Use descriptive return codes instead of bool

git-svn-id: http://svn.drobilla.net/serd/trunk@154 490d8e77-9747-427b-9fa3-0b8f29cee8a0

7 files changed, 100 insertions, 99 deletions

diff --git a/serd/serd.h b/serd/serd.h
index d4326c2f..7580207d 100644
--- a/serd/serd.h
+++ b/serd/serd.h
@@ -90,6 +90,18 @@ typedef struct SerdReadStateImpl SerdReadState;
 typedef struct SerdWriterImpl SerdWriter;
 
 /**
+   Return status code.
+*/
+typedef enum {
+	SERD_SUCCESS        = 0,  /**< No error */
+	SERD_FAILURE        = 1,  /**< Non-fatal failure */
+	SERD_ERR_UNKNOWN    = 2,  /**< Unknown error */
+	SERD_ERR_BAD_SYNTAX = 3,  /**< Invalid syntax */
+	SERD_ERR_BAD_ARG    = 3,  /**< Invalid argument */
+	SERD_ERR_NOT_FOUND  = 4   /**< Not found */
+} SerdStatus;
+
+/**
    RDF syntax type.
 */
 typedef enum {
@@ -249,7 +261,7 @@ serd_uri_string_has_scheme(const uint8_t* utf8);
    Parse @a utf8, writing result to @a out.
 */
 SERD_API
-bool
+SerdStatus
 serd_uri_parse(const uint8_t* utf8, SerdURI* out);
 
 /**
@@ -357,30 +369,30 @@ serd_node_free(SerdNode* node);
 
    Called whenever the base URI of the serialisation changes.
 */
-typedef bool (*SerdBaseSink)(void*           handle,
-                             const SerdNode* uri);
+typedef SerdStatus (*SerdBaseSink)(void*           handle,
+                                   const SerdNode* uri);
 
 /**
    Sink (callback) for namespace definitions.
 
    Called whenever a prefix is defined in the serialisation.
 */
-typedef bool (*SerdPrefixSink)(void*           handle,
-                               const SerdNode* name,
-                               const SerdNode* uri);
+typedef SerdStatus (*SerdPrefixSink)(void*           handle,
+                                     const SerdNode* name,
+                                     const SerdNode* uri);
 
 /**
    Sink (callback) for statements.
 
    Called for every RDF statement in the serialisation.
 */
-typedef bool (*SerdStatementSink)(void*           handle,
-                                  const SerdNode* graph,
-                                  const SerdNode* subject,
-                                  const SerdNode* predicate,
-                                  const SerdNode* object,
-                                  const SerdNode* object_datatype,
-                                  const SerdNode* object_lang);
+typedef SerdStatus (*SerdStatementSink)(void*           handle,
+                                        const SerdNode* graph,
+                                        const SerdNode* subject,
+                                        const SerdNode* predicate,
+                                        const SerdNode* object,
+                                        const SerdNode* object_datatype,
+                                        const SerdNode* object_lang);
 
 /**
    Sink (callback) for anonymous node end markers.
@@ -389,8 +401,8 @@ typedef bool (*SerdStatementSink)(void*           handle,
    @a value will no longer be referred to by any future statements
    (i.e. the anonymous serialisation of the node is finished).
 */
-typedef bool (*SerdEndSink)(void*           handle,
-                            const SerdNode* node);
+typedef SerdStatus (*SerdEndSink)(void*           handle,
+                                  const SerdNode* node);
 
 /**
    @}
@@ -435,7 +447,7 @@ serd_env_qualify(const SerdEnv*  env,
    Expand @a curie.
 */
 SERD_API
-bool
+SerdStatus
 serd_env_expand(const SerdEnv*  env,
                 const SerdNode* curie,
                 SerdChunk*      uri_prefix,
@@ -486,7 +498,7 @@ serd_reader_set_blank_prefix(SerdReader*    reader,
    Read @a file.
 */
 SERD_API
-bool
+SerdStatus
 serd_reader_read_file(SerdReader*    reader,
                       FILE*          file,
                       const uint8_t* name);
@@ -495,7 +507,7 @@ serd_reader_read_file(SerdReader*    reader,
    Read @a utf8.
 */
 SERD_API
-bool
+SerdStatus
 serd_reader_read_string(SerdReader* me, const uint8_t* utf8);
 
