<!-- ##### SECTION Title ##### -->Sequences<!-- ##### SECTION Short_Description ##### -->scalable lists<!-- ##### SECTION Long_Description ##### --><para>The #GSequence data structure has the API of a list, but isimplemented internally with a balanced binary tree. This means that itis possible to maintain a sorted list of n elements in time O(n logn). The data contained in each element can be either integer values, byusing of the <link linkend="glib-Type-Conversion-Macros">Type Conversion Macros</link>,or simply pointers to any type of data.</para><para>A #GSequence is accessed through <firstterm>iterators</firstterm>,represented by a #GSequenceIter. An iterator represents a positionbetween two elements of the sequence. For example, the<firstterm>begin</firstterm> iterator represents the gap immediatelybefore the first element of the sequence, and the<firstterm>end</firstterm> iterator represents the gap immediatelyafter the last element. In an empty sequence, the begin and enditerators are the same.</para><para>Some methods on #GSequence operate on ranges of items. For exampleg_sequence_foreach_range() will call a user-specified function on eachelement with the given range. The range is delimited by the gapsrepresented by the passed-in iterators, so if you pass in the beginand end iterators, the range in question is the entire sequence.</para><para>The function g_sequence_get() is used with an iterator to access theelement immediately following the gap that the iteratorrepresents. The iterator is said to <firstterm>point</firstterm> tothat element.</para><para>Iterators are stable across most operations on a #GSequence. Forexample an iterator pointing to some element of a sequence willcontinue to point to that element even after the sequence issorted. Even moving an element to another sequence using for exampleg_sequence_move_range() will not invalidate the iterators pointing toit. The only operation that will invalidate an iterator is when theelement it points to is removed from any sequence.</para><!-- ##### SECTION See_Also ##### --><para></para><!-- ##### SECTION Stability_Level ##### --><!-- ##### STRUCT GSequence ##### --><para>The <structname>GSequence</structname> struct is an opaque data typerepresenting a <link linkend="glib-Sequences">Sequence</link> data type.</para><!-- ##### TYPEDEF GSequenceIter ##### --><para>The <structname>GSequenceIter</structname> struct is an opaque datatype representing an iterator pointing into a #GSequence.</para><!-- ##### USER_FUNCTION GSequenceIterCompareFunc ##### --><para>A #GSequenceIterCompareFunc is a function used to compareiterators. It must return zero if the iterators compare equal, anegative value if @a comes before @b, and a positive value if @b comesbefore @a.</para>@a: a #GSequenceIter@b: a #GSequenceIter@data: user data@Returns: zero if the iterators are equal, a negative value if @acomes before @b, and a positive value if @b comes before @a.<!-- ##### FUNCTION g_sequence_new ##### --><para></para>@data_destroy: @Returns: <!-- ##### FUNCTION g_sequence_free ##### --><para></para>@seq: <!-- ##### FUNCTION g_sequence_get_length ##### --><para></para>@seq: @Returns: <!-- ##### FUNCTION g_sequence_foreach ##### --><para></para>@seq: @func: @user_data: <!-- ##### FUNCTION g_sequence_foreach_range ##### --><para></para>@begin: @end: @func: @user_data: <!-- ##### FUNCTION g_sequence_sort ##### --><para></para>@seq: @cmp_func: @cmp_data: <!-- ##### FUNCTION g_sequence_sort_iter ##### --><para></para>@seq: @cmp_func: @cmp_data: <!-- ##### FUNCTION g_sequence_get_begin_iter ##### --><para></para>@seq: @Returns: <!-- ##### FUNCTION g_sequence_get_end_iter ##### --><para></para>@seq: @Returns: <!-- ##### FUNCTION g_sequence_get_iter_at_pos ##### --><para></para>@seq: @pos: @Returns: <!-- ##### FUNCTION g_sequence_append ##### --><para></para>@seq: @data: @Returns: <!-- ##### FUNCTION g_sequence_prepend ##### --><para></para>@seq: @data: @Returns: <!-- ##### FUNCTION g_sequence_insert_before ##### --><para></para>@iter: @data: @Returns: <!-- ##### FUNCTION g_sequence_move ##### --><para></para>@src: @dest: <!-- ##### FUNCTION g_sequence_swap ##### --><para></para>@a: @b: <!-- ##### FUNCTION g_sequence_insert_sorted ##### --><para></para>@seq: @data: @cmp_func: @cmp_data: @Returns: <!-- ##### FUNCTION g_sequence_insert_sorted_iter ##### --><para></para>@seq: @data: @iter_cmp: @cmp_data: @Returns: <!-- ##### FUNCTION g_sequence_sort_changed ##### --><para></para>@iter: @cmp_func: @cmp_data: <!-- ##### FUNCTION g_sequence_sort_changed_iter ##### --><para></para>@iter: @iter_cmp: @cmp_data: <!-- ##### FUNCTION g_sequence_remove ##### --><para></para>@iter: <!-- ##### FUNCTION g_sequence_remove_range ##### --><para></para>@begin: @end: <!-- ##### FUNCTION g_sequence_move_range ##### --><para></para>@dest: @begin: @end: <!-- ##### FUNCTION g_sequence_search ##### --><para></para>@seq: @data: @cmp_func: @cmp_data: @Returns: <!-- ##### FUNCTION g_sequence_search_iter ##### --><para></para>@seq: @data: @iter_cmp: @cmp_data: @Returns: <!-- ##### FUNCTION g_sequence_get ##### --><para></para>@iter: @Returns: <!-- ##### FUNCTION g_sequence_set ##### --><para></para>@iter: @data: <!-- ##### FUNCTION g_sequence_iter_is_begin ##### --><para></para>@iter: @Returns: <!-- ##### FUNCTION g_sequence_iter_is_end ##### --><para></para>@iter: @Returns: <!-- ##### FUNCTION g_sequence_iter_next ##### --><para></para>@iter: @Returns: <!-- ##### FUNCTION g_sequence_iter_prev ##### --><para></para>@iter: @Returns: <!-- ##### FUNCTION g_sequence_iter_get_position ##### --><para></para>@iter: @Returns: <!-- ##### FUNCTION g_sequence_iter_move ##### --><para></para>@iter: @delta: @Returns: <!-- ##### FUNCTION g_sequence_iter_get_sequence ##### --><para></para>@iter: @Returns: <!-- ##### FUNCTION g_sequence_iter_compare ##### --><para></para>@a: @b: @Returns: <!-- ##### FUNCTION g_sequence_range_get_midpoint ##### --><para></para>@begin: @end: @Returns: