@node Container data types
@section Container data types

@c Copyright (C) 2019--2021 Free Software Foundation, Inc.

@c Permission is granted to copy, distribute and/or modify this document
@c under the terms of the GNU Free Documentation License, Version 1.3 or
@c any later version published by the Free Software Foundation; with no
@c Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.  A
@c copy of the license is at <https://www.gnu.org/licenses/fdl-1.3.en.html>.

@c Written by Bruno Haible.

@c This macro expands to \log in TeX mode, but just 'log' in HTML and info
@c modes.
@ifnottex
@macro log
log
@end macro
@end ifnottex

@c This macro expands to \mathopsup in TeX mode, to a superscript in HTML
@c mode, and to ^ without braces in info mode.
@ifhtml
@macro mathopsup {EXP}
@sup{\EXP\}
@end macro
@end ifhtml
@ifinfo
@macro mathopsup {EXP}
^\EXP\
@end macro
@end ifinfo

Gnulib provides several generic container data types.  They can be used
to organize collections of application-defined objects.

@multitable @columnfractions .15 .5 .1 .1 .15
@headitem Data type
@tab Details
@tab Module
@tab Main include file
@tab Include file for operations with out-of-memory checking
@item Sequential list
@tab Can contain any number of objects in any given order.
     Duplicates are allowed, but can optionally be forbidden.
@tab @code{list}
@tab @code{"gl_list.h"}
@tab @code{"gl_xlist.h"}
@item Set
@tab Can contain any number of objects; the order does not matter.
     Duplicates (in the sense of the comparator) are forbidden.
@tab @code{set}
@tab @code{"gl_set.h"}
@tab @code{"gl_xset.h"}
@item Ordered set
@tab Can contain any number of objects in the order of a given comparator
     function.
     Duplicates (in the sense of the comparator) are forbidden.
@tab @code{oset}
@tab @code{"gl_oset.h"}
@tab @code{"gl_xoset.h"}
@item Map
@tab Can contain any number of (key, value) pairs, where keys and values
     are objects;
     there are no (key, value1) and (key, value2) pairs with the same key
     (in the sense of a given comparator function).
@tab @code{map}
@tab @code{"gl_map.h"}
@tab @code{"gl_xmap.h"}
@item Ordered map
@tab Can contain any number of (key, value) pairs, where keys and values
     are objects;
     the (key, value) pairs are ordered by the key, in the order of a given
     comparator function;
     there are no (key, value1) and (key, value2) pairs with the same key
     (in the sense of the comparator function).
@tab @code{omap}
@tab @code{"gl_omap.h"}
@tab @code{"gl_xomap.h"}
@end multitable

Operations without out-of-memory checking (suitable for use in libraries) are
declared in the ``main include file''.  Whereas operations with out-of-memory
checking (suitable only in programs) are declared in the ``include file for
operations with out-of-memory checking''.

For each of the data types, several implementations are available, with
different performance profiles with respect to the available operations.
This enables you to start with the simplest implementation (ARRAY) initially,
and switch to a more suitable implementation after profiling your application.
The implementation of each container instance is specified in a single place
only: in the invocation of the function @code{gl_*_create_empty} that creates
the instance.

The implementations and the guaranteed average performance for the operations
for the ``sequential list'' data type are:

