N-ary Trees

N-ary Trees — trees of data with any number of branches

Synopsis

#include <glib.h>

struct              GNode;
GNode *             g_node_new                          (gpointer data);
GNode *             g_node_copy                         (GNode *node);
gpointer            (*GCopyFunc)                        (gconstpointer src,
                                                         gpointer data);
GNode *             g_node_copy_deep                    (GNode *node,
                                                         GCopyFunc copy_func,
                                                         gpointer data);

GNode *             g_node_insert                       (GNode *parent,
                                                         gint position,
                                                         GNode *node);
GNode *             g_node_insert_before                (GNode *parent,
                                                         GNode *sibling,
                                                         GNode *node);
GNode *             g_node_insert_after                 (GNode *parent,
                                                         GNode *sibling,
                                                         GNode *node);
#define             g_node_append                       (parent,
                                                         node)
GNode *             g_node_prepend                      (GNode *parent,
                                                         GNode *node);

#define             g_node_insert_data                  (parent,
                                                         position,
                                                         data)
#define             g_node_insert_data_after            (parent,
                                                         sibling,
                                                         data)
#define             g_node_insert_data_before           (parent,
                                                         sibling,
                                                         data)
#define             g_node_append_data                  (parent,
                                                         data)
#define             g_node_prepend_data                 (parent,
                                                         data)

void                g_node_reverse_children             (GNode *node);
void                g_node_traverse                     (GNode *root,
                                                         GTraverseType order,
                                                         GTraverseFlags flags,
                                                         gint max_depth,
                                                         GNodeTraverseFunc func,
                                                         gpointer data);
enum                GTraverseFlags;
gboolean            (*GNodeTraverseFunc)                (GNode *node,
                                                         gpointer data);
void                g_node_children_foreach             (GNode *node,
                                                         GTraverseFlags flags,
                                                         GNodeForeachFunc func,
                                                         gpointer data);
void                (*GNodeForeachFunc)                 (GNode *node,
                                                         gpointer data);

GNode *             g_node_get_root                     (GNode *node);
GNode *             g_node_find                         (GNode *root,
                                                         GTraverseType order,
                                                         GTraverseFlags flags,
                                                         gpointer data);
GNode *             g_node_find_child                   (GNode *node,
                                                         GTraverseFlags flags,
                                                         gpointer data);
gint                g_node_child_index                  (GNode *node,
                                                         gpointer data);
gint                g_node_child_position               (GNode *node,
                                                         GNode *child);
#define             g_node_first_child                  (node)
GNode *             g_node_last_child                   (GNode *node);
GNode *             g_node_nth_child                    (GNode *node,
                                                         guint n);
GNode *             g_node_first_sibling                (GNode *node);
#define             g_node_next_sibling                 (node)
#define             g_node_prev_sibling                 (node)
GNode *             g_node_last_sibling                 (GNode *node);

#define             G_NODE_IS_LEAF                      (node)
#define             G_NODE_IS_ROOT                      (node)
guint               g_node_depth                        (GNode *node);
guint               g_node_n_nodes                      (GNode *root,
                                                         GTraverseFlags flags);
guint               g_node_n_children                   (GNode *node);
gboolean            g_node_is_ancestor                  (GNode *node,
                                                         GNode *descendant);
guint               g_node_max_height                   (GNode *root);

void                g_node_unlink                       (GNode *node);
void                g_node_destroy                      (GNode *root);

Description

The GNode struct and its associated functions provide a N-ary tree data structure, where nodes in the tree can contain arbitrary data.

To create a new tree use g_node_new().

To insert a node into a tree use g_node_insert(), g_node_insert_before(), g_node_append() and g_node_prepend().

To create a new node and insert it into a tree use g_node_insert_data(), g_node_insert_data_after(), g_node_insert_data_before(), g_node_append_data() and g_node_prepend_data().

To reverse the children of a node use g_node_reverse_children().

To find a node use g_node_get_root(), g_node_find(), g_node_find_child(), g_node_child_index(), g_node_child_position(), g_node_first_child(), g_node_last_child(), g_node_nth_child(), g_node_first_sibling(), g_node_prev_sibling(), g_node_next_sibling() or g_node_last_sibling().

To get information about a node or tree use G_NODE_IS_LEAF(), G_NODE_IS_ROOT(), g_node_depth(), g_node_n_nodes(), g_node_n_children(), g_node_is_ancestor() or g_node_max_height().

To traverse a tree, calling a function for each node visited in the traversal, use g_node_traverse() or g_node_children_foreach().

To remove a node or subtree from a tree use g_node_unlink() or g_node_destroy().

Details

struct GNode

struct GNode {
  gpointer data;
  GNode	  *next;
  GNode	  *prev;
  GNode	  *parent;
  GNode	  *children;
};

The GNode struct represents one node in a N-ary Tree. fields

gpointer data;

 contains the actual data of the node.

