Useless Containers Library

Useless Containers Library

This document describes version 2.0d2 of Useless Containers Library, a C language library implementing a set of containers.

The package is distributed under the terms of the GNU General Public License (GPL).

The latest release can be downloaded from:

development takes place at:

and as backup at:

Copyright © 2001-2010, 2013, 2015 by Marco Maggi marco.maggi-ipsu@poste.it

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with Invariant Sections being “GNU Free Documentation License” and “GNU General Public License”, no Front–Cover Texts, and no Back–Cover Texts. A copy of the license is included in the section entitled “GNU Free Documentation License”.

• overview: Overview of the library.
• version: Version functions.
• memory: Memory allocation.
• typedefs: Data types you have to know.
• containers: The data structures.
• iterators: Container iteration.
• misc: Miscellaneous functions.

Appendices

• Package License: GNU General Public License.
• Documentation License: GNU Free Documentation License.
• references: Bibliography and references.
• concept index: An entry for each concept.
• function index: An entry for each function.
• type index: An entry for each type.
• variable index: An entry for each variable.

1 Overview of the library

This container library may be thought of as “low level”. Methods are provided to handle collected data, but no container can be used without wrapping it in a module whose functions “know” how to deal with the type of collected data.

Useless Containers Library installs the single header file ucl.h. All the function names in the API are prefixed with ucl_; all the constant names are prefixed with UCL_; all the type names are prefixed with ucl_ and suffixed with _t.

There is no error reporting system: it is our responsibility to validate function's arguments using the appropriate UCL functions. With the single exception of the vector module: UCL does no memory allocation.

The library is developed and tested under the GNU+Linux system and officially it supports only the GNU infrastructure: requires the GNU C library and compiles fine with the GNU C compiler (-std=c99 -pedantic switches).

The library makes use of inline functions and it is designed to be used only by C libraries and programs; it is probably impossible to interface it with other languages, unless through a C language wrapper library.

• overview linking: Linking code with the library.
• overview error: Error handling.
• overview size: Structures size.
• overview const: Constification.

1.1 Linking code with the library

This package installs a data file for pkg-config, so when searching for the installed library with the GNU Autotools, we can:

• Install the file pkg.m4 from /usr/share/aclocal into the source tree of the package, for example under meta/autoconf/.
• Include pkg.m4 in the template by adding the following line to acinclude.m4:

            m4_include(meta/autoconf/pkg.m4)
  

• Just add the following macro use to configure.ac:

            PKG_CHECK_MODULES([UCL],[ucl >= 2.0])
  

  which will set the variables UCL_LIBS and UCL_CFLAGS.

Alternatively we can use the raw GNU Autoconf macros:

     AC_CHECK_LIB([ucl],[cct_version_string],,
       [AC_MSG_FAILURE([test for UCL library failed])])
     AC_CHECK_HEADERS([ucl.h],,
       [AC_MSG_FAILURE([test for UCL header failed])])

1.2 Error handling

The design of methods tries to be the one that maximises the number of functions that cannot fail. This sometimes leads to “strange” or “dangerous” methods: functions that will cause the application to crash if an argument is incorrect. But, in these cases, the library provides a function to test the argument separately: to assert the precondition.

For example: if a vector index is out of range, we have to make sure not to hand it to an insertion/extraction method; we have to test it first and make use of it only if the test result is good.

1.3 Structures size

Under the examples directory of the source tree there is a small program that links to the library and prints the size of the UCL data structures; it can be built and run with the examples makefile rule. On a i686-pc-linux-gnu the output is:

     Size of common data types:
     
     char            1 :)
     void *          4
     int             4
     short int       2
     long int        4
     long long       8
     float           4
     double          8
     long double     12
     size_t          4
     ptrdiff_t       4
     ucl_value_t     4
     
     Limits:
     
     short int (SHRT_MIN, SHRT_MAX)  -32768 32767
     integer (INT_MIN, INT_MAX)      -2147483648 2147483647
     unsigned short int (USHRT_MAX)  65535
     unsigned (UINT_MAX)             4294967295
     
     Size of UCL structures:
     
     ucl_circular_t       16
     ucl_hash_table_t     36
     ucl_heap_t           32
     ucl_iterator_t       20
     ucl_map_t            28
     ucl_vector_t         48
     
     Size of UCL link structures:
     
     ucl_node_tag_t       16
     ucl_graph_node_tag_t 24
     ucl_graph_link_tag_t 28

1.4 Constification

This library has the need to write functions, conceptually, like this one:

     void data_type_t *
     the_function (data_type_t * p)
     {
       return p;
     }

that is: functions that do not modify the arguments, but whose return value must be modifiable. To write them like this:

     void data_type_t *
     the_function (const data_type_t * p)
     {
       return p;
     }

would be useful because:

1. it makes clear to the user that the data referenced by p is not modified;
2. causes the compiler to raise an error if we attempt to modify the data;

but a warning is issued because the return statement discards the const qualifier.

The adopted solution is to avoid the -Wcast-qual flag of the GNU C compiler, which is responsible to issue a warning if we discard a qualifier with a cast; so the following implementation does not raise warnings:

     void data_type_t *
     the_function (const data_type_t * p)
     {
       return (data_type_t *)p;
     }

It is not beautiful. But the ugliness is only in the UCL code, the user does not see it.

2 Version functions

The installed libraries follow version numbering as established by the GNU Autotools. For an explanation of interface numbers as managed by GNU Libtool See interface.

3 Memory allocation

UCL tries to avoid as much as possible the responsibility to allocate and release memory. Dynamic structures based on trees or linked lists do not call any memory allocation function: the responsibility to allocate UCL data structures is delegated to the user's code.

This makes the library a little more complex to use, but it also makes the code simpler by reducing the error cases that have to be dealt with. Also, user's code can implement a custom allocator and feed memory blocks to UCL's functions. This behaviour can be leveraged to improve performance, because the UCL makes use of a lot of little data structures.

When needed: the library makes use of a default allocator that reverts to the standard malloc(), realloc() and free() functions.

• memory typedefs: Allocator data types.
• memory functions: The default allocator.
• memory blocks: Handling blocks of memory.
• memory ascii: Handling ASCII strings.
• memory macros: Miscellaneous macros.

3.1 Data types

The following API has two main purposes:

1. to implement the classic alloc, realloc and free operations;
2. to define an allocator data structure that is small enough to be used directly as function argument (that is: passed by value).

Example of new memory block allocation:

     ucl_memory_allocator_t allocator;
     void * p = NULL;
     
     allocator.alloc(allocator.data, &p, 4096);

example of memory block reallocation:

     ucl_memory_allocator_t allocator;
     void * p = ...;
     
     allocator.alloc(allocator.data, &p, 4096);

example of memory release:

     ucl_memory_allocator_t allocator;
     void * p = ...;
     
     allocator.alloc(allocator.data, &p, 0);

3.2 Public interface

3.3 Memory blocks

This module offers a set of functions to handle memory blocks; its purpose is to provide a small data structure (ucl_block_t) which can be used directly as argument to function and return value from function, instead of the couple: pointer to memory block, block length in bytes. All the functions are defined in the header ucl.h and declared as __inline__.

Memory allocation

Setting

Inspection

Memory operations

Block operations

3.4 Handling ASCII strings

This module offers a set of functions to handle ASCII coded, zero terminated strings; its purpose is to provide a small data structure (ucl_ascii_t) which can be used directly as argument to function and return value from function, instead of the couple: pointer to memory block, block length in bytes. All the functions are defined in the header ucl.h and declared as __inline__.

3.5 Miscellaneous macros

3.5.1 Structures

4 Data types you have to know

The types of container structures and links/nodes are described in the sections dedicated to containers. Here common data types are described.

• typedefs value: Collected values and others.
• typedefs ranges: Range selectors.
• typedefs compar: Comparison functions.
• typedefs hash: Hash functions.
• typedefs callback: Callback functions.
• typedefs nodes: Wrapping node structures.

4.1 Collected values and others

Temporary linked lists

Let's say that we want to preallocate a set of structures to be used with the UCL, for example: ucl_list_link_t, the structure representing a node in the UCL's doubly linked list. We allocate them with code like:

     #define NUMBER_OF_PREALLOCATED_STRUCTS          4096
     ucl_memory_allocator    allocator;
     ucl_list_link_t *       link_p;
     
     for (size_t i=0; i<NUMBER_OF_PREALLOCATED_STRUCTS; ++i) {
       link_p = NULL;
       allocator.alloc(allocator.data, &link_p, sizeof(ucl_list_link_t));
       /* here we have to put the links somewhere */
     }

it can be convenient to put the links in a linked list and extract them at usage time. We do not want to use the ucl_list_t container, because it is overkill for this application, so we can use the following special type.

With it the preallocation code looks like this:

     #define NUMBER_OF_PREALLOCATED_STRUCTS          4096
     ucl_memory_allocator    allocator;
     ucl_link_t *            link_list_p = NULL;
     
     
     {
       ucl_link_t *          link_p;
     
     
       for (size_t i=0; i<NUMBER_OF_PREALLOCATED_STRUCTS; ++i)
         {
           link_p = NULL;
           allocator.alloc(allocator.data, &link_p, sizeof(ucl_list_link_t));
           if (link_list_p)
             {
               link_p->next_p = link_list_p;
               link_list_p    = link_p;
             }
           else
             {
               link_list_p = link_p;
               link_list_p->next_p = NULL; /* just to be sure */
             }
         }
     }

to extract the links we do:

     ucl_link_t *            link_p;
     ucl_link_t *            link_list_p;
     ucl_list_link_t *       list_link_p;
     
     ...
     
     if (link_list_p)
       {
         link_p = link_list_p;
         link_list_p = link_p->next_p;
         list_link_p = (ucl_list_link_t *)link_p;
         /* here we can use 'list_link_p' */
       }
     else
       {
         /* no more preallocated links */
       }

and to put them back:

     ucl_link_t *            link_p;
     ucl_link_t *            link_list_p;
     
     ...
     
     if (link_list_p)
       {
         link_p->next_p = link_list_p;
         link_list_p    = link_p;
       }
     else
       {
         link_list_p = link_p;
         link_list_p->next_p = NULL;
       }

With better memory allocation:

     #define NUMBER_OF_PREALLOCATED_STRUCTS          4096
     #define SIZE_OF_PREALLOCATED_MEMORY             \
       (NUMBER_OF_PREALLOCATED_STRUCTS * sizeof(ucl_list_link_t))
     
     ucl_memory_allocator    allocator;
     void *                  preallocated_links = NULL;
     ucl_link_t *            link_list_p;
     
     
     /* let's assume that this allocator initialises the
        block to zero bytes */
     allocator.alloc(allocator.data, &preallocated_links,
                     SIZE_OF_PREALLOCATED_MEMORY);
     
     {
       ucl_link_t *          link_p;
     
     
       link_p = link_list_p = preallocated_links;
       for (size_t i=0; i<NUMBER_OF_PREALLOCATED_STRUCTS-1; ++i)
         {
           link_p->next_p = link_p + sizeof(ucl_list_link_t);
           link_p = link_p->next_p;
         }
     }

4.2 Range selectors

All these macros accept as range arguments the name of a range structure, not the name of a pointer to the structure. Range stuff is written in macros, not __inline__ functions, so that they work with all the type structures defined below.

4.3 Comparison functions

Example:

     ucl_comparison_fun_t    intcmp;
     ucl_comparison_t        compar = {
       .data = NULL, .func = intcmp
     };
     ucl_value_t             a = ...;
     ucl_value_t             b = ...;
     int                     result;
     
     result = compar.func(compar.data, a, b);

4.4 Hash functions

4.5 Callback functions

Custom callback application

The UCL does not support any error reporting mechanism; this means that ucl_callback_apply() does not expect the callback to fail. To avoid problems all the UCL modules that need to apply a callback to arguments, do so by invoking a customisable function and are written in such a way that if the callback raises an exception nothing bad happens. The following API handles this.

4.6 Wrapping node structures

The following is a usage example:

     typedef struct link_tag_t {
       ucl_node_tag_t        node;
       ucl_value_t           key;
     } link_tag_t;
     
     typedef link_tag_t *        link_t;
     
     static ucl_value_t
     link_key (ucl_value_t context UCL_UNUSED, void * L_)
     {
       link_t    L = L_;
       return L->key;
     }
     
     static const ucl_node_getkey_t getkey = {
       .data = { .pointer = NULL },
       .func = link_key
     };

we can use the key extractor directly like this:

     link_t          L;
     ucl_value_t     K;
     
     K = getkey.func(getkey.data, L);

5 The data structures

• btree: The binary tree structure.
• tree: The tree structure.
• circular: The circular list structure.
• graph: The graph structure.
• hash: The hash table structure.
• heap: The heap structure.
• list: The linked list structure.
• map: The map structure.
• vector: The vector structure.

5.1 The binary tree container

• btree typedefs: Implementation and type definitions.
• btree examples: Usage examples.
• btree creation: Building btree hierarchies.
• btree inspection: Accessing nodes.
• btree removing: Removing elements.
• btree find: Finding values.
• btree swap: Swapping nodes.
• btree visitors: Finding nodes.
• btree iteration: Iterations in a btree hierarchy.
• btree bst: Routines for raw binary search trees.
• btree avl: Routines for AVL trees.

5.1.1 Implementation and type definitions

This section presents an implementation of binary tree; the container is a chain of structures:

       ------  bro   ------
      | node |----->| node |
      |   1  |<-----|   2  |
       ------  dad   ------
        | ^
     son| |dad
        v |
       ------
      | node |
      |   3  |
       ------

each node data structure is a collection of pointers and of metadata fields whose usage is reserved by UCL; there's no data field.

5.1.2 Usage examples

Let's say we want to organise a set of characters in a binary tree; we define the tree node type and allocation functions like these:

     typedef struct node_tag_t {
       ucl_node_tag_t  node;
       char            c;
     } node_tag_t;
     
     typedef node_tag_t *    node_t;
     
     ucl_memory_allocator_t  A = {
       .data  = NULL,
       .alloc = ucl_memory_alloc
     };
     
     node_t
     node_make (char c)
     {
       node_t        p = NULL;
     
       A.alloc(A.data, &p, sizeof(node_tag_t));
       p->c = c;
       return p;
     }
     void
     node_final (node_t p)
     {
       A.alloc(A.data, &p, 0);
     }
     __inline__ void
     node_clean (node_t p)
     {
       ucl_struct_clean(p, node_tag_t);
     }

and we remember that the built in UCL allocation function (ucl_memory_alloc()) sets to zero all the bytes of newly allocated blocks.

We define the getter/setter functions in “generic” form, like these:

     __inline__ void
     node_set (node_t p, void * data)
     {
       p->c = *((char *)data);
     }
     __inline__ void *
     node_get (node_t p)
     {
       return &(p->c);
     }

Now if we want the following hierarchy:

            ---  bro  ---
           | a |---->| c |
            ---       ---
             |         |
         son v     son v
            ---       ---
           | b |     | d |
            ---       ---

we do it like this, taking advantage of the fact that the binary tree functions accept void * values as arguments:

     node_t  a, b, c, d;
     
     a = node_make('a');
     b = node_make('b');
     c = node_make('c');
     d = node_make('d');
     
     ucl_btree_dadson(a, b);
     ucl_btree_dadbro(a, c);
     ucl_btree_dadson(c, d);

the following expressions are true:

     NULL == ucl_btree_getdad(a)
     a    == ucl_btree_getdad(b)
     a    == ucl_btree_getdad(c)
     c    == ucl_btree_getdad(d)
     
     c    == ucl_btree_getbro(a)
     NULL == ucl_btree_getbro(b)
     NULL == ucl_btree_getbro(c)
     NULL == ucl_btree_getbro(d)
     
     b    == ucl_btree_getson(a)
     NULL == ucl_btree_getson(b)
     d    == ucl_btree_getson(c)
     NULL == ucl_btree_getson(d)

5.1.3 Building btrees hierarchies

The correct way of building binary trees is to allocate node structures with a function that cleans them up, like calloc(), then use the following functions to initialise the fields. If a structure is recycled, we must reset its fields to zero first.

All the following functions accept void * values as arguments: internally these pointers are cast to ucl_node_t.

Single link setters

Double link setters

Triple link setters

5.1.4 Accessing nodes

All the following functions accept void * values as arguments and return void * values; internally these pointers are cast to ucl_node_t.

5.1.5 Removing elements

It's a matter of setting pointers to NULL; care must be taken not to loose references to subtrees.

All the following functions accept void * values as arguments and return void * values; internally these pointers are cast to ucl_node_t.

5.1.6 Finding values

The purpose of a binary tree is to organise values in a hierarchy; the functions described in this section can be used to find values.

The following function accepts void * values as arguments and return a void * value; internally these pointers are cast to ucl_node_t.

5.1.7 Swapping nodes

The following function accepts void * values as arguments and return a void * value; internally these pointers are cast to ucl_node_t.

5.1.8 Finding nodes

All the following functions accept void * values as arguments and return void * values; internally these pointers are cast to ucl_node_t.

5.1.9 Iterations in a btree hierarchy

• btree inorder iteration: Inorder iteration.
• btree preorder iteration: Preorder iteration.
• btree postorder iteration: Postorder iteration.
• btree breadth first: Breadth first iteration.

5.1.9.1 Inorder iteration

Forward inorder iteration: visit all the nodes from the leftmost to the rightmost. Backward inorder iteration: visit all the nodes from the rightmost to the leftmost. Example: given the tree:

     5-------10----12
     |        |     |
     1--3--4  7--9 11
        |     |  |
        2     6  8

the inorder iteration is:

     forward:   1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12
     backward: 12, 11, 10,  9,  8,  7,  6,  5,  4,  3,  2,  1

All the following functions accept void * values as arguments and return void * values; internally these pointers are cast to ucl_node_t.

Examples of forward iteration

To perform a complete forward inorder iteration, we have to start from the leftmost node (0 in the picture above), already visited, and begin from there. Example:

     ucl_node_t   cur = get_the_top_node();
     
     for (cur = ucl_btree_find_leftmost(cur);
          cur;
          cur = ucl_btree_step_inorder(cur));
       {
         do_something_with(cur);
       }

To restrict the iteration to a subtree of a tree or to a range of nodes in a tree, we have to select the first and last nodes and check when the iterator reaches the last.

Example of subtree restriction: does an inorder iteration from the top of a subtree to the rightmost node in the subtree:

     ucl_node_t        cur, end;
     
     cur = get_a_node(...);
     end = ucl_btree_find_rightmost(cur);
     
     for (cur = ucl_btree_find_leftmost(cur);
          cur != end;
          cur = ucl_btree_step_inorder(cur))
       {
         do_something_with(cur);
       }
     
     /* Here "cur == end" and we visit it. */
     do_something_with(cur);

cur can't be NULL because end is in the subtree of the top node; this code will work even when cur == end at the beginning.

