ucx: comparison src/cx/iterator.h

-:6c81ee4f11ad
+:ac5e7f789048
 #define UCX_ITERATOR_H
 #include "common.h"
 /**
-* Internal iterator struct - use CxIterator.
+* The base of mutating and non-mutating iterators.
 */
-struct cx_iterator_s {
+struct cx_iterator_base_s {
 /**
 * True iff the iterator points to valid data.
 */
 __attribute__ ((__nonnull__))
-bool (*valid)(struct cx_iterator_s const *);
+bool (*valid)(void const *);
 /**
 * Returns a pointer to the current element.
 */
 __attribute__ ((__nonnull__))
-void *(*current)(struct cx_iterator_s const *);
+void *(*current)(void const *);
 /**
 * Advances the iterator.
 */
 __attribute__ ((__nonnull__))
-void (*next)(struct cx_iterator_s *);
+void (*next)(void *);
+/**
+* Flag current element for removal, if possible.
+*/
+__attribute__ ((__nonnull__))
+bool (*flag_removal)(void *);
+/**
+* Indicates whether this iterator is muting.
+*/
+bool mutating;
+/**
+* Internal flag for removing the current element when advancing.
+*/
+bool remove;
+};
+/**
+* Internal iterator struct - use CxMutIterator.
+*/
+struct cx_mut_iterator_s {
+/**
+* The base properties of this iterator.
+*/
+struct cx_iterator_base_s base;
 /**
 * Handle for the current element, if required.
 */
 void *elem_handle;
 */
 struct {
 /**
 * A pointer to the key.
 */
-void *key;
+void const *key;
 /**
 * A pointer to the value.
 */
 void *value;
 } kv_data;
 /**
 * If the iterator is position-aware, contains the index of the element in the underlying collection.
 * Otherwise, this field is usually uninitialized.
 */
 size_t index;
+};
-/**
-* Users may set this to true, if the current element shall be removed from the underlying collection
+/**
-* when the iterator advances.
+* Mutating iterator value type.
-* Has no effect on iterators that are not based on a collection.
+*
-*/
+* An iterator points to a certain element in an (possibly unbounded) chain of elements.
-bool remove;
+* Iterators that are based on collections (which have a defined "first" element), are supposed
+* to be "position-aware", which means that they keep track of the current index within the collection.
+*
+* @note Objects that are pointed to by an iterator are mutable through that iterator. However, if the
+* iterator is based on a collection and the underlying collection is mutated by other means than this iterator
+* (e.g. elements added or removed), the iterator becomes invalid (regardless of what cxIteratorValid() returns)
+* and MUST be re-obtained from the collection.
+*
+* @see CxIterator
+*/
+typedef struct cx_mut_iterator_s CxMutIterator;
+/**
+* Internal iterator struct - use CxIterator.
+*/
+struct cx_iterator_s {
+/**
+* The base properties of this iterator.
+*/
+struct cx_iterator_base_s base;
+/**
+* Handle for the current element, if required.
+*/
+void *elem_handle;
+/**
+* Handle for the source collection, if any.
+*/
+void const *src_handle;
+/**
+* Field for storing a key-value pair.
+* May be used by iterators that iterate over k/v-collections.
+*/
+struct {
+/**
+* A pointer to the key.
+*/
+void const *key;
+/**
+* A pointer to the value.
+*/
+void *value;
+} kv_data;
+/**
+* Field for storing a slot number.
+* May be used by iterators that iterate over multi-bucket collections.
+*/
+size_t slot;
+/**
+* If the iterator is position-aware, contains the index of the element in the underlying collection.
+* Otherwise, this field is usually uninitialized.
+*/
+size_t index;
 };
 /**
 * Iterator value type.
 * An iterator points to a certain element in an (possibly unbounded) chain of elements.
 * Iterators that are based on collections (which have a defined "first" element), are supposed
 * to be "position-aware", which means that they keep track of the current index within the collection.
 *
-* @note Objects that are pointed to by an iterator are mutable through that iterator. However, if the
+* @note Objects that are pointed to by an iterator are always mutable through that iterator. However,
-* iterator is based on a collection and the underlying collection is mutated (elements added or removed),
+* this iterator cannot mutate the collection itself (add or remove elements) and any mutation of the
-* the iterator becomes invalid (regardless of what cxIteratorValid() returns) and MUST be re-obtained
+* collection by other means make this iterator invalid (regardless of what cxIteratorValid() returns).
-* from the collection.
+*
+* @see CxMutIterator
 */
 typedef struct cx_iterator_s CxIterator;
 /**
 * Checks if the iterator points to valid data.
 *
 * This is especially false for past-the-end iterators.
 *
-* @param iter a pointer to the iterator
+* @param iter the iterator
 * @return true iff the iterator points to valid data
 */
-__attribute__ ((__nonnull__))
+#define cxIteratorValid(iter) (iter).base.valid(&(iter))
-static inline bool cxIteratorValid(CxIterator const *iter) {
-return iter->valid(iter);
-}
 /**
 * Returns a pointer to the current element.
 *
 * The behavior is undefined if this iterator is invalid.
 *
-* @param iter a pointer to the iterator
+* @param iter the iterator
 * @return a pointer to the current element
 */
-__attribute__ ((__nonnull__))
+#define cxIteratorCurrent(iter) (iter).base.current(&iter)
-static inline void *cxIteratorCurrent(CxIterator const *iter) {
-return iter->current(iter);
-}
 /**
 * Advances the iterator to the next element.
 *
-* @param iter a pointer to the iterator
+* @param iter the iterator
 */
-__attribute__ ((__nonnull__))
+#define cxIteratorNext(iter) (iter).base.next(&iter)
-static inline void cxIteratorNext(CxIterator *iter) {
-iter->next(iter);
+/**
-}
+* Flags the current element for removal.
+*
+* @param iter the iterator
+* @return false if this iterator cannot remove the element
+*/
+#define cxIteratorFlagRemoval(iter) (iter).base.flag_removal(&iter)
 /**
 * Loops over an iterator.
 * @param type the type of the elements
 * @param elem the name of the iteration variable
 * @param iter the iterator
 */
 #define cx_foreach(type, elem, iter) \
-for (type elem; cxIteratorValid(&iter) && (elem = (type)cxIteratorCurrent(&iter)) != NULL ; cxIteratorNext(&iter)) // NOLINT(bugprone-macro-parentheses)
+for (type elem; cxIteratorValid(iter) && (elem = (type)cxIteratorCurrent(iter)) != NULL ; cxIteratorNext(iter))
 #endif // UCX_ITERATOR_H

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comparison: src/cx/iterator.h

src/cx/iterator.h