GNode *next;

 points to the node's next sibling (a sibling is another GNode with the same parent).

GNode *prev;

 points to the node's previous sibling.

GNode *parent;

 points to the parent of the GNode, or is NULL if the GNode is the root of the tree.

GNode *children;

 points to the first child of the GNode. The other children are accessed by using the next pointer of each child.

g_node_new ()

GNode *             g_node_new                          (gpointer data);

Creates a new GNode containing the given data. Used to create the first node in a tree.

data :

 the data of the new node

Returns :

 a new GNode

g_node_copy ()

GNode *             g_node_copy                         (GNode *node);

Recursively copies a GNode (but does not deep-copy the data inside the nodes, see g_node_copy_deep() if you need that).

node :

 a GNode

Returns :

 a new GNode containing the same data pointers

GCopyFunc ()

gpointer            (*GCopyFunc)                        (gconstpointer src,
                                                         gpointer data);

A function of this signature is used to copy the node data when doing a deep-copy of a tree.

src :

 A pointer to the data which should be copied

data :

 Additional data

Returns :

 A pointer to the copy

Since 2.4

g_node_copy_deep ()

GNode *             g_node_copy_deep                    (GNode *node,
                                                         GCopyFunc copy_func,
                                                         gpointer data);

Recursively copies a GNode and its data.

node :

 a GNode

copy_func :

 the function which is called to copy the data inside each node, or NULL to use the original data.

data :

 data to pass to copy_func

Returns :

 a new GNode containing copies of the data in node.

Since 2.4

g_node_insert ()

GNode *             g_node_insert                       (GNode *parent,
                                                         gint position,
                                                         GNode *node);

Inserts a GNode beneath the parent at the given position.

parent :

 the GNode to place node under

position :

 the position to place node at, with respect to its siblings If position is -1, node is inserted as the last child of parent

node :

 the GNode to insert

Returns :

 the inserted GNode

g_node_insert_before ()

GNode *             g_node_insert_before                (GNode *parent,
                                                         GNode *sibling,
                                                         GNode *node);

Inserts a GNode beneath the parent before the given sibling.

parent :

 the GNode to place node under

sibling :

 the sibling GNode to place node before. If sibling is NULL, the node is inserted as the last child of parent.

node :

 the GNode to insert

Returns :

 the inserted GNode

g_node_insert_after ()

GNode *             g_node_insert_after                 (GNode *parent,
                                                         GNode *sibling,
                                                         GNode *node);

Inserts a GNode beneath the parent after the given sibling.

parent :

 the GNode to place node under

sibling :

 the sibling GNode to place node after. If sibling is NULL, the node is inserted as the first child of parent.

node :

 the GNode to insert

Returns :

 the inserted GNode

g_node_append()

#define             g_node_append(parent, node)

Inserts a GNode as the last child of the given parent.

parent :

 the GNode to place the new GNode under

node :

 the GNode to insert

Returns :

 the inserted GNode

g_node_prepend ()

GNode *             g_node_prepend                      (GNode *parent,
                                                         GNode *node);

Inserts a GNode as the first child of the given parent.

parent :

 the GNode to place the new GNode under

node :

 the GNode to insert

Returns :

 the inserted GNode

g_node_insert_data()

#define             g_node_insert_data(parent, position, data)

Inserts a new GNode at the given position.

parent :

 the GNode to place the new GNode under

position :

 the position to place the new GNode at. If position is -1, the new GNode is inserted as the last child of parent

data :

 the data for the new GNode

Returns :

 the new GNode

g_node_insert_data_after()

#define             g_node_insert_data_after(parent, sibling, data)

Inserts a new GNode after the given sibling.

parent :

 the GNode to place the new GNode under

sibling :

 the sibling GNode to place the new GNode after

data :

 the data for the new GNode

Returns :

 the new GNode

g_node_insert_data_before()

#define             g_node_insert_data_before(parent, sibling, data)

Inserts a new GNode before the given sibling.

parent :

 the GNode to place the new GNode under

sibling :

 the sibling GNode to place the new GNode before

data :

 the data for the new GNode

Returns :

 the new GNode

g_node_append_data()

#define             g_node_append_data(parent, data)

Inserts a new GNode as the last child of the given parent.

parent :

 the GNode to place the new GNode under

data :

 the data for the new GNode

Returns :

 the new GNode

g_node_prepend_data()

#define             g_node_prepend_data(parent, data)

Inserts a new GNode as the first child of the given parent.

parent :

 the GNode to place the new GNode under

data :

 the data for the new GNode

Returns :

 the new GNode

g_node_reverse_children ()

void                g_node_reverse_children             (GNode *node);

Reverses the order of the children of a GNode. (It doesn't change the order of the grandchildren.)