Example of range restriction: does an iteration starting from a node (not the leftmost) to the rightmost one:

     ucl_node_t        root, cur, end;
     
     root	= get_a_node();
     end	= ucl_btree_find_rightmost(root);
     
     for (cur = select_first(root, ...);
          cur != end;
          cur = ucl_btree_step_inorder(cur))
       {
         do_something_with(cur);
       }

cur can't be NULL because we selected the first and last nodes in a subtree; this code will work even when root == cur == end at the beginning.

Examples of backward iteration

To perform a complete backward iteration, we have to start from the rightmost node (12 in the picture above), already visited, and begin from there. Example:

     ucl_node_t   cur = get_the_top_node();
     
     for (cur = ucl_btree_find_rightmost(cur);
          cur;
          cur = ucl_btree_step_inorder_backward(cur))
       {
         do_something_with(cur);
       }

To restrict the iteration to a subtree of a tree or to a range of nodes in a tree, we have to select the first and last nodes and check when the iterator reaches the last.

Example of subtree restriction: does an iteration from the rightmost to the leftmost nodes in a subtree:

     ucl_node_t        cur, end;
     
     cur = get_a_node(...);
     end = ucl_btree_find_leftmost(cur);
     
     for (cur = ucl_btree_find_rightmost(cur);
          cur != end;
          cur = ucl_btree_step_inorder_backward(cur))
       {
         do_something_with(cur);
       }
     
     /* Here "cur == end" and we visit it. */
     do_something_with(cur);

cur can't be NULL because end is in the subtree of the top node; this code will work even when cur == end at the beginning.

Example of range restriction:

     ucl_node_t        root, cur, end;
     
     root	= get_a_node();
     end	= ucl_btree_find_leftmost(root);
     
     for (cur = select_first(root, ...);
          cur != end;
          cur = ucl_btree_step_inorder_backward(cur))
       {
         do_something_with(cur);
       }
     
     /* Here "cur == end" and we visit it. */
     do_something_with(cur);

cur can't be NULL since we selected the first and last nodes in a subtree; this code will work even when root == cur == end a the beginning.

5.1.9.2 Preorder iteration

Preorder iteration: visit the current node then the son then the brother. Example:

     5-------10----12
     |        |     |
     1--3--4  7--9 11
        |     |  |
        2     6  8

the preorder iteration is:

     forward:    5,  1,  3,  2,  4, 10,  7,  6,  9,  8, 12, 11
     backward:   5, 10, 12, 11,  7,  9,  8,  6,  1,  3,  4,  2

the forward iteration is a “worm that always turns right”, while the backward iteration is a “worm that always turns left”.

All the following functions accept void * values as arguments and return void * values; internally these pointers are cast to ucl_node_t.

Examples of forward iteration

To perform a complete iteration, we have to start from the top node of the tree (5 in the picture above), already visited, and begin from there. Example:

     ucl_node_t        cur;
     
     for (cur = select_the_top_node();
          cur;
          cur = ucl_btree_step_pre(cur))
       {
         do_something_with(cur);
       }

this works because the top node of a btree has a NULL value in the dad pointer field.

To restrict the iteration to a subtree of a tree: we cannot loop until the function returns NULL, because the top node of a subtree has a non–NULL value in the dad pointer field. With reference to the picture above: we select the top node (number 10) and we visit it; then we step to the next (number 7) and visit it; then we enter the loop until the iterator reaches the top node (number 10 again).

Example:

     ucl_node_t        cur, end;
     
     end = cur = get_a_node();
     
     do_something_with(cur);
     for (cur = ucl_btree_step_preorder(cur);
          cur != end;
          cur = ucl_btree_step_preorder(cur))
       {
         do_something_with(cur);
       }

5.1.9.3 Postorder iteration

Postorder iteration: visit the son, then the brother, then the parent node. Example:

     5-------10----12
     |        |     |
     1--3--4  7--9 11
        |     |  |
        2     6  8

the postorder iteration is:

     forward:    2,  4,  3,  1,  6,  8,  9,  7, 11, 12, 10,  5
     backward:  11, 12,  8,  9,  6,  7, 10,  4,  2,  3,  1,  5

All the following functions accept void * values as arguments and return void * values; internally these pointers are cast to ucl_node_t.

Examples of forward iteration

To perform a complete iteration, we have to select the deepest leftmost son in the tree (2 in the example) and begin from there. Example:

     ucl_node_t        cur;
     
     cur = get_a_node();
     for (cur = ucl_btree_find_deepest_son(cur);
          cur != NULL;
          cur = ucl_btree_step_postorder(cur));
       {
         do_something_with(cur);
       }

To restrict the iteration to a subtree of a tree, we have to check when the iterator reaches the top node. Example:

To restrict the iteration to a subtree of a tree: we cannot loop until the function returns NULL, because the top node of a subtree has a non–NULL value in the parent pointer field. With reference to the tree in the picture above: we select the top node (number 10); then we move to the deepest son (number 6) and we visit it; then we enter the loop until the iterator reaches the top node (number 10 again).

Example:

     ucl_node_t        cur, end;
     
     cur = end = get_a_node();
     
     for (cur = ucl_btree_find_deepest_son(cur);
          cur != end;
          cur = ucl_btree_step_postorder(cur));
       {
         do_something_with(cur);
       }
     
     /* Here "cur == end" and we visit it. */
     do_something_with(cur);

cur can't be null in the loop.

5.1.9.4 Breadth first iteration

Breadth first iteration: visit the tree level by level. Example:

     5-------10----12
     |        |     |
     1--3--4  7--9 11
        |     |  |
        2     6  8

the order of the forward iteration is: 5, 1, 10, 3, 7, 12, 2, 4, 6, 9, 11, 8. To do it we need a moving cursor that always “turns right” keeping the count of the level. The order of the backward iteration is: 5, 10, 1, 12, 7, 3, 11, 9, 6, 4, 2, 8.

All the following functions accept void * values as arguments and return void * values; internally these pointers are cast to ucl_node_t.

Examples of forward iteration

To perform a complete iteration, we just call the function until it returns NULL. Example:

     ucl_node_t cur;
     
     for (cur = get_the_top_node();
          cur != NULL;
          cur = ucl_btree_step_levelorder(cur));
       {
         do_something_with(cur);
       }

Examples of backward iteration

To perform a complete iteration, we just call the function until it returns NULL. Example:

     ucl_node_t cur;
     
     for (cur = get_the_top_node();
          cur != NULL;
          cur = ucl_btree_step_levelorder_backward(cur));
       {
         do_something_with(cur);
       }

5.1.10 Routines for raw binary search trees

The following routines can be used in the implementation of raw binary search trees (BST); they are included in UCL only for completeness, because we should use balanced trees not raw ones.

All the following functions accept void * values as arguments and return values; internally these pointers are cast to ucl_node_t.

5.1.11 Routines for AVL trees

The following routines are used in the implementation of the AVL binary search tree; they are not meant to be used directly. map for the UCL implementation of AVL search trees.

All the following functions accept void * values as arguments and return values; internally these pointers are cast to ucl_node_t.

The meta field of the ucl_node_tag_t structure is used to store an AVL status integer which is: -1 when the son subtree is higher than the bro subtree; +1 when the bro subtree is higher than the son subtree; 0 when the son subtree and the bro subtree have equal depth. In a balanced AVL tree the difference in depth between a son subtree and a bro subtree is always at most 1; so we can say that the AVL status is the bro's subtree depth minus the son's subtree depth, such difference is called balance factor.

5.2 The tree structure

• tree implementation: How it's done.
• tree creation: Creating a tree hierarchy.
• tree insertion: Inserting nodes into a tree.
• tree testing: Testing relationships between nodes.
• tree relatives: Accessing or setting the relatives of a node.
• tree removing: Removing elements from a tree.
• tree iterators: Traversing a tree.

5.2.1 How it's done

The implementation is a binary tree with nodes of type ucl_node_t; the only difference between the btree and the tree is the interpretation of the bro nodes. This means that all the functions in the btree module can be used on a tree, and the tree module adds functions to establish the interpretation policy.

In the following picture: the nodes B, C, D and E are all “children” of the node A; the node A is the father of the nodes B, C, D and E. So in a tree a node can have and indefinite number of children.

        -----
       |  A  |
        -----
         ^ |son
      dad| v
        -----  bro   -----  bro   -----  bro   -----  bro
       |  B  |----->|  C  |----->|  D  |----->|  E  |----->NULL
        ----- <----- ----- <----- ----- <----- -----
         ^ |   dad    ^ |   dad          dad
      dad| vson    dad| vson
        -----        -----
       |  F  |      |  G  |
        -----        -----

Pointers condition meaning:

node.dad == NULL

the node is the root node of a tree;

node.bro == NULL

the node has no brothers, so it's the last brother between the children of its father;

node.son == NULL

the node has no children;

A.dad == B && B.son == A

A is the first between the children of node B;

A.dad == B && B.bro == A

A and B are brothers, and children of the same parent node.

5.2.2 Creating a tree hierarchy

The node structures must be allocated by the client code and all the bytes set to zero before usage. The btree functions can be used directly, but UCL provides aliases for them when they must be used for a tree.

All the following functions accept void * values as arguments: internally these pointers are cast ucl_node_t.

Single link setters

Double link setters

5.2.3 Inserting nodes into a tree

The following functions are used to insert subtrees in a tree. None of the nodes in the target tree are detached. The links in the new subtrees that are not interested by the relations in these functions, are left untouched.

All the following functions accept void * values as arguments: internally these pointers are cast ucl_node_t.

Example of dad insertion:

     ucl_tree_insert_dad( 1, A )
     
     0               D         0
     |               |         |
     1--2--3--4  +   A--C  =   A--C
     |  |            |         |
     5  6            B         1--2--3--4
                               |  |
                               5  6

the D and B nodes are detached and will be lost if we don't keep a reference to them.