 /**
@@ -543,7 +555,7 @@ serd_read_state_get_base_uri(SerdReadState* state,
    Set the current base URI.
 */
 SERD_API
-bool
+SerdStatus
 serd_read_state_set_base_uri(SerdReadState*  state,
                              const SerdNode* uri_node);
 
@@ -551,7 +563,7 @@ serd_read_state_set_base_uri(SerdReadState*  state,
    Set a namespace prefix.
 */
 SERD_API
-bool
+SerdStatus
 serd_read_state_set_prefix(SerdReadState*  state,
                            const SerdNode* name,
                            const SerdNode* uri_node);
@@ -585,7 +597,7 @@ serd_writer_free(SerdWriter* writer);
    Set the current output base URI (and emit directive if applicable).
 */
 SERD_API
-void
+SerdStatus
 serd_writer_set_base_uri(SerdWriter*    writer,
                          const SerdURI* uri);
 
@@ -593,7 +605,7 @@ serd_writer_set_base_uri(SerdWriter*    writer,
    Set a namespace prefix (and emit directive if applicable).
 */
 SERD_API
-bool
+SerdStatus
 serd_writer_set_prefix(SerdWriter*     writer,
                        const SerdNode* name,
                        const SerdNode* uri);
@@ -602,7 +614,7 @@ serd_writer_set_prefix(SerdWriter*     writer,
    Write a statement.
 */
 SERD_API
-bool
+SerdStatus
 serd_writer_write_statement(SerdWriter*     writer,
                             const SerdNode* graph,
                             const SerdNode* subject,
@@ -615,7 +627,7 @@ serd_writer_write_statement(SerdWriter*     writer,
    Mark the end of an anonymous node's description.
 */
 SERD_API
-bool
+SerdStatus
 serd_writer_end_anon(SerdWriter*     writer,
                      const SerdNode* node);
 
@@ -623,7 +635,7 @@ serd_writer_end_anon(SerdWriter*     writer,
    Finish a write.
 */
 SERD_API
-void
+SerdStatus
 serd_writer_finish(SerdWriter* writer);
 
 /**
diff --git a/src/env.c b/src/env.c
index 8e831d53..d8a6508d 100644
--- a/src/env.c
+++ b/src/env.c
@@ -112,7 +112,7 @@ serd_env_qualify(const SerdEnv*  env,
 }
 
 SERD_API
-bool
+SerdStatus
 serd_env_expand(const SerdEnv*  env,
                 const SerdNode* qname,
                 SerdChunk*      uri_prefix,
@@ -120,7 +120,7 @@ serd_env_expand(const SerdEnv*  env,
 {
 	const uint8_t* const colon = memchr(qname->buf, ':', qname->n_bytes);
 	if (!colon) {
-		return false;  // Illegal qname
+		return SERD_ERR_BAD_ARG;  // Illegal qname
 	}
 
 	const size_t            name_len = colon - qname->buf;
@@ -130,9 +130,9 @@ serd_env_expand(const SerdEnv*  env,
 		uri_prefix->len = prefix->uri.n_bytes - 1;
 		uri_suffix->buf = colon + 1;
 		uri_suffix->len = qname->n_bytes - (colon - qname->buf) - 2;
-		return true;
+		return SERD_SUCCESS;
 	}
-	return false;
+	return SERD_ERR_NOT_FOUND;
 }
 
 SERD_API
diff --git a/src/node.c b/src/node.c
index 7a7a7642..b262ad3a 100644
--- a/src/node.c
+++ b/src/node.c
@@ -100,7 +100,7 @@ serd_node_new_uri_from_string(const uint8_t* str,
 		return serd_node_new_uri(base, NULL, out);  // Empty URI => Base URI
 	} else {
 		SerdURI uri;
-		if (serd_uri_parse(str, &uri)) {
+		if (!serd_uri_parse(str, &uri)) {
 			return serd_node_new_uri(&uri, base, out);  // Resolve/Serialise
 		}
 	}
@@ -129,7 +129,7 @@ serd_node_new_uri(const SerdURI* uri, const SerdURI* base, SerdURI* out)
 	node.n_chars    = actual_len;
 