node :

 a GNode.

g_node_traverse ()

void                g_node_traverse                     (GNode *root,
                                                         GTraverseType order,
                                                         GTraverseFlags flags,
                                                         gint max_depth,
                                                         GNodeTraverseFunc func,
                                                         gpointer data);

Traverses a tree starting at the given root GNode. It calls the given function for each node visited. The traversal can be halted at any point by returning TRUE from func.

root :

 the root GNode of the tree to traverse

order :

 the order in which nodes are visited - G_IN_ORDER, G_PRE_ORDER, G_POST_ORDER, or G_LEVEL_ORDER.

flags :

 which types of children are to be visited, one of G_TRAVERSE_ALL, G_TRAVERSE_LEAVES and G_TRAVERSE_NON_LEAVES

max_depth :

 the maximum depth of the traversal. Nodes below this depth will not be visited. If max_depth is -1 all nodes in the tree are visited. If depth is 1, only the root is visited. If depth is 2, the root and its children are visited. And so on.

func :

 the function to call for each visited GNode

data :

 user data to pass to the function

enum GTraverseFlags

typedef enum {
  G_TRAVERSE_LEAVES     = 1 << 0,
  G_TRAVERSE_NON_LEAVES = 1 << 1,
  G_TRAVERSE_ALL        = G_TRAVERSE_LEAVES | G_TRAVERSE_NON_LEAVES,
  G_TRAVERSE_MASK       = 0x03,
  G_TRAVERSE_LEAFS      = G_TRAVERSE_LEAVES,
  G_TRAVERSE_NON_LEAFS  = G_TRAVERSE_NON_LEAVES
} GTraverseFlags;

Specifies which nodes are visited during several of the tree functions, including g_node_traverse() and g_node_find().

G_TRAVERSE_LEAVES

 only leaf nodes should be visited. This name has been introduced in 2.6, for older version use G_TRAVERSE_LEAFS.

G_TRAVERSE_NON_LEAVES

 only non-leaf nodes should be visited. This name has been introduced in 2.6, for older version use G_TRAVERSE_NON_LEAFS.

G_TRAVERSE_ALL

 all nodes should be visited.

G_TRAVERSE_MASK

 a mask of all traverse flags.

G_TRAVERSE_LEAFS

 identical to G_TRAVERSE_LEAVES.

G_TRAVERSE_NON_LEAFS

 identical to G_TRAVERSE_NON_LEAVES.

GNodeTraverseFunc ()

gboolean            (*GNodeTraverseFunc)                (GNode *node,
                                                         gpointer data);

Specifies the type of function passed to g_node_traverse(). The function is called with each of the nodes visited, together with the user data passed to g_node_traverse(). If the function returns TRUE, then the traversal is stopped.

node :

 a GNode.

data :

 user data passed to g_node_traverse().

Returns :

 TRUE to stop the traversal.

g_node_children_foreach ()

void                g_node_children_foreach             (GNode *node,
                                                         GTraverseFlags flags,
                                                         GNodeForeachFunc func,
                                                         gpointer data);

Calls a function for each of the children of a GNode. Note that it doesn't descend beneath the child nodes.

node :

 a GNode

flags :

 which types of children are to be visited, one of G_TRAVERSE_ALL, G_TRAVERSE_LEAVES and G_TRAVERSE_NON_LEAVES

func :

 the function to call for each visited node

data :

 user data to pass to the function

GNodeForeachFunc ()

void                (*GNodeForeachFunc)                 (GNode *node,
                                                         gpointer data);

Specifies the type of function passed to g_node_children_foreach(). The function is called with each child node, together with the user data passed to g_node_children_foreach().

node :

 a GNode.

data :

 user data passed to g_node_children_foreach().

g_node_get_root ()

GNode *             g_node_get_root                     (GNode *node);

Gets the root of a tree.

node :

 a GNode

Returns :

 the root of the tree

g_node_find ()

GNode *             g_node_find                         (GNode *root,
                                                         GTraverseType order,
                                                         GTraverseFlags flags,
                                                         gpointer data);

Finds a GNode in a tree.

root :

 the root GNode of the tree to search

order :

 the order in which nodes are visited - G_IN_ORDER, G_PRE_ORDER, G_POST_ORDER, or G_LEVEL_ORDER

flags :

 which types of children are to be searched, one of G_TRAVERSE_ALL, G_TRAVERSE_LEAVES and G_TRAVERSE_NON_LEAVES

data :

 the data to find

Returns :

 the found GNode, or NULL if the data is not found

g_node_find_child ()

GNode *             g_node_find_child                   (GNode *node,
                                                         GTraverseFlags flags,
                                                         gpointer data);

Finds the first child of a GNode with the given data.