Example of son insertion:

     ucl_tree_insert_son( 0, A )
     
     0               D         0
     |               |         |
     1--2--3--4  +   A--C  =   1--2--3--4--A--C
     |  |            |         |  |        |
     5  6            B         5  6        B

the node D is detached and will be lost if we don't keep a reference to it.

Example of prev node insertion:

     ucl_tree_insert_prev( 2, A )
     
     0               D         0
     |               |         |
     1--2--3--4  +   A--C  =   1--A--2--3--4
     |  |            |         |  |  |
     5  6            B         5  B  6

the D and C nodes are detached and will be lost if we don't keep a reference to them.

Example of next brother insertion:

     ucl_tree_insert_next( 2, A )
     
     0               D         0
     |               |         |
     1--2--3--4  +   A--C  =   1--2--A--3--4
     |  |            |         |  |
     5  6            B         5  6

the D, B and C nodes are detached and will be lost if we don't keep a reference to them.

5.2.4 Testing relationships between nodes

All the following functions accept void * values as arguments: internally these pointers are cast to ucl_node_t.

5.2.5 Accessing or setting the relatives of a node

All the following functions accept void * values as arguments: internally these pointers are cast to ucl_node_t.

5.2.6 Removing elements from a tree

These functions will extract a node from a tree, returning a pointer to the extracted node. All the following functions accept void * values as arguments and return void * values: internally these pointers are cast to ucl_node_t.

5.2.7 Traversing a tree

For the tree iterators, the return value of ucl_iterator_ptr() is a pointer to the current node. All the following functions accept void * values as arguments: internally these pointers are cast to ucl_node_t.

5.3 The heap structure

The heap container allows us to collect a bunch of values and extract them sorted, from the lesser to the greater, according to a custom comparison function. The UCL heap is implemented as a binary tree, with nodes of type ucl_node_tag_t; the current implementation is probably inefficient, especially because of the cost of finding the next node under which append new nodes; but even without that, it would not be an efficient implementation anyway.

• heap intro: How it is done.
• heap types: Heap type definitions.
• heap creation: Creating and destroying heaps.
• heap insertion: Adding elements to a heaps.
• heap deletion: Removing elements from a heaps.
• heap ops: Various operations on a heaps.

5.3.1 How it is done

The heap is implemented as binary tree in which we keep track of the root node and of the “next dad” node; new nodes are appended as children of the next dad, first as son then as bro; if a new node has key lesser than its dad we raise it in the tree.

Let's see an example of heap construction. Let's say the heap already has ‘5’ as root node; being the only one, the root node is also the next dad (marked with ‘n’ in the pictures). Let's append ‘8’ as son of the next dad:

     n5
      |
      8

now let's append ‘10’ as bro of next dad; the next dad becomes full so we do a breadth first step from ‘5’ to update it:

     n5--10       5--10
      |      =>   |
      8          n8

now let's append ‘3’ as son of next dad, then raise it in the tree while it is lesser than its dad:

      5--10       5--10       3--10
      |           |           |
     n8      =>  n3      =>  n5
      |           |           |
      3           8           8

now let's append ‘4’ as bro of next dad, then raise it in the tree while it is lesser than its dad; finally, since the next dad has become full, we do a breadth first step from ‘4’ to update it:

      3--10       3--10      3--n10
      |           |          |
     n5--4   =>  n4--5   =>  4--5
      |           |          |
      8           8          8

we understand how to add ‘12’:

     3--n10      3----n10
     |           |     |
     4--5    =>  4--5  12
     |           |
     8           8

and how to add ‘14’ updating the next dad with a breadth first step from ‘10’:

     3----n10--14      3-----10--14
     |     |           |     |
     4--5  12      =>  4--5  12
     |                 |
     8                n8

further nodes will be appended to ‘8’.

Let's see some examples of node extraction. Extracting a node from the heap means to extract its root, which is the lesser one; we replace it with the lesser among its children, then recursively descend the tree always replacing with the lesser. So first we extract ‘3’:

      3-----10--14      4-----10--14      4-----10--14
      |     |           |     |           |     |
      4--5  12      =>  *--5  12      =>  5     12
      |                 |                 |
     n8                n8                n8

then we extract ‘4’:

      4-----10--14      5-----10--14      5-----10--14
      |     |           |     |           |     |
      5     12      =>  *     12      => n8     12
      |                 |
     n8                n8

and so on.

5.3.2 Heap type definitions

The UCL heap container collects nodes of type ucl_node_tag_t, which hold no custom data; we have to at least associate a key to each node, doing something like this:

     typedef struct link_tag_t {
       ucl_node_tag_t        node;
       ucl_value_t           key;
     } link_tag_t;
     
     typedef link_tag_t *        link_t;
     
     static ucl_value_t
     link_key (ucl_value_t context UCL_UNUSED, void * L_)
     {
       link_t    L = L_;
       return L->key;
     }
     
     static const ucl_node_getkey_t getkey = {
       .data = { .pointer = NULL },
       .func = link_key
     };

and then use getkey as last argument to ucl_heap_initialise(); we can use the key extractor directly like this:

     link_t          L;
     ucl_value_t     K;
     
     K = getkey.func(getkey.data, L);

5.3.3 Creating and destroying heap

5.3.4 Adding elements to a heap

5.3.5 Removing elements from a heap

5.3.6 Various operations on a heap

5.4 The circular list

The circular container provides a circular doubly linked list; it is implemented as a chain of ucl_node_t structures; a pointer to the current position is stored in a base structure. The current position marker can be moved forward and backward as a cursor.

The handling of list links is derived from the handling of elements in the TCL (Tool Command Language) hash table by John Ousterhout and others (http://www.tcl.tk for more about TCL).

• circular creation: Creating and destroying circulars.
• circular adding: Adding elements to a circular.
• circular removing: Removing elements from a circular.
• circular moving: Moving the cursor.
• circular search: Searching elements.
• circular ops: Various operations on a circular.

5.4.1 Creating and destroying circulars

To extract all the links from a circular list, we can do:

     ucl_circular_t  circ;
     ucl_node_t      link;
     ucl_value_t     val;
     
     while (ucl_circular_size(circ))
       {
         link = ucl_circular_extract(circ);
         /* insert here the code to destroy the value */
         /* insert here the code to free the link memory */
       }

if the value needs no destructor and we are using a memory allocator as implemented by UCL, we can do:

     ucl_memory_allocator_t  A;
     ucl_circular_t  circ;
     ucl_node_t      link;
     
     while (ucl_circular_size(circ))
       {
         link = ucl_circular_extract(circ);
         A.alloc(A.data, &link, 0);
       }

5.4.2 Adding elements to a circular

Example of link insertion (the link has no value):

     ucl_memory_allocator_t  A;
     ucl_circular_t  circ;
     ucl_node_t      link = NULL;
     
     A.alloc(A.data, &link, sizeof(ucl_node_tag_t));
     ucl_circular_insert(circ, link);

5.4.3 Removing elements from a circular

Example of link deletion and memory release:

     ucl_memory_allocator_t  A;
     ucl_circular_t  circ;
     ucl_node_t      link;
     
     link = ucl_circular_extract(circ);
     if (NULL != link)
       A.alloc(A.data, &link, 0);

5.4.4 Moving the cursor

5.4.5 Searching elements

5.4.6 Various operations on a circular

5.5 The graph structure

A UCL graph is a network of (not so) little data structures; the elements of the graph are nodes and links.

• graph overview: How it's done.
• graph types: Graph type definitions.
• graph insert: Inserting links and nodes.
• graph extract: Extracting links and nodes.
• graph merge: Merging links.
• graph value: Accessing values.
• graph link iter: Link iterators.
• graph ops: Various operations on a graph.
• graph dfs: Depth first search.

5.5.1 How it's done

UCL does not enforce the use of a container to collect graph node structures: it is responsibility of the user to put nodes somewhere. For convenience: the node structure has a “next node” field that allows us to put nodes into a simply linked list, but it is not mandatory to use it.

Each node references two doubly linked lists of links: one for outgoing links and one for incoming links.

                      ------
         NULL  ------| node |-----  NULL
           ^  |       ------      |  ^
           |  v                   v  |
      -----------               ------------
     | in link 0 |             | out link 0 |
      -----------               ------------
          |^                         |^
          v|                         v|
      -----------               ------------
     | in link 1 |             | out link 1 |
      -----------               ------------
          |^                         |^
          v|                         v|
      -----------               ------------
     | in link 2 |             | out link 2 |
      -----------               ------------
          |                          |
          v                          v
        NULL                        NULL

Each link has references of both the source and destination nodes and is part of two doubly linked lists: one of outgoing links of the source node, one of incoming links of the destination node.

         ------------------          -----------------
        | prev output link |        | prev input link |
         ------------------          -----------------
                        |^            ^|
                        ||            ||
                        | ---      --- |
                         --- |    | ---
                            ||    ||
                            v|    |v
      -------------       ------------       -----------
     | source node |<----|    link    |---->| dest node |
      -------------       ------------       -----------
                            |^    ^|
                            ||    ||
                         --- |    | ---
                        | ---      --- |
                        ||            ||
                        v|            |v
         ------------------          -----------------
        | next output link |        | next input link |
         ------------------          -----------------

5.5.2 Graph type definitions

Both node and link structures should be allocated using an equivalent of calloc(), or reset to zero before being inserted in a graph.

