X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Flibpspp%2Fllx.h;h=8f01c70f24aa0b8632e2c2f470f8a60e6f53abc3;hb=39df27f80745cf9622ac5e916a098c17961c2585;hp=2aa18e7ba5694bced71cbe32a3feb69700e23f9b;hpb=d0b91eae59319ab2756d0d43b9cb15eb9cd3c234;p=pspp

diff --git a/src/libpspp/llx.h b/src/libpspp/llx.h
index 2aa18e7ba5..8f01c70f24 100644
--- a/src/libpspp/llx.h
+++ b/src/libpspp/llx.h
@@ -1,5 +1,5 @@
 /* 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
@@ -49,7 +49,7 @@
 
 #include <stdbool.h>
 #include <stddef.h>
-#include <libpspp/ll.h>
+#include "libpspp/ll.h"
 
 /* External, circular doubly linked list.
 
@@ -313,5 +313,50 @@ 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 */