 	// FIXME: double parse
-	if (!serd_uri_parse(buf, out)) {
+	if (serd_uri_parse(buf, out)) {
 		fprintf(stderr, "Failed to parse URI <%s>\n", buf);
 		return SERD_NODE_NULL;
 	}
diff --git a/src/reader.c b/src/reader.c
index 8dec46c7..6d9cc599 100644
--- a/src/reader.c
+++ b/src/reader.c
@@ -98,12 +98,6 @@ struct SerdReadStateImpl {
 	SerdURI  base_uri;
 };
 
-typedef enum {
-	SERD_SUCCESS = 0,  ///< Completed successfully
-	SERD_FAILURE = 1,  ///< Non-fatal failure
-	SERD_ERROR   = 2,  ///< Fatal error
-} SerdStatus;
-
 static int
 error(SerdReader* reader, const char* fmt, ...)
 {
@@ -301,13 +295,13 @@ emit_statement(SerdReader* reader,
 	const SerdNode object          = public_node(reader, o);
 	const SerdNode object_datatype = public_node_from_ref(reader, SERD_URI, o->datatype);
 	const SerdNode object_lang     = public_node_from_ref(reader, SERD_LITERAL, o->lang);
-	return reader->statement_sink(reader->handle,
-	                              &graph,
-	                              &subject,
-	                              &predicate,
-	                              &object,
-	                              &object_datatype,
-	                              &object_lang);
+	return !reader->statement_sink(reader->handle,
+	                               &graph,
+	                               &subject,
+	                               &predicate,
+	                               &object,
+	                               &object_datatype,
+	                               &object_lang);
 }
 
 static bool read_collection(SerdReader* reader, ReadContext ctx, Node* dest);
@@ -449,11 +443,11 @@ read_character(SerdReader* reader, Ref dest)
 	switch (c) {
 	case '\0':
 		error(reader, "unexpected end of file\n", peek_byte(reader));
-		return SERD_ERROR;
+		return SERD_ERR_BAD_SYNTAX;
 	default:
 		if (c < 0x20) {  // ASCII control character
 			error(reader, "unexpected control character\n");
-			return SERD_ERROR;
+			return SERD_ERR_BAD_SYNTAX;
 		} else if (c <= 0x7E) {  // Printable ASCII
 			push_byte(reader, dest, eat_byte(reader, c));
 			return SERD_SUCCESS;
@@ -467,7 +461,7 @@ read_character(SerdReader* reader, Ref dest)
 				size = 4;
 			} else {
 				error(reader, "invalid character\n");
-				return SERD_ERROR;
+				return SERD_ERR_BAD_SYNTAX;
 			}
 			for (unsigned i = 0; i < size; ++i) {
 				push_byte(reader, dest, eat_byte(reader, peek_byte(reader)));
@@ -489,7 +483,7 @@ read_echaracter(SerdReader* reader, Ref dest)
 			return SERD_SUCCESS;
 		} else {
 			error(reader, "illegal escape `\\%c'\n", peek_byte(reader));
-			return SERD_ERROR;
+			return SERD_ERR_BAD_SYNTAX;
 		}
 	default:
 		return read_character(reader, dest);
@@ -520,7 +514,7 @@ read_lcharacter(SerdReader* reader, Ref dest)
 			return SERD_SUCCESS;
 		} else {
 			error(reader, "illegal escape `\\%c'\n", peek_byte(reader));
-			return SERD_ERROR;
+			return SERD_ERR_BAD_SYNTAX;
 		}
 	case 0x9: case 0xA: case 0xD:
 		push_byte(reader, dest, eat_byte(reader, c));
@@ -542,7 +536,7 @@ read_scharacter(SerdReader* reader, Ref dest)
 			return SERD_SUCCESS;
 		} else {
 			error(reader, "illegal escape `\\%c'\n", peek_byte(reader));
-			return SERD_ERROR;
+			return SERD_ERR_BAD_SYNTAX;
 		}
 	case '\"':
 		return SERD_FAILURE;
@@ -622,7 +616,7 @@ read_longString(SerdReader* reader)
 	Ref        str = push_string(reader, "", 1);
 	SerdStatus st;
 	while (!(st = read_lcharacter(reader, str))) {}
-	if (st != SERD_ERROR) {
+	if (st < SERD_ERR_UNKNOWN) {
 		return str;
 	}
 	pop_string(reader, str);
@@ -637,7 +631,7 @@ read_string(SerdReader* reader)
 	Ref        str = push_string(reader, "", 1);
 	SerdStatus st;
 	while (!(st = read_scharacter(reader, str))) {}
-	if (st != SERD_ERROR) {
+	if (st < SERD_ERR_UNKNOWN) {
 		eat_byte(reader, '\"');
 		return str;
 	}
@@ -670,7 +664,7 @@ read_relativeURI(SerdReader* reader)
 	Ref str = push_string(reader, "", 1);
 	SerdStatus st;
 	while (!(st = read_ucharacter(reader, str))) {}
-	if (st != SERD_ERROR) {
+	if (st < SERD_ERR_UNKNOWN) {
 		return str;
 	}
 	pop_string(reader, str);
@@ -1292,7 +1286,7 @@ read_prefixID(SerdReader* reader)
 	TRY_THROW(uri = read_uriref(reader));
 	const SerdNode name_node = public_node_from_ref(reader, SERD_LITERAL, name);
 	const SerdNode uri_node  = public_node_from_ref(reader, SERD_URI, uri);
-	ret = reader->prefix_sink(reader->handle, &name_node, &uri_node);
+	ret = !reader->prefix_sink(reader->handle, &name_node, &uri_node);
 	pop_string(reader, uri);
 except:
 	pop_string(reader, name);
@@ -1409,7 +1403,7 @@ serd_reader_set_blank_prefix(SerdReader*    reader,
 }
 