5.5.3 Inserting links and nodes

5.5.4 Extracting links and nodes

To erase a node from a graph we have to remove all the links between it and the other nodes. To do it in the case of structures allocated with a UCL memory allocator:

     ucl_memory_allocator_t  A;
     ucl_graph_node_t        N;
     ucl_graph_link_t        L;
     
     for (L = ucl_graph_output_link(N); L;
          L = ucl_graph_output_link(N))
       {
         ucl_graph_unlink(L);
         A.alloc(A.data, &L, 0);
       }
     
     for (L = ucl_graph_input_link(N); L;
          L = ucl_graph_input_link(N))
       {
         ucl_graph_unlink(L);
         A.alloc(A.data, &L, 0);
       }
     
     A.alloc(A.data, &N, 0);

5.5.5 Merging links

Merging means to replace two links with one that represents the whole path; before merging the scenario is:

      --------     ---------     --------     ----------     ------
     | source |<--| in link |-->| middle |<--| out link |-->| dest |
     |  node  |    ---------    |  node  |    ----------    | node |
      --------                   --------                    ------

merging can be done upon the input or the output link; after merging upon the input link:

      --------     ---------     ------
     | source |<--| in link |-->| dest |
     |  node  |    ---------    | node |
      --------                   ------

after merging upon the output link:

      --------     ----------     ------
     | source |<--| out link |-->| dest |
     |  node  |    ----------    | node |
      --------                    ------

5.5.6 Accessing values

5.5.7 Link iterators

Finding first and last links

Finding previous and next links

5.5.8 Various operations on a graph

5.5.9 Depth first search

Depth first search (DFS) is an iteration over the nodes of a graph that starts from a selected node and visits a node only once; the result of the iteration is a string of nodes. The iteration is analogous to the preorder iteration in trees (the worm that always turns right in the labyrinth).

The iteration may not touch all the nodes:

• if the graph is not connected: the DFS does not touch all the nodes;
• if the DFS follows the direction of the links and there are nodes with outgoing links only: the DFS does not touch all the nodes.

UCL implements two types of DFS: one that honors the direction of the links; one that does not.

• graph dfs example: DFS example.
• graph dfs types: DFS related type defintions.
• graph dfs api: DFS programming interface.

5.5.9.1 DFS example

Given the following connected graph:

      -- A ---> B ---> C
     |   |      |
     |   |       ------
     |   |             |
     |   |             v
     |    ----> D <--- E
     |          ^
     v          |
     F ---------

we see that we can partition the nodes in two sets:

     one = { A, F }  two = { B, C, E, D }

there are no links going from partition two to partition one; the directed DFS starting at node B is:

     B, C, E, D

nodes in partition one are not touched; while the undirected DFS starting at node B is:

     B, C, E, D, F, A

all the nodes are touched.

We note that:

1. if the number of nodes touched by the directed DFS equals the number of nodes in the graph: the graph is connected;
2. the iteration goes “deep” inside a graph and then steps back in search of new ramifications;
3. if every time the iterator does a step we increment a counter: by saving the values of counter when entering a node and leaving a node, we can infer properties of the graph.

5.5.9.2 DFS related type defintions

The DFS is implemented as a recursive process that puts touched nodes on a stack. The stack is the result of the iteration. A DFS is not reentrant because nodes are marked by setting a field in ucl_graph_node_t structures: while a DFS is performed the graph must be locked for mutual exclusion.

Also, do not modify a graph while a DFS is running: the result is undefined.

5.5.9.3 DFS programming interface

Example:

     ucl_graph_dfs_t         S;
     ucl_vector_t            visited_nodes;
     
     ucl_graph_initialise_dfs_handle(S, visited_nodes);
     {
       ucl_iterator_t          I;
       ucl_graph_node_t *      root;
     
       ucl_graph_dfs_directed(S, root);
       for (ucl_vector_iterator_forward(visited_nodes, I);
            ucl_iterator_more(I); ucl_iterator_next(I))
         {
           ucl_graph_dfs_item_t *  item;
     
           item = ucl_iterator_ptr(I);
           do_something_with(item);
         }
     }
     ucl_graph_dfs_finalise_handle(S);

5.6 The hash table structure

A hash table is a structure that maps keys to values in a way that allows the search operation to be performed with constant time for all the keys.

The hash was inspired by the book on C++ by Bjarne Stroustrup and the hash structure in the TCL (Tool Command Language) source code, by John Ousterhout and others (http://www.tcl.tk/ for more about TCL). However, no code comes from TCL.

• hash intro: How it is done.
• hash types: Hash table types definitions.
• hash creation: Creating and destroying hash tables.
• hash insertion: Adding elements to a hash table.
• hash deletion: Removing elements from a hash table.
• hash ops: Various operations on a hash table.
• hash resizing: Resizing a hash table.
• hash iterator: Visiting elements in the table.
• hash functions: Provided hash function.

5.6.1 How it is done

A UCL vector of pointers is allocated by the constructor; each pointer, called “bucket” in this document, can be NULL (empty bucket) or referencing an entry structure. Entry structures are chained in a linked list.

                 buckets
     
                  ----         -----     -----
                 |  o-+------>|entry|-->|entry|
                 |----|        -----     -----
     empty  .....|NULL|
     buckets  .  |----|        -----
              .  |  o-+------>|entry|
              .  |----|        -----    -----
              .  |  o-+--------------->|entry|
              .  |----|                 -----
               ..|NULL|
                  ----

The UCL way of managing a vector is to allocate a block of memory, with hysteresis, and consider a sub–block of it as “in use”, that is: as holding the collected data. When the hash table is constructed all the slots are marked as used, even when the bucket is set to NULL. Reallocations can cause some of the slots to be unused, but if we never reallocate the vector all the memory is used to hold buckets.

Elements insertion and deletion

When inserting a new entry in the table, the hash function converts the keys to integers in the range [0, number_of_buckets), selecting a bucket; then the bucket is examined:

• if it's NULL, it's set to the entry pointer:

            before the insertion           after the insertion
            
               ----                           ----
              |    |                         |    |
               ----     -----                 ----     -----
              |NULL|   |entry|               |  o-+-->|entry|
               ----     -----                 ----     -----
              |    |                         |    |
               ----                           ----
  

• if it's not NULL, the referenced entry is appended to the new entry and the bucket is set to a pointer to the new entry:

                       ---
             ---   ...|new|               ---
            |   | .    ---               |   |
             ---  v  ---     ---          ---     ---     ---     ---
            | o-+-->|en1|-->|en2|   ->   | o-+-->|new|-->|en1|-->|en2|
             ---     ---     ---          ---     ---     ---     ---
            |   |                        |   |
             ---                          ---
  

It's obvious how the extraction operation works.

If the keys are such that the hash function distributes entries uniformly over all the buckets, the time spent to find an entry is (more or less) constant.

Resizing

Enlarging or restricting the hash table means enlarging or restricting the vector of buckets. This happens with rules similar, but not equal, to the ones for the ucl_vector_t structure; the differences are:

• when enlarging all the allocated slots are marked as used, so each allocated slot becomes a bucket;
• when restricting the number of used slots is artificially reduced by the amount of slots selected with the “step down” parameter of the UCL vector;
• when restricting the number of used slots cannot become smaller than the amount selected by the preprocessor symbol UCL_HASH_MINIMUM_SIZE, which defaults to 13.

Enlarging and restricting changes the number of buckets, so it requires a rehashing of all the entries in the table: this is expensive.

5.6.2 Hash table types definitions

The UCL hash container collects entries of type ucl_node_tag_t, which hold no custom data; we have to at least associate a key to each node, doing something like this:

     typedef struct entry_tag_t {
       ucl_node_tag_t        node;
       ucl_value_t           key;
     } entry_tag_t;
     
     typedef entry_tag_t *        entry_t;
     
     static ucl_value_t
     entry_key (ucl_value_t context UCL_UNUSED, void * L_)
     {
       entry_t    L = L_;
       return L->key;
     }
     
     static const ucl_node_getkey_t getkey = {
       .data = { .pointer = NULL },
       .func = entry_key
     };

and then use getkey as last argument to ucl_hash_initialise(); we can use the key extractor directly like this:

     entry_t         L;
     ucl_value_t     K;
     
     K = getkey.func(getkey.data, L);

5.6.3 Creating and destroying hash tables

The construction of a hash table is split in two steps, to allow custom configuration of the vector of buckets. A simple construction, using the default values, for a table using strings as keys goes like this:

     ucl_vector_config_t C;
     ucl_vector_t        V;
     ucl_hash_table_t    H;
     ucl_node_getkey_t   getkey;
     
     ucl_vector_initialise_config_hash(C);
     ucl_vector_alloc(V, C);
     ucl_hash_initialise(H, V, ucl_compare_string, ucl_hash_string,
                         getkey);

when finalising a hash table we have to release the UCL vector explicitly, but only after having extracted and released all the table entries; when using a UCL memory allocator, it goes like this:

     ucl_memory_allocator_t  A;
     ucl_vector_t            V;
     ucl_hash_table_t        H;
     entry_t                 E;
     
     while ((E = ucl_hash_first(H)))
       {
         ucl_hash_extract(H, E);
         A.alloc(A.data, &E, 0);
       }
     ucl_vector_free(V);

the hash table structure does not need finalisation.

5.6.4 Adding elements to a hash table

5.6.5 Removing elements from a hash table

5.6.6 Various operations on a hash table

5.6.7 Resizing a hash table

At present the hash table is not enlarged automatically. The decision is delegated to the user's code.

5.6.8 Visiting elements in the table

5.6.9 Provided hash function

5.7 The linked list structure

The UCL list is a way of chaining ucl_node_tag_t structures in a doubly linked list; all the functions from the btree and tree modules can be used upon lists.

