	}
 
-	SerdNode g = serd_node_from_string(SERD_URI, USTR("http://example.org/"));
+	SerdNode g = serd_node_from_string(SERD_URI, "http://example.org/");
 	serd_reader_set_default_graph(reader, &g);
-	serd_reader_add_blank_prefix(reader, USTR("tmp"));
+	serd_reader_add_blank_prefix(reader, "tmp");
 	serd_reader_add_blank_prefix(reader, NULL);
 
-	if (!serd_reader_read_file(reader, USTR("http://notafile"))) {
+	if (!serd_reader_read_file(reader, "http://notafile")) {
 		FAIL("Apparently read an http URI\n");
-	} else if (!serd_reader_read_file(reader, USTR("file:///better/not/exist"))) {
+	} else if (!serd_reader_read_file(reader, "file:///better/not/exist")) {
 		FAIL("Apparently read a non-existent file\n");
-	} else if (!serd_reader_read_file(reader, USTR("file://"))) {
+	} else if (!serd_reader_read_file(reader, "file://")) {
 		FAIL("Apparently read a file with no path\n");
 	}
 
-	const SerdStatus st = serd_reader_read_file(reader, USTR(path));
+	const SerdStatus st = serd_reader_read_file(reader, path);
 	if (st) {
 		FAILF("Error reading file (%s)\n", serd_strerror(st));
 	} else if (rt->n_statements != 13) {
@@ -616,7 +611,7 @@ main(void)
 		FAILF("Bad graph %p\n", rt->graph);
 	}
 
-	if (!serd_reader_read_string(reader, USTR("This isn't Turtle at all."))) {
+	if (!serd_reader_read_string(reader, "This isn't Turtle at all.")) {
 		FAIL("Parsed invalid string successfully.\n");
 	}