+ * - @%% Print a '%' character.
+ * - @%> Print as many white spaces as given in the parameter.
+ * - @%c Print a character
+ * - @%s A string.
+ * - @%p A pointer.
+ * - @%d A decimal integer.
+ * - @%x A hexadecimal integer.
+ * - @%o An octal integer.
+ * - @%I An ident.
+ * - @%t A type name.
+ * - @%e An entity name.
+ * - @%E An entity ld name.
+ * - @%T A tarval.
+ * - @%n A full description of a node.
+ * - @%O The opcode name of an ir node.
+ * - @%N The node number of an ir node.
+ * - @%m The mode name of an ir mode.
+ * - @%B The block node number of the nodes block.
+ * - @%b A bitset.
+ * - @%= A pnc value
+ * - @%G A debug info (if available)
+ * - @%P A compound graph path
+ *
+ * Each of these can be prepend by a '+' which means, that the given
+ * pointer is a collection of items specified by the format. In this
+ * case you also have to pass an iterator interface to ir_printf()
+ * suitable for the instance of the collection. So, imagine you have a
+ * @c pset of ir_nodes and want to dump it, you write:
+ * @code
+ * pset *nodes;
+ * ...
+ * ir_printf("Some nodes: %*n\n", it_pset, nodes);
+ * @endcode
+ * The @c it_pset is an iterator interface (of type
+ * @c iterator_t that allows the dumper to traverse the set.
+ *
+ * As special case when working with collections, you can also give a
+ * callback function which will be invoked on each element in the
+ * collection. It gets the appender (the thing where the textual
+ * representation of the element is written to) and its parameters
+ * passed by the dumping function. Suppose you have your own data type
+ * @c xyz_t and want to dump a pset of it, you have:
+ * @code
+ * void xyz_dump(const appender_t *app, void *object, size_t limit,
+ * const void *arg)
+ * {
+ * const xyz_t *xyz = arg;
+ * app->append_str(object, limit, xyz->name);
+ * }
+ * ...
+ * pset *xyzs;