Add support for writing terse collections

1 files changed, 23 insertions, 12 deletions

diff --git a/src/writer.c b/src/writer.c
index 15b527a2..037454eb 100644
--- a/src/writer.c
+++ b/src/writer.c
@@ -61,8 +61,11 @@ typedef enum {
 	SEP_ANON_S_P,    ///< Between start of anonymous node and predicate
 	SEP_ANON_END,    ///< End of anonymous node (']')
 	SEP_LIST_BEGIN,  ///< Start of list ('(')
-	SEP_LIST_SEP,    ///< List separator (whitespace)
+	SEP_LIST_SEP,    ///< List separator (newline)
 	SEP_LIST_END,    ///< End of list (')')
+	SEP_TLIST_BEGIN, ///< Start of terse list ('(')
+	SEP_TLIST_SEP,   ///< Terse list separator (space)
+	SEP_TLIST_END,   ///< End of terse list (')')
 	SEP_GRAPH_BEGIN, ///< Start of graph ('{')
 	SEP_GRAPH_END,   ///< End of graph ('}')
 } Sep;
@@ -89,12 +92,15 @@ static const SepRule rules[] = {
 	{",",   1, +0, SEP_ALL,      SEP_NONE, ~(M(SEP_ANON_END) | M(SEP_LIST_END))},
 	{"",    0, +1, SEP_NONE,     SEP_NONE, SEP_ALL},
 	{" ",   1, +0, SEP_NONE,     SEP_NONE, SEP_NONE},
-	{"[",   1, +1, M(SEP_END_O), SEP_NONE, SEP_NONE},
+	{"[",   1, +1, M(SEP_END_O), M(SEP_TLIST_BEGIN)|M(SEP_TLIST_SEP), SEP_NONE},
 	{"",    0, +0, SEP_NONE,     SEP_ALL, SEP_NONE},
 	{"]",   1, -1, SEP_NONE,     ~M(SEP_ANON_BEGIN), SEP_NONE},
 	{"(",   1, +1, M(SEP_END_O), SEP_NONE, SEP_ALL},
 	{"",    0, +0, SEP_NONE,     SEP_ALL, SEP_NONE},
 	{")",   1, -1, SEP_NONE,     SEP_ALL, SEP_NONE},
+	{"(",   1, +1, SEP_NONE,     SEP_NONE, SEP_NONE},
+	{"",    0, +0, SEP_ALL,      SEP_NONE, SEP_NONE},
+	{")",   1, -1, SEP_NONE,     SEP_NONE, SEP_NONE},
 	{"{",   1, +1, SEP_ALL,      SEP_NONE, SEP_NONE},
 	{"}",   1, -1, SEP_NONE,     SEP_NONE, SEP_ALL},
 	{"<",   1, +0, SEP_NONE,     SEP_NONE, SEP_NONE},
@@ -378,9 +384,9 @@ uri_sink(const void* buf, size_t size, size_t nmemb, void* stream)
 }
 
 static void
-write_newline(SerdWriter* writer)
+write_newline(SerdWriter* writer, bool terse)
 {
-	if (writer->flags & SERD_WRITE_TERSE) {
+	if (terse || (writer->flags & SERD_WRITE_TERSE)) {
 		sink(" ", 1, writer);
 	} else {
 		sink("\n", 1, writer);
@@ -394,16 +400,19 @@ static void
 write_top_level_sep(SerdWriter* writer)
 {
 	if (!writer->empty && !(writer->flags & SERD_WRITE_TERSE)) {
-		write_newline(writer);
+		write_newline(writer, false);
 	}
 }
 
 static bool
 write_sep(SerdWriter* writer, const SerdStatementFlags flags, Sep sep)
 {
-	(void)flags;
-
-	const SepRule* rule = &rules[sep];
+	const SepRule* rule  = &rules[sep];
+	const bool     terse = (((flags & SERD_TERSE_S) && (flags & SERD_LIST_S)) ||
+	                        ((flags & SERD_TERSE_O) && (flags & SERD_LIST_O)));
+	if (terse && sep >= SEP_LIST_BEGIN && sep <= SEP_LIST_END) {
+		sep = (Sep)((int)sep + 3); // Switch to corresponding terse separator
+	}
 
 	// Adjust indent, but tolerate if it would become negative
 	writer->indent =
@@ -413,7 +422,7 @@ write_sep(SerdWriter* writer, const SerdStatementFlags flags, Sep sep)
 
 	// Write newline or space before separator if necessary
 	if (rule->pre_line_after & (1u << writer->last_sep)) {
-		write_newline(writer);
+		write_newline(writer, terse);
 	} else if (rule->pre_space_after & (1u << writer->last_sep)) {
 		sink(" ", 1, writer);
 	}
@@ -423,7 +432,7 @@ write_sep(SerdWriter* writer, const SerdStatementFlags flags, Sep sep)
 
 	// Write newline after separator if necessary
 	if (rule->post_line_after & (1u << writer->last_sep)) {
-		write_newline(writer);
+		write_newline(writer, terse);
 	}
 
 	writer->last_sep = sep;
@@ -758,8 +767,10 @@ serd_writer_write_statement(SerdWriter*          writer,
 	const SerdNode* const graph     = serd_statement_get_graph(statement);
 
 	if (!is_resource(subject) || !is_resource(predicate) || !object ||
-	    ((flags & SERD_ANON_S) && (flags & SERD_LIST_S)) ||
-	    ((flags & SERD_ANON_O) && (flags & SERD_LIST_O))) {
+	    ((flags & SERD_ANON_S) && (flags & SERD_LIST_S)) ||  // Nonsense
+	    ((flags & SERD_ANON_O) && (flags & SERD_LIST_O)) ||  // Nonsense
+	    ((flags & SERD_ANON_S) && (flags & SERD_TERSE_S)) || // Unsupported
+	    ((flags & SERD_ANON_O) && (flags & SERD_TERSE_O))) { // Unsupported
 		return SERD_ERR_BAD_ARG;
 	}