Sequences

Sequences — scalable lists

Synopsis


#include <glib.h>


                    GSequence;
typedef             GSequenceIter;
gint                (*GSequenceIterCompareFunc)         (GSequenceIter *a,
                                                         GSequenceIter *b,
                                                         gpointer data);

GSequence*          g_sequence_new                      (GDestroyNotify data_destroy);
void                g_sequence_free                     (GSequence *seq);
gint                g_sequence_get_length               (GSequence *seq);
void                g_sequence_foreach                  (GSequence *seq,
                                                         GFunc func,
                                                         gpointer user_data);
void                g_sequence_foreach_range            (GSequenceIter *begin,
                                                         GSequenceIter *end,
                                                         GFunc func,
                                                         gpointer user_data);
void                g_sequence_sort                     (GSequence *seq,
                                                         GCompareDataFunc cmp_func,
                                                         gpointer cmp_data);
void                g_sequence_sort_iter                (GSequence *seq,
                                                         GSequenceIterCompareFunc cmp_func,
                                                         gpointer cmp_data);

GSequenceIter*      g_sequence_get_begin_iter           (GSequence *seq);
GSequenceIter*      g_sequence_get_end_iter             (GSequence *seq);
GSequenceIter*      g_sequence_get_iter_at_pos          (GSequence *seq,
                                                         gint pos);
GSequenceIter*      g_sequence_append                   (GSequence *seq,
                                                         gpointer data);
GSequenceIter*      g_sequence_prepend                  (GSequence *seq,
                                                         gpointer data);
GSequenceIter*      g_sequence_insert_before            (GSequenceIter *iter,
                                                         gpointer data);
void                g_sequence_move                     (GSequenceIter *src,
                                                         GSequenceIter *dest);
void                g_sequence_swap                     (GSequenceIter *a,
                                                         GSequenceIter *b);
GSequenceIter*      g_sequence_insert_sorted            (GSequence *seq,
                                                         gpointer data,
                                                         GCompareDataFunc cmp_func,
                                                         gpointer cmp_data);
GSequenceIter*      g_sequence_insert_sorted_iter       (GSequence *seq,
                                                         gpointer data,
                                                         GSequenceIterCompareFunc iter_cmp,
                                                         gpointer cmp_data);
void                g_sequence_sort_changed             (GSequenceIter *iter,
                                                         GCompareDataFunc cmp_func,
                                                         gpointer cmp_data);
void                g_sequence_sort_changed_iter        (GSequenceIter *iter,
                                                         GSequenceIterCompareFunc iter_cmp,
                                                         gpointer cmp_data);
void                g_sequence_remove                   (GSequenceIter *iter);
void                g_sequence_remove_range             (GSequenceIter *begin,
                                                         GSequenceIter *end);
void                g_sequence_move_range               (GSequenceIter *dest,
                                                         GSequenceIter *begin,
                                                         GSequenceIter *end);
GSequenceIter*      g_sequence_search                   (GSequence *seq,
                                                         gpointer data,
                                                         GCompareDataFunc cmp_func,
                                                         gpointer cmp_data);
GSequenceIter*      g_sequence_search_iter              (GSequence *seq,
                                                         gpointer data,
                                                         GSequenceIterCompareFunc iter_cmp,
                                                         gpointer cmp_data);

gpointer            g_sequence_get                      (GSequenceIter *iter);
void                g_sequence_set                      (GSequenceIter *iter,
                                                         gpointer data);

gboolean            g_sequence_iter_is_begin            (GSequenceIter *iter);
gboolean            g_sequence_iter_is_end              (GSequenceIter *iter);
GSequenceIter*      g_sequence_iter_next                (GSequenceIter *iter);
GSequenceIter*      g_sequence_iter_prev                (GSequenceIter *iter);
gint                g_sequence_iter_get_position        (GSequenceIter *iter);
GSequenceIter*      g_sequence_iter_move                (GSequenceIter *iter,
                                                         gint delta);
GSequence*          g_sequence_iter_get_sequence        (GSequenceIter *iter);

gint                g_sequence_iter_compare             (GSequenceIter *a,
                                                         GSequenceIter *b);
GSequenceIter*      g_sequence_range_get_midpoint       (GSequenceIter *begin,
                                                         GSequenceIter *end);

Description

The GSequence data structure has the API of a list, but is implemented internally with a balanced binary tree. This means that it is possible to maintain a sorted list of n elements in time O(n log n). The data contained in each element can be either integer values, by using of the Type Conversion Macros, or simply pointers to any type of data.

