WIP: expander

1 files changed, 91 insertions, 0 deletions

diff --git a/src/expander.c b/src/expander.c
new file mode 100644
index 00000000..4a49f77c
--- /dev/null
+++ b/src/expander.c
@@ -0,0 +1,91 @@
+/*
+  Copyright 2019-2020 David Robillard <http://drobilla.net>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#include "sink.h"
+#include "statement.h"
+
+#include "serd/serd.h"
+
+#include <stdbool.h>
+#include <stdlib.h>
+
+#include <stdio.h>
+
+typedef struct
+{
+	const SerdSink* target;
+} SerdExpanderData;
+
+static SerdStatus
+serd_expander_on_event(void* handle, const SerdEvent* event)
+{
+	const SerdExpanderData* const data = (SerdExpanderData*)handle;
+
+	if (event->type != SERD_STATEMENT) {
+		return serd_sink_write_event(data->target, event);
+	}
+
+	const SerdEnv* const       env       = serd_sink_get_env(data->target);
+	const SerdStatement* const statement = event->statement.statement;
+
+	SerdNode* xs = serd_env_expand(env, serd_statement_get_subject(statement));
+	SerdNode* xp = serd_env_expand(env, serd_statement_get_predicate(statement));
+	SerdNode* xo = serd_env_expand(env, serd_statement_get_object(statement));
+	SerdNode* xg = serd_env_expand(env, serd_statement_get_graph(statement));
+
+	const SerdNode* const s = xs ? xs : serd_statement_get_subject(statement);
+	const SerdNode* const p = xp ? xp : serd_statement_get_predicate(statement);
+	const SerdNode* const o = xo ? xo : serd_statement_get_object(statement);
+	const SerdNode* const g = xg ? xg : serd_statement_get_graph(statement);
+	/* if (!xs || !p || !o || !g) { */
+	/* 	fprintf(stderr, "invalid\n"); */
+	/* 	return SERD_ERR_INVALID; */
+	/* } */
+
+	const SerdStatement expanded       = {{s, p, o, g}, statement->cursor};
+	SerdEvent           expanded_event = {SERD_STATEMENT};
+
+	expanded_event.statement.flags     = event->statement.flags;
+	expanded_event.statement.statement = &expanded;
+
+	SerdStatus st = serd_sink_write_event(data->target, &expanded_event);
+
+	serd_node_free(xg);
+	serd_node_free(xo);
+	serd_node_free(xp);
+	serd_node_free(xs);
+
+	return st;
+}
+
+SerdSink*
+serd_expander_new(const SerdSink* const target)
+{
+	if (!serd_sink_get_env(target)) {
+		return NULL;
+	}
+
+	SerdExpanderData* data =
+	    (SerdExpanderData*)calloc(1, sizeof(SerdExpanderData));
+
+	data->target = target;
+
+	SerdSink* const sink = serd_sink_new(data, free);
+
+	serd_sink_set_event_func(sink, serd_expander_on_event);
+
+	return sink;
+}