@multitable @columnfractions 0.2 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1
@headitem Operation
@tab ARRAY
@tab CARRAY
@tab LINKED
@tab TREE
@tab LINKEDHASH with duplicates
@tab LINKEDHASH without duplicates
@tab TREEHASH with duplicates
@tab TREEHASH without duplicates
@item @code{gl_list_size}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(1)}
@item @code{gl_list_node_value}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(1)}
@item @code{gl_list_node_set_value}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O((@log n)@mathopsup{2})}
@tab @math{O(1)}
@item @code{gl_list_next_node}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(@log n)}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(@log n)}
@tab @math{O(@log n)}
@item @code{gl_list_previous_node}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(@log n)}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(@log n)}
@tab @math{O(@log n)}
@item @code{gl_list_get_at}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(n)}
@tab @math{O(@log n)}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(@log n)}
@tab @math{O(@log n)}
@item @code{gl_list_get_first}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(@log n)}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(@log n)}
@tab @math{O(@log n)}
@item @code{gl_list_get_last}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(@log n)}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(@log n)}
@tab @math{O(@log n)}
@item @code{gl_list_set_at}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(n)}
@tab @math{O(@log n)}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O((@log n)@mathopsup{2})}
@tab @math{O(@log n)}
@item @code{gl_list_set_first}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(@log n)}
@tab @math{O(n)}
@tab @math{O(1)}
@tab @math{O((@log n)@mathopsup{2})}
@tab @math{O(@log n)}
@item @code{gl_list_set_last}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(@log n)}
@tab @math{O(n)}
@tab @math{O(1)}
@tab @math{O((@log n)@mathopsup{2})}
@tab @math{O(@log n)}
@item @code{gl_list_search}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(1)}
@tab @math{O(@log n)}
@tab @math{O(1)}
@item @code{gl_list_search_from}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(1)}
@tab @math{O((@log n)@mathopsup{2})}
@tab @math{O(@log n)}
@item @code{gl_list_search_from_to}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(1)}
@tab @math{O((@log n)@mathopsup{2})}
@tab @math{O(@log n)}
@item @code{gl_list_indexof}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(@log n)}
@tab @math{O(@log n)}
@item @code{gl_list_indexof_from}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O((@log n)@mathopsup{2})}
@tab @math{O(@log n)}
@item @code{gl_list_indexof_from_to}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O((@log n)@mathopsup{2})}
@tab @math{O(@log n)}
@item @code{gl_list_add_first}
@tab @math{O(n)}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(@log n)}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O((@log n)@mathopsup{2})}
@tab @math{O(@log n)}
@item @code{gl_list_add_last}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(@log n)}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O((@log n)@mathopsup{2})}
@tab @math{O(@log n)}
@item @code{gl_list_add_before}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(1)}
@tab @math{O(@log n)}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O((@log n)@mathopsup{2})}
@tab @math{O(@log n)}
@item @code{gl_list_add_after}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(1)}
@tab @math{O(@log n)}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O((@log n)@mathopsup{2})}
@tab @math{O(@log n)}
@item @code{gl_list_add_at}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(@log n)}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O((@log n)@mathopsup{2})}
@tab @math{O(@log n)}
@item @code{gl_list_remove_node}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(1)}
@tab @math{O(@log n)}
@tab @math{O(n)}
@tab @math{O(1)}
@tab @math{O((@log n)@mathopsup{2})}
@tab @math{O(@log n)}
@item @code{gl_list_remove_at}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(@log n)}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O((@log n)@mathopsup{2})}
@tab @math{O(@log n)}
@item @code{gl_list_remove_first}
@tab @math{O(n)}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(@log n)}
@tab @math{O(n)}
@tab @math{O(1)}
@tab @math{O((@log n)@mathopsup{2})}
@tab @math{O(@log n)}
@item @code{gl_list_remove_last}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(@log n)}
@tab @math{O(n)}
@tab @math{O(1)}
@tab @math{O((@log n)@mathopsup{2})}
@tab @math{O(@log n)}
@item @code{gl_list_remove}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(1)}
@tab @math{O((@log n)@mathopsup{2})}
@tab @math{O(@log n)}
@item @code{gl_list_iterator}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(@log n)}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(@log n)}
@tab @math{O(@log n)}
@item @code{gl_list_iterator_from_to}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(n)}
@tab @math{O(@log n)}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(@log n)}
@tab @math{O(@log n)}
@item @code{gl_list_iterator_next}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(@log n)}
@tab @math{O(1)}
@tab @math{O(1)}
@tab @math{O(@log n)}
@tab @math{O(@log n)}
@item @code{gl_sortedlist_search}
@tab @math{O(@log n)}
@tab @math{O(@log n)}
@tab @math{O(n)}
@tab @math{O(@log n)}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(@log n)}
@tab @math{O(@log n)}
@item @code{gl_sortedlist_search_from}
@tab @math{O(@log n)}
@tab @math{O(@log n)}
@tab @math{O(n)}
@tab @math{O(@log n)}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(@log n)}
@tab @math{O(@log n)}
@item @code{gl_sortedlist_indexof}
@tab @math{O(@log n)}
@tab @math{O(@log n)}
@tab @math{O(n)}
@tab @math{O(@log n)}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(@log n)}
@tab @math{O(@log n)}
@item @code{gl_sortedlist_indexof_from}
@tab @math{O(@log n)}
@tab @math{O(@log n)}
@tab @math{O(n)}
@tab @math{O(@log n)}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(@log n)}
@tab @math{O(@log n)}
@item @code{gl_sortedlist_add}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(@log n)}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O((@log n)@mathopsup{2})}
@tab @math{O(@log n)}
@item @code{gl_sortedlist_remove}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O(@log n)}
@tab @math{O(n)}
@tab @math{O(n)}
@tab @math{O((@log n)@mathopsup{2})}
@tab @math{O(@log n)}
@end multitable

The implementations and the guaranteed average performance for the operations
for the ``set'' data type are:

