Add support for tree structures. Search function with DFS, BFS currently unimplemented. Improve linked list handling; fix bug in circular list detection.

include/akstdlib.h

@@ -5,6 +5,33 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <stdint.h>
+
+typedef struct aksl_ListNode {
+    void *data;
+    struct aksl_ListNode *next;
+    struct aksl_ListNode *prev;
+} aksl_ListNode;
+
+typedef struct aksl_TreeNode {
+    struct aksl_TreeNode *parent;
+    struct aksl_TreeNode *left;
+    struct aksl_TreeNode *right;
+    void *leaf;
+} aksl_TreeNode;
+
+#define AKSL_TREE_SEARCH_BFS           0    /** Breadth-first search mode for tree nodes. Currently unsupported. */
+#define AKSL_TREE_SEARCH_BFS_RIGHT     1    /** Right-hand breadth-first search mode for tree nodes. Currentl unsupported. */
+#define AKSL_TREE_SEARCH_DFS           2    /** Alias for AKSL_TREE_SEARCH_DFS_PREORDER */
+#define AKSL_TREE_SEARCH_DFS_PREORDER  2    /** Depth first pre-order (root, left, right) search mode for tree nodes */
+#define AKSL_TREE_SEARCH_DFS_INORDER   3    /** Depth first in-order (left, root, right) search mode for tree nodes. Currently unsupported. */
+#define AKSL_TREE_SEARCH_DFS_POSTORDER 4    /** Depth first post-order (left, right, root) search mode for tree nodes. Currently unsupported. */
+#define AKSL_TREE_SEARCH_VISIT         5    /** Used when iterating through a tree structure as a control flag: don't traverse the children, just visit the node */
+
+typedef akerr_ErrorContext AKERR_NOIGNORE *(*aksl_ListNodeIterator)(aksl_ListNode *node, void *data);
+typedef akerr_ErrorContext AKERR_NOIGNORE *(*aksl_TreeNodeIterator)(aksl_TreeNode *node, void *data);
+typedef akerr_ErrorContext AKERR_NOIGNORE *(*aksl_AllocFunc)(size_t size, void **dest);
+typedef akerr_ErrorContext AKERR_NOIGNORE *(*aksl_FreeFunc)(void *ptr);
 
 akerr_ErrorContext AKERR_NOIGNORE *aksl_fopen(char *pathname, char *mode, FILE **fp);
 akerr_ErrorContext AKERR_NOIGNORE *aksl_fread(void *ptr, size_t size, size_t nmemb, FILE *stream);
@@ -28,4 +55,12 @@ akerr_ErrorContext AKERR_NOIGNORE *aksl_atof(const char *nptr, double *dest);
 
 akerr_ErrorContext AKERR_NOIGNORE *aksl_realpath(const char *restrict path, char *restrict resolved_path);
 
+// Linked list functions
+akerr_ErrorContext AKERR_NOIGNORE *aksl_list_push(aksl_ListNode *list, aksl_ListNode *obj);
+akerr_ErrorContext AKERR_NOIGNORE *aksl_list_pop(aksl_ListNode *node);
+akerr_ErrorContext AKERR_NOIGNORE *aksl_list_iterate(aksl_ListNode *list, aksl_ListNodeIterator iter, void *data);
+
+// Tree functions
+akerr_ErrorContext AKERR_NOIGNORE *aksl_tree_iterate(aksl_TreeNode *root, aksl_TreeNodeIterator iter, aksl_AllocFunc lalloc, aksl_FreeFunc lfree, uint8_t searchmode, void *data, aksl_ListNode *queue);
+
 #endif