• list overview: How it is done.
• list cons: Constructing lists.
• list visit: Visiting a list.
• list deletion: Removing elements from a list.
• list ops: Various operations on a list.
• list iteration: Iteration over a list.

5.7.1 How it is done

A UCL list is a chain of ucl_node_tag_t structures in which the bro and dad fields are involved:

                ----  bro   ----  bro   ----  bro
     NULL <----| N1 |----->| N2 |----->| N3 |----> NULL
           dad  ---- <----  ---- <----  ----
                      dad         dad

it is equivalent to a level of brothers in the UCL tree module; the son field can be set to NULL, or used to reference a nested list, or used to reference some other value. The brother of a node is called cdr, the son of a node is called car.

NOTE We use the terms car and cdr to refer to the son and bro of a node, but notice that their meaning in the context of the UCL is different from their meaning in the context of Lisp languages.

Going forwards in a list chain means to follow the bro pointers; going backwards in a list chain means to follow the dad pointers.

5.7.2 Constructing lists

Structures of type ucl_node_tag_t must be allocated and released by the user code. The fields of a node structure must be set to NULL when they are not used as reference for another node.

All the following functions return and accept as arguments void * values; they are internally cast to ucl_node_t.

For example, to build the hierarchy:

      -----    -----    -------
     | one |--| two |--| three |-- NULL
      -----    -----    -------

using the UCL memory allocator:

     ucl_memory_allocator_t  A;
     ucl_node_t              one, two, three;
     
     one   = ucl_malloc(ucl_memory_allocator, UCL_NODE_SIZE);
     two   = ucl_malloc(ucl_memory_allocator, UCL_NODE_SIZE);
     three = ucl_malloc(ucl_memory_allocator, UCL_NODE_SIZE);
     
     ucl_list_set_cdr(one, two);
     ucl_list_set_cdr(two, three);

remember that the UCL default allocator sets to zero every newly allocated block, so the fields in the allocated nodes are automatically set to NULL.

5.7.3 Visiting a list

All the following functions return and accept as arguments void * values; they are internally cast to ucl_node_t. btree typedefs for the meaning of the fields of ucl_node_tag_t.

When using the following operations, it is impossible to distinguish between a NULL representing a legitimate return value and a NULL representing a return from an invalid operation; we have to take care of applying these operations only when they are legitimate.

5.7.4 Removing elements from a list

All the following functions return and accept as arguments void * values; they are internally cast to ucl_node_t. btree typedefs for the meaning of the fields of ucl_node_tag_t.

5.7.5 Various operations on a list

All the following functions return and accept as arguments void * values; they are internally cast to ucl_node_t. btree typedefs for the meaning of the fields of ucl_node_tag_t.

5.7.6 Iteration over a list

Example of forward iteration:

     ucl_node_t        N;
     
     while (N) {
       /* do something with N */
       N = ucl_list_cdr(N);
     }

example of backward iteration:

     ucl_node_t        N;
     
     while (N) {
       /* do something with N */
       N = ucl_list_prev(N);
     }

5.8 The map structure

The map container is an AVL tree; it can be used to implement an associative array.

The map/multimap idea was inspired by the book on C++ by Bjarne Stroustrup and by the STL C++ (Standard Template Library) by Stepanov and Lee.

The handling of nodes is influenced by the handling of elements in the TCL (Tool Command Language) hash table by John Ousterhout and others (http://www.tcl.tk/ for more about TCL).

• map intro: Introduction to operations and implementation.
• map types: Type definitions for map.
• map creation: Creating and destroying maps.
• map insertion: Adding elements to a map.
• map deletion: Removing elements from a map.
• map ops: Various operations on a map.
• map iterators: Iteration over a map.
• map set: Composing map iterators.

5.8.1 Introduction to operations and implementation

Maps are often used as associative arrays, that is: as collections of key/value pairs. The operations we want to do on a map are:

• add a key/value pair (or just a key) to a collection, if the element already exists replace the old value with the new one or add a new key/value pair;
• find a key/value pair with a specified key;
• remove all key/value pairs with a selected key, or the one with a selected value among the ones having the same key;
• traverse the collection of key/value pairs from the lesser key to the greater;
• traverse the collection of key/value pairs from the greater key to the lesser.

Clearly there are two sub–types of map container: the one that allows multiple values to be associated to the same key, and the one that does not. We call the first a multimap and the second a simple map.

5.8.2 Type definitions for map

The UCL map container collects nodes of type ucl_node_tag_t, which hold no custom data; we have to at least associate a key to each node, doing something like this:

     typedef struct link_tag_t {
       ucl_node_tag_t        node;
       ucl_value_t           key;
     } link_tag_t;
     
     typedef link_tag_t *        link_t;
     
     static ucl_value_t
     link_key (ucl_value_t context UCL_UNUSED, void * L_)
     {
       link_t    L = L_;
       return L->key;
     }
     
     static const ucl_node_getkey_t getkey = {
       .data = { .pointer = NULL },
       .func = link_key
     };

and then use getkey as last argument to ucl_map_initialise(); we can use the key extractor directly like this:

     link_t          L;
     ucl_value_t     K;
     
     K = getkey.func(getkey.data, L);

5.8.3 Creating and destroying maps

5.8.4 Adding elements to a map

The following functions accept void * as arguments and return values; internally these pointers are cast to ucl_node_t.

5.8.5 Removing elements from a map

The following functions accept void * as arguments and return values; internally these pointers are cast to ucl_node_t.

5.8.6 Various operations on a map

The following functions accept void * as arguments and return values; internally these pointers are cast to ucl_node_t.

5.8.7 Iteration over a map

The iteration is over the map links: ucl_iterator_ptr() returns a pointer to the current map link.

5.8.8 Composing map iterators

It's possible to compose map iterators to implement set operations: the keys from a map are used as set elements. A set operation is implemented as an iterator that visits one by one the result of the operation itself.

The key values must be of the same data type. That means that the compare function used by both the maps must accept the same type of values and return the same values when called with the same arguments.

For all the set iterators, the arguments are:

ucl_iterator_t it1

pointer to an in–order iterator over set 1, already initialised;

ucl_iterator_t it2

pointer to an in–order iterator over set 2, already initialised;

ucl_iterator_t iter

pointer to the set iterator structure.

The input map iterators must be of in–order type: if the sequences are visited from the lesser to the greater key, the minimum amount of key comparison is performed.

If the sequences are not visited with the in–order iterator, the result is not defined.

The set iterators are used in the same fashion of all the other iterators in the UCL (iterators). The value retrieved with ucl_iterator_ptr() is the pointer to the referenced map link.

Example:

     Sequence 1: 0 1 2 3 4 5 6
     Sequence 2: 4 5 6 7 8 9
     Union: 0 1 2 3 4 4 5 5 6 6 7 8 9
     Intersection: 4 5 6
     Complementary intersection: 0 1 2 3 7 8 9
     Subtraction: 0 1 2 3

5.9 The vector structure

The vector container is an implementation of array, with hysteresis in memory allocation.

NOTE This module was inspired by the book on C++ by Bjarne Stroustrup and by the STL C++ (Standard Template Library).

NOTE In the following documentation, when describing valid values for vector indexes, we denote a range of values with [min, max), where [ means inclusive bound and ( means exclusive bound.

• vector implementation: How it's done.
• vector typedefs: Type definitions
• vector creation: Creating and destroying vectors.
• vector indexes: Converting indexes to pointers.
• vector adding: Adding elements to a vector.
• vector removing: Removing elements from a vector.
• vector ops: Various operations on a vector.
• vector find: Finding elements.
• vector iteration: Iteration over a vector.
• vector memory: Allocating and freeing memory.
• vector as pqueue: Using a vector as a priority queue.
• vector high: High level functions.

5.9.1 How it's done

This container is heavyweight: its complexity is overkill for simple arrays with fixed size.

The vector structure can be allocated anywhere; the data area is always dynamically allocated and it is described by four pointers of type uint8_t *:

     first_allocated_slot    first_used_slot
     last_allocated_slot     last_used_slot

A slot is a section of the allocated memory that can hold an element; the dimension of the slots is configured at vector initialisation time. A free slot is a slot that does not contain an element; free slots can be present at the beginning and end of the allocated memory. A used slot is a slot that holds an element; used slots are always contiguous in the allocated memory.

Pointer usage charts

Pointers when some slot is used:

      free     used slots           free
     |'''''|.................|''''''''''''''''''''|
     |--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|
     ^     ^              ^                    ^
     |     |              |                    last_allocated_slot
     |     |              |
     |     |              last_used_slot
     |     |
     |     first_used_slot
     |
     first_allocated_slot

pointers when the used area is attached to the beginning of the allocated memory:

           used slots           free
     |.................|''''''''''''''''''''''''''|
     |--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|
     ^              ^                          ^
     |              |                          last_allocated_slot
     |              |
     |              last_used_slot
     |
     first_allocated_slot == first_used_slot

pointers when the used area is attached to the end of the allocated memory:

        free slots           used slots
     |''''''''''''''|.............................|
     |--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|
     ^              ^                          ^
     |              |         last_allocated_slot == last_used_slot
     |              |
     |              first_used_slot
     |
     first_allocated_slot

pointers when the allocated memory is full (all the slots are used):

                      used slots
     |............................................|
     |--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|
     ^                                         ^
     |                        last_allocated_slot == last_used_slot
     |
     |
     |
     first_allocated_slot == first_used_slot

pointers when only one slot is used:

           used
      free slot              free
     |'''''|..|'''''''''''''''''''''''''''''''''''|
     |--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|
     ^     ^                                   ^
     |     |                                   last_allocated_slot
     |     |
     |     first_used_slot == last_used_slot
     |
     first_allocated_slot

pointers when the vector is empty and a non-zero pad area was configured:

       free pad           free slots
       area
     |'''''''''''|''''''''''''''''''''''''''''''''|
     |--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|
     ^        ^  ^                             ^
     |        |  |                             last_allocated_slot
     |        |  first_used_slot
     |        |
     |        last_used_slot
     |
     first_allocated_slot

pointers when the vector is empty and a zero pad area was configured:

                         free slots
        |''''''''''''''''''''''''''''''''''''''''''''|
     |__|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|
     ^  ^                                         ^
     |  |                                         last_allocated_slot
     |  |
     |  first_allocated_slot == first_used_slot
     |
     last_used_slot

Pointers usage rules

• first_allocated_slot references the first byte/slot of the allocated memory; its value is modified only when the memory is reallocated.