 SERD_API
-bool
+SerdStatus
 serd_reader_read_file(SerdReader* me, FILE* file, const uint8_t* name)
 {
 	const Cursor cur = { name, 1, 1 };
@@ -1432,11 +1426,11 @@ serd_reader_read_file(SerdReader* me, FILE* file, const uint8_t* name)
 	free(me->read_buf - READ_BUF_LEN);
 	me->fd       = 0;
 	me->read_buf = NULL;
-	return ret;
+	return ret ? SERD_SUCCESS : SERD_ERR_UNKNOWN;
 }
 
 SERD_API
-bool
+SerdStatus
 serd_reader_read_string(SerdReader* me, const uint8_t* utf8)
 {
 	const Cursor cur = { (const uint8_t*)"(string)", 1, 1 };
@@ -1450,7 +1444,7 @@ serd_reader_read_string(SerdReader* me, const uint8_t* utf8)
 	const bool ret = read_turtleDoc(me);
 
 	me->read_buf = NULL;
-	return ret;
+	return ret ? SERD_SUCCESS : SERD_ERR_UNKNOWN;
 }
 
 SERD_API
@@ -1508,7 +1502,7 @@ serd_read_state_get_base_uri(SerdReadState* state,
 }
 
 SERD_API
-bool
+SerdStatus
 serd_read_state_set_base_uri(SerdReadState*  state,
                              const SerdNode* uri_node)
 {
@@ -1522,13 +1516,13 @@ serd_read_state_set_base_uri(SerdReadState*  state,
 		serd_node_free(&state->base_uri_node);
 		state->base_uri_node = base_uri_node;
 		state->base_uri      = base_uri;
-		return true;
+		return SERD_SUCCESS;
 	}
-	return false;
+	return SERD_ERR_BAD_ARG;
 }
 
 SERD_API
-bool
+SerdStatus
 serd_read_state_set_prefix(SerdReadState*  state,
                            const SerdNode* name,
                            const SerdNode* uri_node)
@@ -1536,7 +1530,6 @@ serd_read_state_set_prefix(SerdReadState*  state,
 	if (serd_uri_string_has_scheme(uri_node->buf)) {
 		// Set prefix to absolute URI
 		serd_env_add(state->env, name, uri_node);
-		return true;
 	} else {
 		// Resolve relative URI and create a new node and URI for it
 		SerdURI  abs_uri;
@@ -1544,14 +1537,12 @@ serd_read_state_set_prefix(SerdReadState*  state,
 			uri_node, &state->base_uri, &abs_uri);
 
 		if (!abs_uri_node.buf) {
-			return false;
+			return SERD_ERR_BAD_ARG;
 		}
 
 		// Set prefix to resolved (absolute) URI
 		serd_env_add(state->env, name, &abs_uri_node);
 		serd_node_free(&abs_uri_node);
-		return true;
 	}
-	return false;
+	return SERD_SUCCESS;
 }
-
diff --git a/src/serdi.c b/src/serdi.c
index 0f843344..e3d774ef 100644
--- a/src/serdi.c
+++ b/src/serdi.c
@@ -27,21 +27,21 @@ typedef struct {
 	SerdWriter*    writer;
 } State;
 