node :

 a GNode

flags :

 which types of children are to be searched, one of G_TRAVERSE_ALL, G_TRAVERSE_LEAVES and G_TRAVERSE_NON_LEAVES

data :

 the data to find

Returns :

 the found child GNode, or NULL if the data is not found

g_node_child_index ()

gint                g_node_child_index                  (GNode *node,
                                                         gpointer data);

Gets the position of the first child of a GNode which contains the given data.

node :

 a GNode

data :

 the data to find

Returns :

 the index of the child of node which contains data, or -1 if the data is not found

g_node_child_position ()

gint                g_node_child_position               (GNode *node,
                                                         GNode *child);

Gets the position of a GNode with respect to its siblings. child must be a child of node. The first child is numbered 0, the second 1, and so on.

node :

 a GNode

child :

 a child of node

Returns :

 the position of child with respect to its siblings

g_node_first_child()

#define             g_node_first_child(node)

Gets the first child of a GNode.

node :

 a GNode

Returns :

 the first child of node, or NULL if node is NULL or has no children

g_node_last_child ()

GNode *             g_node_last_child                   (GNode *node);

Gets the last child of a GNode.

node :

 a GNode (must not be NULL)

Returns :

 the last child of node, or NULL if node has no children

g_node_nth_child ()

GNode *             g_node_nth_child                    (GNode *node,
                                                         guint n);

Gets a child of a GNode, using the given index. The first child is at index 0. If the index is too big, NULL is returned.

node :

 a GNode

n :

 the index of the desired child

Returns :

 the child of node at index n

g_node_first_sibling ()

GNode *             g_node_first_sibling                (GNode *node);

Gets the first sibling of a GNode. This could possibly be the node itself.

node :

 a GNode

Returns :

 the first sibling of node

g_node_next_sibling()

#define             g_node_next_sibling(node)

Gets the next sibling of a GNode.

node :

 a GNode

Returns :

 the next sibling of node, or NULL if node is the last node or NULL

g_node_prev_sibling()

#define             g_node_prev_sibling(node)

Gets the previous sibling of a GNode.

node :

 a GNode

Returns :

 the previous sibling of node, or NULL if node is the first node or NULL

g_node_last_sibling ()

GNode *             g_node_last_sibling                 (GNode *node);

Gets the last sibling of a GNode. This could possibly be the node itself.

node :

 a GNode

Returns :

 the last sibling of node

G_NODE_IS_LEAF()

#define	 G_NODE_IS_LEAF(node) (((GNode*) (node))->children == NULL)

Returns TRUE if a GNode is a leaf node.

node :

 a GNode

Returns :

 TRUE if the GNode is a leaf node (i.e. it has no children)

G_NODE_IS_ROOT()

#define             G_NODE_IS_ROOT(node)

Returns TRUE if a GNode is the root of a tree.

node :

 a GNode

Returns :

 TRUE if the GNode is the root of a tree (i.e. it has no parent or siblings)

g_node_depth ()

guint               g_node_depth                        (GNode *node);

Gets the depth of a GNode.

If node is NULL the depth is 0. The root node has a depth of 1. For the children of the root node the depth is 2. And so on.

node :

 a GNode

Returns :

 the depth of the GNode

g_node_n_nodes ()

guint               g_node_n_nodes                      (GNode *root,
                                                         GTraverseFlags flags);

Gets the number of nodes in a tree.

root :

 a GNode

flags :

 which types of children are to be counted, one of G_TRAVERSE_ALL, G_TRAVERSE_LEAVES and G_TRAVERSE_NON_LEAVES

Returns :

 the number of nodes in the tree

g_node_n_children ()

guint               g_node_n_children                   (GNode *node);

Gets the number of children of a GNode.

node :

 a GNode

Returns :

 the number of children of node

g_node_is_ancestor ()

gboolean            g_node_is_ancestor                  (GNode *node,
                                                         GNode *descendant);

Returns TRUE if node is an ancestor of descendant. This is true if node is the parent of descendant, or if node is the grandparent of descendant etc.

node :

 a GNode

descendant :

 a GNode

Returns :

 TRUE if node is an ancestor of descendant

g_node_max_height ()

guint               g_node_max_height                   (GNode *root);

Gets the maximum height of all branches beneath a GNode. This is the maximum distance from the GNode to all leaf nodes.

If root is NULL, 0 is returned. If root has no children, 1 is returned. If root has children, 2 is returned. And so on.

root :

 a GNode

Returns :

 the maximum height of the tree beneath root

g_node_unlink ()

void                g_node_unlink                       (GNode *node);

Unlinks a GNode from a tree, resulting in two separate trees.

node :

 the GNode to unlink, which becomes the root of a new tree

g_node_destroy ()

void                g_node_destroy                      (GNode *root);

Removes root and its children from the tree, freeing any memory allocated.

root :

 the root of the tree/subtree to destroy
Generated by GTK-Doc V1.18.1