  It represents the mimimum allowed value of first_used_slot; when the two are equal: it means that the used area is attached to the beginning of the allocated block.

• last_allocated_slot references the last slot of the allocated memory (not the last byte, unless the size of the slot is one); its value is modified only when the memory is reallocated and is always:

            last_allocated_slot == first_allocated_slot
              + slot_dimension * allocated_slot_number
  

  It represents the maximum allowed value for last_used_slot; when the two are equal: it means that the used area is attached to the end of the allocated block.

• When some slot is used: first_used_slot references the first slot that holds data and it can be casted to the type of contained elements, to reference the first element in the array.

  When the vector is empty: first_used_slot references the first byte after a (dynamic and configurable) padding area; if the size of the padding area is zero: its value is equal to first_allocated_slot.

  first_used_slot can be accessed to start a forward iteration over all the elements in the array.

• When the array is used: last_used_slot references the first byte of the last used slot.

  When the array is empty: last_used_slot has the value of first_used_slot minus the slot dimension.

  last_used_slot can be accessed to start a backward iteration over all the elements in the array.

• When some slot is used, it is always:

            first_used_slot <= last_used_slot
  

  the two are equal when only one slot is used; it must always be:

            number_of_used_slots * slot_dimension ==
                 last_used_slot - first_used_slot + slot_dimension
  

• When no slots are used, it is always:

            first_used_slot == last_used_slot + slot_dimension
  

  and first_used_slot is set to reference the beginning of the padding area. We use this definition of empty vector so that it is possible to iterate with:

            uint8_t *   p;
            
            for (p =  vector->first_used_slot;
                 p <= vector->last_used_slot;
                 p += vector->slot_dimension) { ... }
            
            for (p =  vector->last_used_slot;
                 p >= vector->first_used_slot;
                 p -= vector->slot_dimension) { ... }
  

The padding area, whose starting size can be configured, has the purpose of allowing fast insertion of elements at the beginning, with no reallocation of the memory block.

5.9.2 Type definitions

5.9.3 Creating and destroying vectors

The construction of a new vector is a 3–step sequence: declaration, configuration, allocation:

     ucl_vector_config_t     C;
     ucl_vector_t            V;
     size_t  slot_dimension  = ...;
     size_t  number_of_slots = ...;
     
     ucl_vector_initialise_config(C, slot_dimension, number_of_slots);
     ucl_vector_alloc(V, C);

if we want to set custom values:

     ucl_vector_config_t     C;
     ucl_vector_t            V;
     size_t  slot_dimension  =   16;
     size_t  number_of_slots = 1024;
     
     ucl_vector_initialise_config(C, slot_dimension, number_of_slots);
     C->step_up              = 128;
     C->step_down            = 264;
     C->size_of_padding_area =  32;
     ucl_vector_alloc(V, C);

Configuration functions

After the invocation to the configuration functions, the user's code may override the default values by explicitly setting them before invoking the allocator function. All the functions select ucl_memory_alloc() as allocation function and set to zero the comparison structure.

Default values

The following are the default values ucl_vector_initialise_config() puts into the ucl_vector_config_t structure: a set of preprocessor symbols declared in ucl.h. The declarations allow overriding, they are in the form:

     #ifndef UCL_VECTOR_DEFAULT_STEP_UP
     #  define UCL_VECTOR_DEFAULT_STEP_UP     8
     #endif

Construction and destruction functions

Inspection functions

Updating configuration functions

The following functions can be applied to an already constructed vector.

Special functions

5.9.4 Converting indexes to pointers

• vector indexes i2p: Index to pointer conversion.
• vector indexes p2i: Pointer to index conversion.
• vector indexes validation: Validating indexes.
• vector indexes range: Range functions.
• vector indexes block: Range/block conversion.

5.9.4.1 Index to pointer conversion

5.9.4.2 Pointer to index conversion

5.9.4.3 Validating indexes

5.9.4.4 Range functions

Notice that to build the range of indexes from the beginning of a vector to a selected position we just need to do:

     ucl_range_t     range;
     
     ucl_range_set_min_max(range, 0, position);

5.9.4.5 Range/block conversion

5.9.5 Adding elements to a vector

The correct sequence of function calls required to insert a new element is: enlarge the vector, acquire the pointer, make a free slot, copy the value. Example of insertion:

     ucl_vector_t     vector;
     ucl_index_t      index;
     data_type_t      data;
     data_type_t *    ptr;
     
     ...
     
     data  = ...;
     index = ...;
     ucl_vector_enlarge(vector);
     ptr   = ucl_vector_index_to_new_slot(vector, index);
     ptr   = ucl_vector_insert(vector, ptr);
     *ptr  = data;

example of insert sort operation:

     ucl_vector_t     vector;
     ucl_index_t      index;
     data_type_t      data;
     data_type_t *    ptr;
     
     ...
     
     data  = ...;
     index = ...;
     ucl_vector_enlarge(vector);
     ptr   = ucl_vector_insert_sort(vector, &data);
     *ptr  = data;

5.9.6 Removing elements from a vector

After the invocation of this function, it's possible to attempt a reallocation of the array to free some unused memory with a call to ucl_vector_restrict().

Example of data erasure:

     ucl_vector_t     V;
     ucl_index_t      index;
     data_type_t *    ptr;
     
     ...
     
     index = ...
     ptr   = ucl_vector_index_to_slot(V, index);
     ucl_vector_erase(V, ptr);
     ucl_vector_restrict(V);

example of data extraction:

     ucl_vector_t     V;
     ucl_index_t      index;
     data_type_t *    ptr;
     data_type_t      data;
     
     ...
     
     index = ...
     ptr   = ucl_vector_index_to_slot(V, index);
     data  = *ptr;
     ucl_vector_erase(V, ptr);
     ucl_vector_restrict(V);

5.9.7 Various operations on a vector

Dimension inspection

Access to memory blocks

Sorting

5.9.8 Finding elements

The functions described in this section search for an element in the vector, given a copy of the element to be found. The D argument represents the element to be found, it's used as first argument to the comparison function.

The return value is always a pointer to the found element in the array, or NULL if the element is not present.

5.9.9 Iteration over a vector

It's easy to iterate over all the elements of a vector. Example of forward iteration:

     ucl_vector_t    V;
     data_type_t *   P;
     data_type_t *   end = ucl_vector_back(V);
     
     for (P = ucl_vector_front(V); P <= end; ++P)
       {
         ... *P ...
       }

example of backward iteration:

     ucl_vector_t    V;
     data_type_t *   P;
     data_type_t *   end = ucl_vector_front(V);
     
     for (P = ucl_vector_back(V); P >= end; --P)
       {
         ... *P ...
       }

nevertheless the following iterators are provided; iterators for details on iteration.

5.9.10 Allocating and freeing memory

• vector memory intro: Introduction to vector memory handling.
• vector memory enlarge: Enlarging allocated memory.
• vector memory restrict: Restricting allocated memory.
• vector memory misc: Miscellaneous memory functions.

5.9.10.1 Introduction to vector memory handling

The allocation policy for a vector container is ruled by the arguments stored into the configuration structure (vector creation). The rules are:

• an initial number of slots is selected and an array of such size is allocated;
• an optional number of slots to be kept free at the beginning of the array is selected, so elements can be moved there when inserting new slots;
• the function ucl_vector_enlarge() enlarges the array when one of the two conditions are true:
  • the array is full;
  • a specific number of free slots is requested and there are not enough in the array;
• a “step up” number is selected: when the array is reallocated to be enlarged, the new size is the minimum multiple of this number greater than the number of elements in the container (in units of slot size):

            rest = old_size % step_up
            new_size = old_size + (rest)? rest : step_up
  

• a “step down” number is selected: when ucl_vector_restrict() has to determine if the array has to be reallocated for restriction, the operation is performed if there are at least that number of free slots; the new size is computed with the following formula (in units of slot size):

            rest = old_size % step_up
            new_size = old_size - step_down
            new_size += (rest)? rest : step_up
  

  example:

            old_size  = 20
            step_up   = 4
            step_down = 10
            
            rest     = 20 %  4 =  0
            new_size = 20 - 10 = 10
            new_size = 10 +  4 = 14
  

  notice that if step_up >= step_down it can result that new_size >= old_size, example:

            old_size  = 10
            step_up   = 4
            step_down = 2
            
            rest     = 10 % 4 = 2
            new_size = 10 - 2 = 8
            new_size =  8 + 2 = 10
  

  another example:

            old_size  = 11
            step_up   = 4
            step_down = 2
            
            rest     = 11 % 4 = 3
            new_size = 11 - 2 = 9
            new_size =  9 + 3 = 12
  

  that is why ucl_vector_alloc() sets step_down to a value greater than step_up.

By default the UCL allocator is used (memory functions), but it is possible to register a vector–specific allocator.