src/stdlib.c

@@ -98,6 +98,7 @@ akerr_ErrorContext AKERR_NOIGNORE *aksl_printf(int *count, const char *restrict
     PREPARE_ERROR(e);
     FAIL_ZERO_RETURN(e, count, AKERR_NULLPOINTER, "count=%p, format=%p", (void *)count, (void *)format);
     FAIL_ZERO_RETURN(e, format, AKERR_NULLPOINTER, "count=%p, format=%p", (void *)count, (void *)format);
+    va_start(args, format);    
     *count = vprintf(format, args);
     FAIL_NONZERO_RETURN(e, (*count == -1), errno, "Short write");
     SUCCEED_RETURN(e);
@@ -111,6 +112,7 @@ akerr_ErrorContext AKERR_NOIGNORE *aksl_fprintf(int *count, FILE *restrict strea
     FAIL_ZERO_RETURN(e, count, AKERR_NULLPOINTER, "count=%p, stream=%p, format=%p", (void *)count, (void *)stream, (void *)format);
     FAIL_ZERO_RETURN(e, stream, AKERR_NULLPOINTER, "count=%p, stream=%p, format=%p", (void *)count, (void *)stream, (void *)format);
     FAIL_ZERO_RETURN(e, format, AKERR_NULLPOINTER, "count=%p, stream=%p, format=%p", (void *)count, (void *)stream, (void *)format);
+    va_start(args, format);
     *count = vfprintf(stream, format, args);
     FAIL_NONZERO_RETURN(e, (*count == -1), errno, "Short write");
     SUCCEED_RETURN(e);
@@ -174,3 +176,146 @@ akerr_ErrorContext AKERR_NOIGNORE *aksl_realpath(const char *restrict path, char
     FAIL_ZERO_RETURN(e, result, errno, "path=%s, dest=%s", path, resolved_path);
     SUCCEED_RETURN(e);
 }
+
+akerr_ErrorContext AKERR_NOIGNORE *aksl_list_push(aksl_ListNode *list, aksl_ListNode *obj)
+{
+    PREPARE_ERROR(e);
+    FAIL_ZERO_RETURN(e, list, AKERR_NULLPOINTER, "list");
+    FAIL_ZERO_RETURN(e, obj, AKERR_NULLPOINTER, "obj");
+    aksl_ListNode *slow = list;
+    aksl_ListNode *fast = list;
+    aksl_ListNode *tail = list;
+    do { 
+	if ( fast != NULL && fast->next != NULL ) {
+	    fast = fast->next->next;
+	}
+	tail = slow;
+	slow = slow->next;
+	if ( fast != NULL && fast == slow) {
+	    FAIL(e, AKERR_CIRCULAR_REFERENCE, "%p", list);
+	}
+    } while ( slow != NULL || (fast != NULL && fast->next != NULL) );
+    tail->next = obj;
+    obj->next = NULL;
+    obj->prev = slow;
+    SUCCEED_RETURN(e);
+}
+
+akerr_ErrorContext AKERR_NOIGNORE *aksl_list_pop(aksl_ListNode *node)
+{
+    PREPARE_ERROR(e);
+    FAIL_ZERO_RETURN(e, node, AKERR_NULLPOINTER, "node");
+    if ( node->prev != NULL ) {
+	node->prev->next = node->next;
+    }
+    if ( node->next != NULL ) {	
+	node->next->prev = node->prev;
+    }
+    node->next = NULL;
+    node->prev = NULL;
+    SUCCEED_RETURN(e);
+}
+
+/**
+ * @brief Iterates over a tree structure in breadth or depth first order, executing a callback function on each node.
+ *
+ * This function recursively calls itself to traverse a binary tree datastructure. 
+ *
+ * @param[in] root The tree structure to search
+ * @param[in] iter An aksl_TreeNodeIterator function which will be called for each node found
+ * @param[in] lalloc An aksl_AllocFunc function which will be used to allocate aksl_ListNode elements for the search, or NULL to use the default allocator (aksl_malloc)
+ * @param[in] lfree An aksl_FreeFunc function which will be used to free the elements procured with lalloc, or NULL to use the default free function (aksl_free)
+ * @param[in] searchmode One of the AKSL_TREE_SEARCH_BFS* defines
