Rework character reading functions to support reading multi-byte characters (take a string dest parameter instead of returning uchar).

Escape ntriples output.
Pass all good read tests with output verification.


git-svn-id: http://svn.drobilla.net/serd/trunk@8 490d8e77-9747-427b-9fa3-0b8f29cee8a0

1 files changed, 170 insertions, 0 deletions

diff --git a/src/write.c b/src/write.c
new file mode 100644
index 00000000..c2b92d78
--- /dev/null
+++ b/src/write.c
@@ -0,0 +1,170 @@
+/* Serd, an RDF serialisation library.
+ * Copyright 2011 David Robillard <d@drobilla.net>
+ * 
+ * Serd is free software: you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Serd is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
+ * License for details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <assert.h>
+#include <stdlib.h>
+
+#include "serd/serd.h"
+
+static size_t
+file_sink(const uint8_t* buf, size_t len, void* stream)
+{
+	FILE* file = (FILE*)stream;
+	return fwrite(buf, 1, len, file);
+}
+
+static inline bool
+serd_write_uri(FILE* file, const SerdURI* uri)
+{
+	return serd_uri_serialise(uri, file_sink, file);
+}
+
+static bool
+serd_write_ascii(const uint8_t* utf8, size_t n_bytes, FILE* out_fd, const uint8_t esc)
+{
+	for (size_t i = 0; i < n_bytes;) {
+		uint8_t in = utf8[i++];
+		switch (in) {
+		case '\\': fwrite("\\\\", 1, 2, out_fd); continue;
+		case '\n': fwrite("\\n",  1, 2, out_fd); continue;
+		case '\r': fwrite("\\r",  1, 2, out_fd); continue;
+		case '\t': fwrite("\\t",  1, 2, out_fd); continue;
+		case '"':  if (esc == '"') { fwrite("\\\"", 1, 2, out_fd); continue; }
+		default: break;
+		}
+
+		if (in == esc) {
+			fprintf(out_fd, "\\u%04X", esc);
+			continue;
+		}
+
+		uint32_t c    = 0;
+		size_t   size = 0;
+		if ((in & 0x80) == 0) {  // Starts with `0'
+			size = 1;
+			c = in & 0x7F;
+			if ((in >= 0x20) && (in <= 0x7E)) {  // Printable ASCII
+				fwrite(&in, 1, 1, out_fd);
+				continue;
+			}
+		} else if ((in & 0xE0) == 0xC0) {  // Starts with `110'
+			size = 2;
+			c = in & 0x1F;
+		} else if ((in & 0xF0) == 0xE0) {  // Starts with `1110'
+			size = 3;
+			c = in & 0x0F;
+		} else if ((in & 0xF8) == 0xF0) {  // Starts with `11110'
+			size = 4;
+			c = in & 0x07;
+		} else if ((in & 0xFC) == 0xF8) {  // Starts with `111110'
+			size = 5;
+			c = in & 0x03;
+		} else if ((in & 0xFE) == 0xFC) {  // Starts with `1111110'
+			size = 6;
+			c = in & 0x01;
+		} else {
+			fprintf(stderr, "invalid UTF-8 at offset %zu: %X\n", i, in);
+			return false;
+		}
+
+#define READ_BYTE() do { \
+			assert(i < n_bytes); \
+			in = utf8[i++] & 0x3f; \
+			c <<= 6; \
+			c |= in; \
+		} while (0)
+
+		switch (size) {
+		case 6: READ_BYTE();
+		case 5: READ_BYTE();
+		case 4: READ_BYTE();
+		case 3: READ_BYTE();
+		case 2: READ_BYTE();
+		}
+
+		if (c < 0xFFFF) {
+			fprintf(out_fd, "\\u%04X", c);
+		} else {
+			fprintf(out_fd, "\\U%08X", c);
+		}
+	}
+	return true;
+}
+
+SERD_API
+bool
+serd_write_node(FILE*             fd,
+                const SerdURI*    base_uri,
+                SerdNamespaces    ns,
+                SerdNodeType      type,
+                const SerdString* str,
+                const SerdString* datatype,
+                const SerdString* lang)
+{
+	SerdRange uri_prefix;
+	SerdRange uri_suffix;
+	switch (type) {
+	case BLANK:
+		fwrite("_:", 1, 2, fd);
+		fwrite(str->buf, 1, str->n_bytes - 1, fd);
+		break;
+	case QNAME:
+		if (!serd_namespaces_expand(ns, str, &uri_prefix, &uri_suffix)) {
+			fprintf(stderr, "error: undefined namespace prefix `%s'\n", str->buf);
+			return false;
+		}
+		fwrite("<", 1, 1, fd);
+		serd_write_ascii(uri_prefix.buf, uri_prefix.len, fd, '>');
+		serd_write_ascii(uri_suffix.buf, uri_suffix.len, fd, '>');
+		fwrite(">", 1, 1, fd);
+		break;
+	case URI:
+		if (serd_uri_string_is_relative(str->buf)) {
+			SerdURI uri;
+			if (serd_uri_parse(str->buf, &uri)) {
+				SerdURI abs_uri;
+				if (serd_uri_resolve(&uri, base_uri, &abs_uri)) {
+					fwrite("<", 1, 1, fd);
+					serd_write_uri(fd, &abs_uri);
+					fwrite(">", 1, 1, fd);
+					return true;
+				}
+			}
+		} else {
+			fwrite("<", 1, 1, fd);
+			serd_write_ascii(str->buf, str->n_bytes - 1, fd, '>');
+			fwrite(">", 1, 1, fd);
+			return true;
+		}
+		return false;
+	case LITERAL:
+		fwrite("\"", 1, 1, fd);
+		serd_write_ascii(str->buf, str->n_bytes - 1, fd, '"');
+		fwrite("\"", 1, 1, fd);
+		if (lang) {
+			fwrite("@\"", 1, 2, fd);
+			fwrite(lang->buf, 1, lang->n_bytes - 1, fd);
+			fwrite("\"", 1, 1, fd);
+		} else if (datatype) {
+			fwrite("^^", 1, 2, fd);
+			serd_write_node(fd, base_uri, ns, URI, datatype, NULL, NULL);
+		}
+		break;
+	}
+	return true;
+}
+