A GSequence is accessed through iterators, represented by a GSequenceIter. An iterator represents a position between two elements of the sequence. For example, the begin iterator represents the gap immediately before the first element of the sequence, and the end iterator represents the gap immediately after the last element. In an empty sequence, the begin and end iterators are the same.

Some methods on GSequence operate on ranges of items. For example g_sequence_foreach_range() will call a user-specified function on each element with the given range. The range is delimited by the gaps represented by the passed-in iterators, so if you pass in the begin and end iterators, the range in question is the entire sequence.

The function g_sequence_get() is used with an iterator to access the element immediately following the gap that the iterator represents. The iterator is said to point to that element.

Iterators are stable across most operations on a GSequence. For example an iterator pointing to some element of a sequence will continue to point to that element even after the sequence is sorted. Even moving an element to another sequence using for example g_sequence_move_range() will not invalidate the iterators pointing to it. The only operation that will invalidate an iterator is when the element it points to is removed from any sequence.

Details

GSequence

typedef struct _GSequence GSequence;

The GSequence struct is an opaque data type representing a Sequence data type.


GSequenceIter

typedef struct _GSequenceNode  GSequenceIter;

The GSequenceIter struct is an opaque data type representing an iterator pointing into a GSequence.


GSequenceIterCompareFunc ()

gint                (*GSequenceIterCompareFunc)         (GSequenceIter *a,
                                                         GSequenceIter *b,
                                                         gpointer data);

A GSequenceIterCompareFunc is a function used to compare iterators. It must return zero if the iterators compare equal, a negative value if a comes before b, and a positive value if b comes before a.

a :

a GSequenceIter

b :

a GSequenceIter

data :

user data

Returns :

zero if the iterators are equal, a negative value if a comes before b, and a positive value if b comes before a.

g_sequence_new ()

GSequence*          g_sequence_new                      (GDestroyNotify data_destroy);

Creates a new GSequence. The data_destroy function, if non-NULL will be called on all items when the sequence is destroyed and on items that are removed from the sequence.

data_destroy :

a GDestroyNotify function, or NULL

Returns :

a new GSequence

Since 2.14


g_sequence_free ()

void                g_sequence_free                     (GSequence *seq);

Frees the memory allocated for seq. If seq has a data destroy function associated with it, that function is called on all items in seq.

seq :

a GSequence

Since 2.14


g_sequence_get_length ()

gint                g_sequence_get_length               (GSequence *seq);

Returns the length of seq

seq :

a GSequence

Returns :

the length of seq

Since 2.14


g_sequence_foreach ()

void                g_sequence_foreach                  (GSequence *seq,
                                                         GFunc func,
                                                         gpointer user_data);

Calls func for each item in the sequence passing user_data to the function.

seq :

a GSequence

func :

the function to call for each item in seq

user_data :

user data passed to func

Since 2.14


g_sequence_foreach_range ()

void                g_sequence_foreach_range            (GSequenceIter *begin,
                                                         GSequenceIter *end,
                                                         GFunc func,
                                                         gpointer user_data);

Calls func for each item in the range (begin, end) passing user_data to the function.

begin :

a GSequenceIter

end :

a GSequenceIter

func :

a GFunc

user_data :

user data passed to func

Since 2.14


g_sequence_sort ()

void                g_sequence_sort                     (GSequence *seq,
                                                         GCompareDataFunc cmp_func,
                                                         gpointer cmp_data);

Sorts seq using cmp_func.

seq :

a GSequence

cmp_func :

the GCompareDataFunc used to sort seq. This function is passed two items of seq and should return 0 if they are equal, a negative value fi the first comes before the second, and a positive value if the second comes before the first.

