-/* PSPP - computes sample statistics.
- Copyright (C) 2006 Free Software Foundation, Inc.
- Written by Ben Pfaff <blp@gnu.org>.
+/* PSPP - a program for statistical analysis.
+ Copyright (C) 2006, 2011 Free Software Foundation, Inc.
- This program is free software; you can redistribute it and/or
- modify it under the terms of the GNU General Public License as
- published by the Free Software Foundation; either version 2 of the
- License, or (at your option) any later version.
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
- This program 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
- General Public License for more details.
+ This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
- 02110-1301, USA. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
/* Circular doubly linked lists.
#include <stdbool.h>
#include <stddef.h>
-#include <libpspp/ll.h>
+#include "libpspp/ll.h"
/* External, circular doubly linked list.
Here's an example of iteration from head to tail:
struct llx *llx;
- for (llx = llx_head (&list); llx != llx_null (&list);
+ for (llx = llx_head (&list); llx != llx_null (&list);
llx = llx_next (llx))
{
struct foo *foo = llx_data (llx);
struct ll_list ll_list; /* The list. */
};
+/* Suitable for use as the initializer for a `struct llx_list'
+ named LIST. Typical usage:
+ struct llx_list list = LLX_INITIALIZER (list);
+ LLX_INITIALIZER() is an alternative to llx_init(). */
+#define LLX_INITIALIZER(LIST) { LL_INITIALIZER ((LIST).ll_list) }
+
/* Memory manager. */
-struct llx_manager
+struct llx_manager
{
/* Allocates and returns memory for a new struct llx.
If space is unavailable, returns a null pointer. */
const struct llx_manager *);
/* Non-mutating algorithms. */
+struct llx *llx_find (const struct llx *r0, const struct llx *r1,
+ const void *target);
struct llx *llx_find_equal (const struct llx *r0, const struct llx *r1,
const void *target,
llx_compare_func *, void *aux);
struct llx *llx_min (const struct llx *r0, const struct llx *r1,
llx_compare_func *, void *aux);
int llx_lexicographical_compare_3way (const struct llx *a0,
- const struct llx *a1,
+ const struct llx *a1,
const struct llx *b0,
- const struct llx *b1,
+ const struct llx *b1,
llx_compare_func *, void *aux);
/* Mutating algorithms. */
/* Returns the llx within which LL is embedded. */
static struct llx *
-llx_from_ll (struct ll *ll)
+llx_from_ll (struct ll *ll)
{
return ll_data (ll, struct llx, ll);
}
/* Initializes LIST as an empty list. */
static inline void
-llx_init (struct llx_list *list)
+llx_init (struct llx_list *list)
{
ll_init (&list->ll_list);
}
false if LIST is not empty (has at least one other node).
Executes in O(1) time. */
static inline bool
-llx_is_empty (const struct llx_list *list)
+llx_is_empty (const struct llx_list *list)
{
return ll_is_empty (&list->ll_list);
}
/* Returns the first node in LIST,
or the null node if LIST is empty. */
static inline struct llx *
-llx_head (const struct llx_list *list)
+llx_head (const struct llx_list *list)
{
return llx_from_ll (ll_head (&list->ll_list));
}
/* Returns the last node in LIST,
or the null node if LIST is empty. */
static inline struct llx *
-llx_tail (const struct llx_list *list)
+llx_tail (const struct llx_list *list)
{
return llx_from_ll (ll_tail (&list->ll_list));
}
/* Returns LIST's null node. */
static inline struct llx *
-llx_null (const struct llx_list *list)
+llx_null (const struct llx_list *list)
{
return llx_from_ll (ll_null (&list->ll_list));
}
or the null node if LLX is at the end of its list.
(In an empty list, the null node follows itself.) */
static inline struct llx *
-llx_next (const struct llx *llx)
+llx_next (const struct llx *llx)
{
return llx_from_ll (ll_next (&llx->ll));
}
/* Returns the data in node LLX. */
static inline void *
-llx_data (const struct llx *llx)
+llx_data (const struct llx *llx)
{
return llx->data;
}
+/* Iteration helper macros. */
+
+/* Sets "struct llx *" NODE to each object in LIST in turn, in forward or
+ reverse order.
+
+ Behavior is undefined if NODE is removed from the list between
+ loop iterations. */
+#define llx_for_each(NODE, LIST) \
+ for ((NODE) = llx_head (LIST); \
+ (NODE) != llx_null (LIST); \
+ (NODE) = llx_next (NODE))
+#define llx_for_each_reverse(NODE, LIST) \
+ for ((NODE) = llx_tail (LIST); \
+ (NODE) != llx_null (LIST); \
+ (NODE) = llx_prev (NODE))
+
+/* Sets "struct llx *" NODE to each object in LIST in turn, in forward or
+ reverse order. NEXT (or PREV) must be another "struct llx *" variable.
+
+ Behavior is well-defined even if NODE is removed from the list between
+ iterations. */
+#define llx_for_each_safe(NODE, NEXT, LIST) \
+ for (NODE = llx_head (LIST); \
+ ((NODE) != llx_null (LIST) \
+ ? ((NEXT) = llx_next (NODE), 1) \
+ : 0); \
+ (NODE) = (NEXT))
+#define llx_for_each_reverse_safe(NODE, PREV, LIST) \
+ for (NODE = llx_tail (LIST); \
+ ((NODE) != llx_null (LIST) \
+ ? ((PREV) = llx_prev (NODE), 1) \
+ : 0); \
+ (NODE) = (PREV))
+
+/* Sets DATA to the data from each object in LIST in turn, in forward or
+ reverse order. Each object is removed from LIST before its loop
+ iteration. */
+#define llx_for_each_preremove(DATA, LIST, MANAGER) \
+ while (!llx_is_empty (LIST) \
+ ? ((DATA) = llx_pop_head (LIST, MANAGER), 1) \
+ : 0)
+#define llx_for_each_reverse_preremove(DATA, LIST, MANAGER) \
+ while (!llx_is_empty (LIST) \
+ ? ((DATA) = llx_pop_tail (LIST, MANAGER), 1) \
+ : 0)
#endif /* llx.h */
projects / pspp / blobdiff