@multitable @columnfractions 0.4 0.2 0.4
@headitem Operation
@tab ARRAY
@tab LINKEDHASH, HASH
@item @code{gl_set_size}
@tab @math{O(1)}
@tab @math{O(1)}
@item @code{gl_set_add}
@tab @math{O(n)}
@tab @math{O(1)}
@item @code{gl_set_remove}
@tab @math{O(n)}
@tab @math{O(1)}
@item @code{gl_set_search}
@tab @math{O(n)}
@tab @math{O(1)}
@item @code{gl_set_iterator}
@tab @math{O(1)}
@tab @math{O(1)}
@item @code{gl_set_iterator_next}
@tab @math{O(1)}
@tab @math{O(1)}
@end multitable

The implementations and the guaranteed average performance for the operations
for the ``ordered set'' data type are:

@multitable @columnfractions 0.5 0.25 0.25
@headitem Operation
@tab ARRAY
@tab TREE
@item @code{gl_oset_size}
@tab @math{O(1)}
@tab @math{O(1)}
@item @code{gl_oset_add}
@tab @math{O(n)}
@tab @math{O(@log n)}
@item @code{gl_oset_remove}
@tab @math{O(n)}
@tab @math{O(@log n)}
@item @code{gl_oset_search}
@tab @math{O(@log n)}
@tab @math{O(@log n)}
@item @code{gl_oset_search_atleast}
@tab @math{O(@log n)}
@tab @math{O(@log n)}
@item @code{gl_oset_iterator}
@tab @math{O(1)}
@tab @math{O(@log n)}
@item @code{gl_oset_iterator_next}
@tab @math{O(1)}
@tab @math{O(@log n)}
@end multitable

The implementations and the guaranteed average performance for the operations
for the ``map'' data type are:

@multitable @columnfractions 0.4 0.2 0.4
@headitem Operation
@tab ARRAY
@tab LINKEDHASH, HASH
@item @code{gl_map_size}
@tab @math{O(1)}
@tab @math{O(1)}
@item @code{gl_map_get}
@tab @math{O(n)}
@tab @math{O(1)}
@item @code{gl_map_put}
@tab @math{O(n)}
@tab @math{O(1)}
@item @code{gl_map_remove}
@tab @math{O(n)}
@tab @math{O(1)}
@item @code{gl_map_search}
@tab @math{O(n)}
@tab @math{O(1)}
@item @code{gl_map_iterator}
@tab @math{O(1)}
@tab @math{O(1)}
@item @code{gl_map_iterator_next}
@tab @math{O(1)}
@tab @math{O(1)}
@end multitable

The implementations and the guaranteed average performance for the operations
for the ``ordered map'' data type are:

@multitable @columnfractions 0.5 0.25 0.25
@headitem Operation
@tab ARRAY
@tab TREE
@item @code{gl_omap_size}
@tab @math{O(1)}
@tab @math{O(1)}
@item @code{gl_omap_get}
@tab @math{O(@log n)}
@tab @math{O(@log n)}
@item @code{gl_omap_put}
@tab @math{O(n)}
@tab @math{O(@log n)}
@item @code{gl_omap_remove}
@tab @math{O(n)}
@tab @math{O(@log n)}
@item @code{gl_omap_search}
@tab @math{O(@log n)}
@tab @math{O(@log n)}
@item @code{gl_omap_search_atleast}
@tab @math{O(@log n)}
@tab @math{O(@log n)}
@item @code{gl_omap_iterator}
@tab @math{O(1)}
@tab @math{O(@log n)}
@item @code{gl_omap_iterator_next}
@tab @math{O(1)}
@tab @math{O(@log n)}
@end multitable

For C++, Gnulib provides a C++ template class for each of these container data types.

@multitable @columnfractions .30 .20 .25 .25
@headitem Data type
@tab C++ class
@tab Module
@tab Include file
@item Sequential list
@tab @code{gl_List}
@tab @code{list-c++}
@tab @code{"gl_list.hh"}
@item Set
@tab @code{gl_Set}
@tab @code{set-c++}
@tab @code{"gl_set.hh"}
@item Ordered set
@tab @code{gl_OSet}
@tab @code{oset-c++}
@tab @code{"gl_oset.hh"}
@item Map
@tab @code{gl_Map}
@tab @code{map-c++}
@tab @code{"gl_map.hh"}
@item Ordered map
@tab @code{gl_OMap}
@tab @code{omap-c++}
@tab @code{"gl_omap.hh"}
@end multitable

@ifnottex
@unmacro log
@end ifnottex
@ifhtml
@unmacro mathopsup
@end ifhtml
@ifinfo
@unmacro mathopsup
@end ifinfo