cmp_data :

user data passed to cmp_func

Since 2.14


g_sequence_sort_iter ()

void                g_sequence_sort_iter                (GSequence *seq,
                                                         GSequenceIterCompareFunc cmp_func,
                                                         gpointer cmp_data);

Like g_sequence_sort(), but uses a GSequenceIterCompareFunc instead of a GCompareDataFunc as the compare function

seq :

a GSequence

cmp_func :

the GSequenceItercompare used to compare iterators in the sequence. It is called with two iterators pointing into seq. It should return 0 if the iterators are equal, a negative value if the first iterator comes before the second, and a positive value if the second iterator comes before the first.

cmp_data :

user data passed to cmp_func

Since 2.14


g_sequence_get_begin_iter ()

GSequenceIter*      g_sequence_get_begin_iter           (GSequence *seq);

Returns the begin iterator for seq.

seq :

a GSequence

Returns :

the begin iterator for seq.

Since 2.14


g_sequence_get_end_iter ()

GSequenceIter*      g_sequence_get_end_iter             (GSequence *seq);

Returns the end iterator for seg

seq :

a GSequence

Returns :

the end iterator for seq

Since 2.14


g_sequence_get_iter_at_pos ()

GSequenceIter*      g_sequence_get_iter_at_pos          (GSequence *seq,
                                                         gint pos);

Returns the iterator at position pos. If pos is negative or larger than the number of items in seq, the end iterator is returned.

seq :

a GSequence

pos :

a position in seq, or -1 for the end.

Returns :

The GSequenceIter at position pos

Since 2.14


g_sequence_append ()

GSequenceIter*      g_sequence_append                   (GSequence *seq,
                                                         gpointer data);

Adds a new item to the end of seq.

seq :

a GSequencePointer

data :

the data for the new item

Returns :

an iterator pointing to the new item

Since 2.14


g_sequence_prepend ()

GSequenceIter*      g_sequence_prepend                  (GSequence *seq,
                                                         gpointer data);

Adds a new item to the front of seq

seq :

a GSequence

data :

the data for the new item

Returns :

an iterator pointing to the new item

Since 2.14


g_sequence_insert_before ()

GSequenceIter*      g_sequence_insert_before            (GSequenceIter *iter,
                                                         gpointer data);

Inserts a new item just before the item pointed to by iter.

iter :

a GSequenceIter

data :

the data for the new item

Returns :

an iterator pointing to the new item

Since 2.14


g_sequence_move ()

void                g_sequence_move                     (GSequenceIter *src,
                                                         GSequenceIter *dest);

Moves the item pointed to by src to the position indicated by dest. After calling this function dest will point to the position immediately after src. It is allowed for src and dest to point into different sequences.

src :

a GSequenceIter pointing to the item to move

dest :

a GSequenceIter pointing to the position to which the item is moved.

Since 2.14


g_sequence_swap ()

void                g_sequence_swap                     (GSequenceIter *a,
                                                         GSequenceIter *b);

Swaps the items pointed to by a and b. It is allowed for a and b to point into difference sequences.

Since 2.14


g_sequence_insert_sorted ()

GSequenceIter*      g_sequence_insert_sorted            (GSequence *seq,
                                                         gpointer data,
                                                         GCompareDataFunc cmp_func,
                                                         gpointer cmp_data);

Inserts data into sequence using func to determine the new position. The sequence must already be sorted according to cmp_func; otherwise the new position of data is undefined.

seq :

a GSequence

data :

the data to insert

cmp_func :

the GCompareDataFunc used to compare items in the sequence. It is called with two items of the seq and user_data. It should return 0 if the items are equal, a negative value if the first item comes before the second, and a positive value if the second item comes before the first.

cmp_data :

user data passed to cmp_func.

Returns :

a GSequenceIter pointing to the new item.