-static bool
+static SerdStatus
 event_base(void*           handle,
            const SerdNode* uri_node)
 {
 	State* const state = (State*)handle;
-	if (serd_read_state_set_base_uri(state->read_state, uri_node)) {
+	if (!serd_read_state_set_base_uri(state->read_state, uri_node)) {
 		SerdURI base_uri;
 		serd_read_state_get_base_uri(state->read_state, &base_uri);
 		serd_writer_set_base_uri(state->writer, &base_uri);
-		return true;
+		return SERD_SUCCESS;
 	}
-	return false;
+	return SERD_ERR_UNKNOWN;
 }
 
-static bool
+static SerdStatus
 event_prefix(void*           handle,
              const SerdNode* name,
              const SerdNode* uri_node)
@@ -49,10 +49,10 @@ event_prefix(void*           handle,
 	State* const state = (State*)handle;
 	serd_read_state_set_prefix(state->read_state, name, uri_node);
 	serd_writer_set_prefix(state->writer, name, uri_node);
-	return true;
+	return SERD_SUCCESS;
 }
 
-static bool
+static SerdStatus
 event_statement(void*           handle,
                 const SerdNode* graph,
                 const SerdNode* subject,
@@ -66,7 +66,7 @@ event_statement(void*           handle,
 		graph, subject, predicate, object, object_datatype, object_lang);
 }
 
-static bool
+static SerdStatus
 event_end(void*           handle,
           const SerdNode* node)
 {
@@ -182,7 +182,7 @@ main(int argc, char** argv)
 	SerdURI        base_uri;
 	if (a < argc) {  // Base URI given on command line
 		const uint8_t* const in_base_uri = (const uint8_t*)argv[a++];
-		if (!serd_uri_parse((const uint8_t*)in_base_uri, &base_uri)) {
+		if (serd_uri_parse((const uint8_t*)in_base_uri, &base_uri)) {
 			fprintf(stderr, "Invalid base URI <%s>\n", argv[2]);
 			return 1;
 		}
@@ -193,7 +193,7 @@ main(int argc, char** argv)
 		base_uri_str = (const uint8_t*)"";
 	}
 
-	if (!serd_uri_parse(base_uri_str, &base_uri)) {
+	if (serd_uri_parse(base_uri_str, &base_uri)) {
 		fprintf(stderr, "Invalid base URI <%s>\n", base_uri_str);
 	}
 
@@ -220,7 +220,7 @@ main(int argc, char** argv)
 		SERD_TURTLE, &state,
 		event_base, event_prefix, event_statement, event_end);
 
-	const bool success = (from_file)
+	const SerdStatus status = (from_file)
 		? serd_reader_read_file(reader, in_fd, input)
 		: serd_reader_read_string(reader, input);
 
@@ -235,9 +235,5 @@ main(int argc, char** argv)
 	serd_read_state_free(state.read_state);
 	serd_env_free(state.env);
 
-	if (success) {
-		return 0;
-	}
-
-	return 1;
+	return (status == SERD_SUCCESS) ? 0 : 1;
 }
diff --git a/src/uri.c b/src/uri.c
index 5d2feb74..958ba7da 100644
--- a/src/uri.c
+++ b/src/uri.c
@@ -69,7 +69,7 @@ serd_uri_dump(const SerdURI* uri, FILE* file)
 #endif
 
 SERD_API
-bool
+SerdStatus
 serd_uri_parse(const uint8_t* utf8, SerdURI* uri)
 {
 	*uri = SERD_URI_NULL;
@@ -181,7 +181,7 @@ end:
 	fprintf(stderr, "\n");
 	#endif
 