+ * @param[in] data Any user data that should be provided when the iterator is called
+ * @param[in] queue The linked list node to use as the head of the queue. The caller should pass NULL here.
+ *
+ * @throws AKERR_NULLPOINTER On null pointer inputs
+ * @return akerr_ErrorContext
+ */
+
+akerr_ErrorContext AKERR_NOIGNORE *aksl_tree_iterate(
+    aksl_TreeNode *root,
+    aksl_TreeNodeIterator iter,
+    aksl_AllocFunc lalloc,
+    aksl_FreeFunc lfree,
+    uint8_t searchmode,
+    void *data,
+    aksl_ListNode *queue)
+{
+    PREPARE_ERROR(e);
+    FAIL_ZERO_RETURN(e, root, AKERR_NULLPOINTER, "root");
+    FAIL_ZERO_RETURN(e, iter, AKERR_NULLPOINTER, "iter");
+    if ( lalloc == NULL ) {
+	lalloc = &aksl_malloc;
+    }
+    if ( lfree == NULL ) {
+	lfree = &aksl_free;
+    }
+    switch ( searchmode ) {
+    case AKSL_TREE_SEARCH_DFS_PREORDER:
+	PASS(e, iter(root, data));
+	if ( root->left != NULL ) {
+	    PASS(e, aksl_tree_iterate(root->left, iter, lalloc, lfree, searchmode, data, NULL));
+	}
+	if ( root-> right != NULL ) {
+	    PASS(e, aksl_tree_iterate(root->right, iter, lalloc, lfree, searchmode, data, NULL));
+	}
+	break;
+    case AKSL_TREE_SEARCH_DFS_POSTORDER:
+	if ( root->left != NULL ) {
+	    PASS(e, aksl_tree_iterate(root->left, iter, lalloc, lfree, searchmode, data, NULL));
+	}
+	if ( root-> right != NULL ) {
+	    PASS(e, aksl_tree_iterate(root->right, iter, lalloc, lfree, searchmode, data, NULL));
+	}
+	PASS(e, iter(root, data));
+	break;
+    case AKSL_TREE_SEARCH_DFS_INORDER:
+	if ( root->left != NULL ) {
+	    PASS(e, aksl_tree_iterate(root->left, iter, lalloc, lfree, searchmode, data, NULL));
+	}
+	PASS(e, iter(root, data));
+	if ( root-> right != NULL ) {
+	    PASS(e, aksl_tree_iterate(root->right, iter, lalloc, lfree, searchmode, data, NULL));
+	}
+	break;
+    case AKSL_TREE_SEARCH_BFS:
+    case AKSL_TREE_SEARCH_BFS_RIGHT:
+	FAIL_RETURN(e, AKERR_NOT_IMPLEMENTED, "Searchmode %d", searchmode);
+	break;
+    }
+    SUCCEED_RETURN(e);
+}
+
+/**
+ * @brief Iterates over a linked list and execute a callback function on each node
+ *
+ * @param[in] list The linked list to iterate
+ * @param[in] iter An aksl_ListNodeIterator function which will be called for each node found
+ * @param[in] data Any user data that should be provided when the iterator is called
+ *
+ * @throws AKERR_NULLPOINTER on null pointer inputs
+ * @throws AKERR_CIRCULAR_REFERENCE when the linked list contains a circular reference
+ * 
+ * @return akerr_ErrorContext
+ */
+akerr_ErrorContext AKERR_NOIGNORE *aksl_list_iterate(aksl_ListNode *list, aksl_ListNodeIterator iter, void *data)
+{
+    PREPARE_ERROR(e);
+    FAIL_ZERO_RETURN(e, list, AKERR_NULLPOINTER, "list");
+    FAIL_ZERO_RETURN(e, iter, AKERR_NULLPOINTER, "iter");
+    aksl_ListNode *slow = list;
+    aksl_ListNode *fast = list;
+    aksl_ListNode *tail = list;
+    do {
+	if ( fast != NULL && fast->next != NULL ) {
+	    fast = fast->next->next;
+	}
+	PASS(e, iter(slow, data));
+	slow = slow->next;
+	if ( fast != NULL && fast == slow) {
+	    FAIL(e, AKERR_CIRCULAR_REFERENCE, "%p", list);
+	}
+    } while ( slow != NULL || (fast != NULL && fast->next != NULL) );
+    SUCCEED_RETURN(e);
+}