/* PSPP - a program for statistical analysis.
- Copyright (C) 2006 Free Software Foundation, Inc.
+ 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
#include <stdbool.h>
#include <stddef.h>
-#include <libpspp/ll.h>
+#include "libpspp/ll.h"
/* External, circular doubly linked list.
{
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 */