Since 2.14


g_sequence_insert_sorted_iter ()

GSequenceIter*      g_sequence_insert_sorted_iter       (GSequence *seq,
                                                         gpointer data,
                                                         GSequenceIterCompareFunc iter_cmp,
                                                         gpointer cmp_data);

Like g_sequence_insert_sorted(), but uses a GSequenceIterCompareFunc instead of a GCompareDataFunc as the compare function.

seq :

a GSequence

data :

data for the new item

iter_cmp :

the GSequenceItercompare used to compare iterators in the sequence. It is called with two iterators pointing into seq. It should return 0 if the iterators are equal, a negative value if the first iterator comes before the second, and a positive value if the second iterator comes before the first.

cmp_data :

user data passed to cmp_func

Returns :

a GSequenceIter pointing to the new item

Since 2.14


g_sequence_sort_changed ()

void                g_sequence_sort_changed             (GSequenceIter *iter,
                                                         GCompareDataFunc cmp_func,
                                                         gpointer cmp_data);

Moves the data pointed to a new position as indicated by cmp_func. This function should be called for items in a sequence already sorted according to cmp_func whenever some aspect of an item changes so that cmp_func may return different values for that item.

iter :

A GSequenceIter

cmp_func :

the GCompareDataFunc used to compare items in the sequence. It is called with two items of the seq and user_data. It should return 0 if the items are equal, a negative value if the first item comes before the second, and a positive value if the second item comes before the first.

cmp_data :

user data passed to cmp_func.

Since 2.14


g_sequence_sort_changed_iter ()

void                g_sequence_sort_changed_iter        (GSequenceIter *iter,
                                                         GSequenceIterCompareFunc iter_cmp,
                                                         gpointer cmp_data);

Like g_sequence_sort_changed(), but uses a GSequenceIterCompareFunc instead of a GCompareDataFunc as the compare function.

iter :

a GSequenceIter

iter_cmp :

the GSequenceItercompare used to compare iterators in the sequence. It is called with two iterators pointing into seq. It should return 0 if the iterators are equal, a negative value if the first iterator comes before the second, and a positive value if the second iterator comes before the first.

cmp_data :

user data passed to cmp_func

Since 2.14


g_sequence_remove ()

void                g_sequence_remove                   (GSequenceIter *iter);

Removes the item pointed to by iter. It is an error to pass the end iterator to this function.

If the sequnce has a data destroy function associated with it, this function is called on the data for the removed item.

iter :

a GSequenceIter

Since 2.14


g_sequence_remove_range ()

void                g_sequence_remove_range             (GSequenceIter *begin,
                                                         GSequenceIter *end);

Removes all items in the (begin, end) range.

If the sequence has a data destroy function associated with it, this function is called on the data for the removed items.

begin :

a GSequenceIter

end :

a GSequenceIter

Since 2.14


g_sequence_move_range ()

void                g_sequence_move_range               (GSequenceIter *dest,
                                                         GSequenceIter *begin,
                                                         GSequenceIter *end);

Inserts the (begin, end) range at the destination pointed to by ptr. The begin and end iters must point into the same sequence. It is allowed for dest to point to a different sequence than the one pointed into by begin and end.

If dest is NULL, the range indicated by begin and end is removed from the sequence. If dest iter points to a place within the (begin, end) range, the range does not move.

dest :

a GSequenceIter

begin :

a GSequenceIter

end :

a GSequenceIter

Since 2.14


g_sequence_search ()

GSequenceIter*      g_sequence_search                   (GSequence *seq,
                                                         gpointer data,
                                                         GCompareDataFunc cmp_func,
                                                         gpointer cmp_data);

Returns an iterator pointing to the position where data would be inserted according to cmp_func and cmp_data.

seq :

a GSequence

data :

data for the new item

cmp_func :

the GCompareDataFunc used to compare items in the sequence. It is called with two items of the seq and user_data. It should return 0 if the items are equal, a negative value if the first item comes before the second, and a positive value if the second item comes before the first.

cmp_data :

user data passed to cmp_func.

Returns :

an GSequenceIter pointing to the position where data would have been inserted according to cmp_func and cmp_data.

Since 2.14


g_sequence_search_iter ()

GSequenceIter*      g_sequence_search_iter              (GSequence *seq,
                                                         gpointer data,
                                                         GSequenceIterCompareFunc iter_cmp,
                                                         gpointer cmp_data);

Like g_sequence_search(), but uses a GSequenceIterCompareFunc instead of a GCompareDataFunc as the compare function.

seq :

a GSequence

data :

data for the new item

iter_cmp :

the GSequenceIterCompare function used to compare iterators in the sequence. It is called with two iterators pointing into seq. It should return 0 if the iterators are equal, a negative value if the first iterator comes before the second, and a positive value if the second iterator comes before the first.

cmp_data :

user data passed to iter_cmp

Returns :

a GSequenceIter pointing to the position in seq where data would have been inserted according to iter_cmp and cmp_data.

