-/*
- * Copyright (c) 2016, Olivier MATZ <zer0@droids-corp.org>
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
- *
- * * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * * Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- * * Neither the name of the University of California, Berkeley nor the
- * names of its contributors may be used to endorse or promote products
- * derived from this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND ANY
- * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
- * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
- * DISCLAIMED. IN NO EVENT SHALL THE REGENTS AND CONTRIBUTORS BE LIABLE FOR ANY
- * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
- * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
- * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
- * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
- * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright 2016, Olivier MATZ <zer0@droids-corp.org>
*/
-#ifndef ECOLI_NODE_BYPASS_
-#define ECOLI_NODE_BYPASS_
+#ifndef ECOLI_NODE_WEAKREF_
+#define ECOLI_NODE_WEAKREF_
#include <ecoli_node.h>
-/* a node that just behaves like its child and that does not free
- * its child when freed.
+/* A node that just behaves like its child and that does not free
+ * its child when freed. **The child has to be freed manually**.
*
* useful to create cyclic graphs of nodes:
* creating a loop (with clones) result in something that is not
* freeable, due to reference counters
*
* Example:
+ * expr = or()
* val = int(0, 10)
* op = str("!")
- * expr = or()
- * seq = seq(clone(op), clone(expr))
- * expr.add(clone(seq))
- * expr.add(clone(val))
- * free(val)
- * free(op)
- * free(seq)
+ * seq = seq(op, clone(expr))
+ * expr.add(seq)
+ * expr.add(val)
+ * free(expr) // just decrease ref
*
* FAIL: expr cannot be freed due to cyclic refs
* The references are like this:
* val
* ^
* |
- * $user ---> expr ---> seq ---> op
+ * $user ~ ~ ~ > expr ---> seq ---> op
* <---
*
* It is solved with:
+ * expr = or()
* val = int(0, 10)
* op = str("!")
- * expr = or()
* weak = weak(expr)
- * seq = seq(clone(op), clone(weak))
- * expr.add(clone(seq))
- * expr.add(clone(val))
- * free(val)
- * free(op)
- * free(weak)
- * free(seq)
+ * seq = seq(op, weak)
+ * expr.add(op)
+ * expr.add(val)
*
*
* val
* ^
* |
- * $user ---> expr ---------------> seq ---> op
+ * $user ~ ~ ~ > expr ---------------> seq ---> op
* <- - - weak <---
*
* The node expr can be freed.
/* on error, child is *not* freed */
struct ec_node *ec_node_weakref(const char *id, struct ec_node *child);
-struct ec_node *ec_node_weakref_empty(const char *id);
-
/* on error, child is *not* freed */
int ec_node_weakref_set(struct ec_node *node, struct ec_node *child);