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+/* A set of expandable list utilities, implimented as macros. */
+/* Copyright 2006 Graeme W. Gill */
+
+#ifndef _XLIST_H_
+
+/* An expanding list structure */
+#define XLIST(objtype, name) \
+struct { \
+ int no; /* Number of items in list */ \
+ int _no; /* Allocated size of list */ \
+ int objsz; /* Size of object */ \
+ objtype *list; /* list */ \
+} name;
+
+/* Initialize the list */
+#define XLIST_INIT(objtype, xlp) \
+ ((xlp)->no = (xlp)->_no = 0, \
+ (xlp)->objsz = sizeof(objtype), \
+ (xlp)->list = NULL \
+ )
+
+/* test if the list is empty */
+#define IS_XLIST_EMPTY(xlp) \
+ ((xlp)->no == 0)
+
+/* Return the number of items in the list */
+#define XLIST_NO(xlp) \
+ ((xlp)->no)
+
+/* Return the n'th item in the list */
+#define XLIST_ITEM(xlp, n) \
+ ((xlp)->list[n])
+
+/* Add an item to the end of a list */
+/* We call error() if malloc failes */
+#define XLIST_ADD(xlp, obj) \
+ { \
+ if ((xlp)->_no <= 0) { \
+ (xlp)->_no = 10; \
+ if (((xlp)->list = malloc((xlp)->objsz * (xlp)->_no)) == NULL) \
+ error("XLIST malloc failed on %d items of size %d", (xlp)->objsz, (xlp)->_no); \
+ } else if ((xlp)->_no <= (xlp)->no) { \
+ (xlp)->_no *= 2; \
+ if (((xlp)->list = realloc((xlp)->list, (xlp)->objsz * (xlp)->_no)) == NULL) \
+ error("XLIST realloc failed on %d items of size %d", (xlp)->objsz, (xlp)->_no); \
+ } \
+ (xlp)->list[(xlp)->no++] = (obj); \
+ }
+
+/* Free up the list */
+#define XLIST_FREE(xlp) \
+ { if ((xlp)->_no > 0) free((xlp)->list); }
+
+#define _XLIST_H_
+#endif /* _XLIST_H_ */
+