Since 2.14


g_sequence_get ()

gpointer            g_sequence_get                      (GSequenceIter *iter);

Returns the data that iter points to.

iter :

a GSequenceIter

Returns :

the data that iter points to

Since 2.14


g_sequence_set ()

void                g_sequence_set                      (GSequenceIter *iter,
                                                         gpointer data);

Changes the data for the item pointed to by iter to be data. If the sequence has a data destroy function associated with it, that function is called on the existing data that iter pointed to.

iter :

a GSequenceIter

data :

new data for the item

Since 2.14


g_sequence_iter_is_begin ()

gboolean            g_sequence_iter_is_begin            (GSequenceIter *iter);

Returns whether iter is the begin iterator

iter :

a GSequenceIter

Returns :

whether iter is the begin iterator

Since 2.14


g_sequence_iter_is_end ()

gboolean            g_sequence_iter_is_end              (GSequenceIter *iter);

Returns whether iter is the end iterator

iter :

a GSequenceIter

Returns :

Whether iter is the end iterator.

Since 2.14


g_sequence_iter_next ()

GSequenceIter*      g_sequence_iter_next                (GSequenceIter *iter);

Returns an iterator pointing to the next position after iter. If iter is the end iterator, the end iterator is returned.

iter :

a GSequenceIter

Returns :

a GSequenceIter pointing to the next position after iter.

Since 2.14


g_sequence_iter_prev ()

GSequenceIter*      g_sequence_iter_prev                (GSequenceIter *iter);

Returns an iterator pointing to the previous position before iter. If iter is the begin iterator, the begin iterator is returned.

iter :

a GSequenceIter

Returns :

a GSequenceIter pointing to the previous position before iter.

Since 2.14


g_sequence_iter_get_position ()

gint                g_sequence_iter_get_position        (GSequenceIter *iter);

Returns the position of iter

iter :

a GSequenceIter

Returns :

the position of iter

Since 2.14


g_sequence_iter_move ()

GSequenceIter*      g_sequence_iter_move                (GSequenceIter *iter,
                                                         gint delta);

Returns the GSequenceIter which is delta positions away from iter. If iter is closer than -delta positions to the beginning of the sequence, the begin iterator is returned. If iter is closer than delta positions to the end of the sequence, the end iterator is returned.

iter :

a GSequenceIter

delta :

A positive or negative number indicating how many positions away from iter the returned GSequenceIter will be.

Returns :

a GSequenceIter which is delta positions away from iter.

Since 2.14


g_sequence_iter_get_sequence ()

GSequence*          g_sequence_iter_get_sequence        (GSequenceIter *iter);

Returns the GSequence that iter points into.

iter :

a GSequenceIter

Returns :

the GSequence that iter points into.

Since 2.14


g_sequence_iter_compare ()

gint                g_sequence_iter_compare             (GSequenceIter *a,
                                                         GSequenceIter *b);

Returns a negative number if a comes before b, 0 if they are equal, and a positive number if a comes after b.

The a and b iterators must point into the same sequence.

a :

a GSequenceIter

b :

a GSequenceIter

Returns :

A negative number if a comes before b, 0 if they are equal, and a positive number if a comes after b.

Since 2.14


g_sequence_range_get_midpoint ()

GSequenceIter*      g_sequence_range_get_midpoint       (GSequenceIter *begin,
                                                         GSequenceIter *end);

Finds an iterator somewhere in the range (begin, end). This iterator will be close to the middle of the range, but is not guaranteed to be exactly in the middle.

The begin and end iterators must both point to the same sequence and begin must come before or be equal to end in the sequence.

begin :

a GSequenceIter

end :

a GSequenceIter

Returns :

A GSequenceIter pointing somewhere in the (begin, end) range.

Since 2.14