-	return true;
+	return SERD_SUCCESS;
 }
 
 SERD_API
diff --git a/src/writer.c b/src/writer.c
index 67b69166..6794439a 100644
--- a/src/writer.c
+++ b/src/writer.c
@@ -205,7 +205,7 @@ write_node(SerdWriter*     writer,
 	case SERD_CURIE:
 		switch (writer->syntax) {
 		case SERD_NTRIPLES:
-			if (!serd_env_expand(writer->env, node, &uri_prefix, &uri_suffix)) {
+			if (serd_env_expand(writer->env, node, &uri_prefix, &uri_suffix)) {
 				fprintf(stderr, "Undefined namespace prefix `%s'\n", node->buf);
 				return false;
 			}
@@ -257,7 +257,7 @@ write_node(SerdWriter*     writer,
 		} else if ((writer->style & SERD_STYLE_RESOLVED)
 		           && !serd_uri_string_has_scheme(node->buf)) {
 			SerdURI uri;
-			if (serd_uri_parse(node->buf, &uri)) {
+			if (!serd_uri_parse(node->buf, &uri)) {
 				SerdURI abs_uri;
 				serd_uri_resolve(&uri, &writer->base_uri, &abs_uri);
 				writer->sink("<", 1, writer->stream);
@@ -275,7 +275,7 @@ write_node(SerdWriter*     writer,
 }
 
 SERD_API
-bool
+SerdStatus
 serd_writer_write_statement(SerdWriter*     writer,
                             const SerdNode* graph,
                             const SerdNode* subject,
@@ -292,10 +292,10 @@ serd_writer_write_statement(SerdWriter*     writer,
 		write_node(writer, predicate, NULL, NULL);
 		writer->sink(" ", 1, writer->stream);
 		if (!write_node(writer, object, object_datatype, object_lang)) {
-			return false;
+			return SERD_ERR_UNKNOWN;
 		}
 		writer->sink(" .\n", 3, writer->stream);
-		return true;
+		return SERD_SUCCESS;
 	case SERD_TURTLE:
 		break;
 	}
@@ -362,20 +362,20 @@ serd_writer_write_statement(SerdWriter*     writer,
 	                                   serd_node_copy(predicate) };
 	reset_context(writer);
 	writer->context = new_context;
-	return true;
+	return SERD_SUCCESS;
 }
 
 SERD_API
-bool
+SerdStatus
 serd_writer_end_anon(SerdWriter*     writer,
                      const SerdNode* node)
 {
 	if (writer->syntax == SERD_NTRIPLES) {
-		return true;
+		return SERD_SUCCESS;
 	}
 	if (serd_stack_is_empty(&writer->anon_stack)) {
 		fprintf(stderr, "Unexpected end of anonymous node\n");
-		return false;
+		return SERD_ERR_UNKNOWN;
 	}
 	assert(writer->indent > 0);
 	--writer->indent;
@@ -387,17 +387,18 @@ serd_writer_end_anon(SerdWriter*     writer,
 	if (!writer->context.subject.buf) {  // End of anonymous subject
 		writer->context.subject = serd_node_copy(node);
 	}
-	return true;
+	return SERD_SUCCESS;
 }
 
 SERD_API
-void
+SerdStatus
 serd_writer_finish(SerdWriter* writer)
 {
 	if (writer->context.subject.buf) {
 		writer->sink(" .\n", 3, writer->stream);
 	}
 	reset_context(writer);
+	return SERD_SUCCESS;
 }
 
 SERD_API
@@ -424,7 +425,7 @@ serd_writer_new(SerdSyntax     syntax,
 }
 
 SERD_API
-void
+SerdStatus
 serd_writer_set_base_uri(SerdWriter*    writer,
                          const SerdURI* uri)
 {
@@ -439,10 +440,11 @@ serd_writer_set_base_uri(SerdWriter*    writer,
 		writer->sink("> .\n", 4, writer->stream);
 	}
 	reset_context(writer);
+	return SERD_SUCCESS;
 }
 
 SERD_API
-bool
+SerdStatus
 serd_writer_set_prefix(SerdWriter*     writer,
                        const SerdNode* name,
                        const SerdNode* uri)
@@ -459,7 +461,7 @@ serd_writer_set_prefix(SerdWriter*     writer,
 		writer->sink("> .\n", 4, writer->stream);
 	}
 	reset_context(writer);
-	return true;
+	return SERD_SUCCESS;
 }
 
 SERD_API