5.9.10.2 Enlarging allocated memory

5.9.10.3 Restricting allocated memory

5.9.10.4 Miscellaneous memory functions

5.9.11 Using a vector as a priority queue

The vector structure provides all the functions required to implement a priority queue. This is a structure in which elements are associated with keys: when an element is added and the structure is kept sorted comparing its key with the keys of the elements already in the container.

Let's say we have declared a structure like this:

     typedef struct pair_t {
       key_t   key;
       val_t   val;
     } pair_t;

and a ucl_comparison_t function+context to compare keys.

If any time a pair_t must be inserted in the vector we use the ucl_vector_insert_sort() function to determine the insertion position, the elements will be kept sorted according to the key values and comparison algorithm.

Then ucl_vector_front() or ucl_vector_back() can be used to extract the element with lesser or greater key.

5.9.12 High level functions

The functions described in this section are built upon the basic ones; some of them invoke the enlarge/restrict memory functions.

• vector high stack: Stack and queue.
• vector high append: Appending data to a vector.
• vector high insert: Inserting into a vector.
• vector high erase: Removing from a vector.
• vector high access: Setters and getters.
• vector high compare: Comparing vectors.
• vector high apply: Applying functions.

5.9.12.1 Stack and queue

Notice that the “top” operations of the stack and queue are already implemented by ucl_vector_front() and ucl_vector_back().

5.9.12.2 Appending data to a vector

In the following functions the dst vector must be an already allocated vector.

5.9.12.3 Inserting into a vector

5.9.12.4 Removing from a vector

5.9.12.5 Setters and getters

5.9.12.6 Comparing vectors

5.9.12.7 Applying functions

The functions described in this section allow us to apply a function, in the form of a callback (typedefs callback), to each element in a vector or to each element in a range over a vector. The “for each” kind leaves to the callback the responsibility to produce a result, while the “map” kind produces a vector holding processed elements.

6 Container iteration

Each container has its iteration constructors that must be invoked explicitly, but the functions used to do the actual iterations and to access the objects are accessed through a set of macros.

6.1 Examples

Example of iterator usage:

     ucl_value_t       val;
     ucl_iterator_t    iterator;
     ucl_map_link_t *  link_p;
     
     ...
     
     for (ucl_map_iterator_inorder(this, iterator);
          ucl_iterator_more(iterator);
          ucl_iterator_next(iterator))
       {
         link_p = ucl_iterator_ptr(iterator);
         val = ucl_map_getval(link_p);
       }

7 Miscellaneous functions

• misc version: Version functions.
• misc compar: Comparison functions.
• misc sort: Sorting functions.

7.1 Version functions

7.2 Comparison functions

All the following function have prototype matching ucl_comparison_fun_t; for all of them data is unused and the return value is: 0 if a equals b; 1 if a is greater than b; -1 if a is lesser than b.

7.3 Sorting functions

Appendix A Bibliography and references

Ellis Horowitz, Sartaj Sahni and Susan Anderson–Freed. Strutture dati in C. McGraw–Hill, 1993.

Bjarne Stroustroup. C++. Addison-Wesley, 1997.

Appendix B GNU General Public License

     Copyright © 2007 Free Software Foundation, Inc. http://fsf.org/
     
     Everyone is permitted to copy and distribute verbatim copies of this
     license document, but changing it is not allowed.

Preamble

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   “Copyright” also means copyright-like laws that apply to other kinds of works, such as semiconductor masks.

   “The Program” refers to any copyrightable work licensed under this License. Each licensee is addressed as “you”. “Licensees” and “recipients” may be individuals or organizations.

   To “modify” a work means to copy from or adapt all or part of the work in a fashion requiring copyright permission, other than the making of an exact copy. The resulting work is called a “modified version” of the earlier work or a work “based on” the earlier work.

   A “covered work” means either the unmodified Program or a work based on the Program.

   To “propagate” a work means to do anything with it that, without permission, would make you directly or secondarily liable for infringement under applicable copyright law, except executing it on a computer or modifying a private copy. Propagation includes copying, distribution (with or without modification), making available to the public, and in some countries other activities as well.

   To “convey” a work means any kind of propagation that enables other parties to make or receive copies. Mere interaction with a user through a computer network, with no transfer of a copy, is not conveying.

   An interactive user interface displays “Appropriate Legal Notices” to the extent that it includes a convenient and prominently visible feature that (1) displays an appropriate copyright notice, and (2) tells the user that there is no warranty for the work (except to the extent that warranties are provided), that licensees may convey the work under this License, and how to view a copy of this License. If the interface presents a list of user commands or options, such as a menu, a prominent item in the list meets this criterion.

1. Source Code.

   The “source code” for a work means the preferred form of the work for making modifications to it. “Object code” means any non-source form of a work.

   A “Standard Interface” means an interface that either is an official standard defined by a recognized standards body, or, in the case of interfaces specified for a particular programming language, one that is widely used among developers working in that language.

   The “System Libraries” of an executable work include anything, other than the work as a whole, that (a) is included in the normal form of packaging a Major Component, but which is not part of that Major Component, and (b) serves only to enable use of the work with that Major Component, or to implement a Standard Interface for which an implementation is available to the public in source code form. A “Major Component”, in this context, means a major essential component (kernel, window system, and so on) of the specific operating system (if any) on which the executable work runs, or a compiler used to produce the work, or an object code interpreter used to run it.

   The “Corresponding Source” for a work in object code form means all the source code needed to generate, install, and (for an executable work) run the object code and to modify the work, including scripts to control those activities. However, it does not include the work's System Libraries, or general-purpose tools or generally available free programs which are used unmodified in performing those activities but which are not part of the work. For example, Corresponding Source includes interface definition files associated with source files for the work, and the source code for shared libraries and dynamically linked subprograms that the work is specifically designed to require, such as by intimate data communication or control flow between those subprograms and other parts of the work.

   The Corresponding Source need not include anything that users can regenerate automatically from other parts of the Corresponding Source.

   The Corresponding Source for a work in source code form is that same work.

2. Basic Permissions.

   All rights granted under this License are granted for the term of copyright on the Program, and are irrevocable provided the stated conditions are met. This License explicitly affirms your unlimited permission to run the unmodified Program. The output from running a covered work is covered by this License only if the output, given its content, constitutes a covered work. This License acknowledges your rights of fair use or other equivalent, as provided by copyright law.

   You may make, run and propagate covered works that you do not convey, without conditions so long as your license otherwise remains in force. You may convey covered works to others for the sole purpose of having them make modifications exclusively for you, or provide you with facilities for running those works, provided that you comply with the terms of this License in conveying all material for which you do not control copyright. Those thus making or running the covered works for you must do so exclusively on your behalf, under your direction and control, on terms that prohibit them from making any copies of your copyrighted material outside their relationship with you.

   Conveying under any other circumstances is permitted solely under the conditions stated below. Sublicensing is not allowed; section 10 makes it unnecessary.

3. Protecting Users' Legal Rights From Anti-Circumvention Law.

   No covered work shall be deemed part of an effective technological measure under any applicable law fulfilling obligations under article 11 of the WIPO copyright treaty adopted on 20 December 1996, or similar laws prohibiting or restricting circumvention of such measures.

   When you convey a covered work, you waive any legal power to forbid circumvention of technological measures to the extent such circumvention is effected by exercising rights under this License with respect to the covered work, and you disclaim any intention to limit operation or modification of the work as a means of enforcing, against the work's users, your or third parties' legal rights to forbid circumvention of technological measures.

4. Conveying Verbatim Copies.

   You may convey verbatim copies of the Program's source code as you receive it, in any medium, provided that you conspicuously and appropriately publish on each copy an appropriate copyright notice; keep intact all notices stating that this License and any non-permissive terms added in accord with section 7 apply to the code; keep intact all notices of the absence of any warranty; and give all recipients a copy of this License along with the Program.

   You may charge any price or no price for each copy that you convey, and you may offer support or warranty protection for a fee.

5. Conveying Modified Source Versions.

   You may convey a work based on the Program, or the modifications to produce it from the Program, in the form of source code under the terms of section 4, provided that you also meet all of these conditions:

   1. The work must carry prominent notices stating that you modified it, and giving a relevant date.
   2. The work must carry prominent notices stating that it is released under this License and any conditions added under section 7. This requirement modifies the requirement in section 4 to “keep intact all notices”.
   3. You must license the entire work, as a whole, under this License to anyone who comes into possession of a copy. This License will therefore apply, along with any applicable section 7 additional terms, to the whole of the work, and all its parts, regardless of how they are packaged. This License gives no permission to license the work in any other way, but it does not invalidate such permission if you have separately received it.
   4. If the work has interactive user interfaces, each must display Appropriate Legal Notices; however, if the Program has interactive interfaces that do not display Appropriate Legal Notices, your work need not make them do so.

   A compilation of a covered work with other separate and independent works, which are not by their nature extensions of the covered work, and which are not combined with it such as to form a larger program, in or on a volume of a storage or distribution medium, is called an “aggregate” if the compilation and its resulting copyright are not used to limit the access or legal rights of the compilation's users beyond what the individual works permit. Inclusion of a covered work in an aggregate does not cause this License to apply to the other parts of the aggregate.

6. Conveying Non-Source Forms.

   You may convey a covered work in object code form under the terms of sections 4 and 5, provided that you also convey the machine-readable Corresponding Source under the terms of this License, in one of these ways:

   1. Convey the object code in, or embodied in, a physical product (including a physical distribution medium), accompanied by the Corresponding Source fixed on a durable physical medium customarily used for software interchange.
   2. Convey the object code in, or embodied in, a physical product (including a physical distribution medium), accompanied by a written offer, valid for at least three years and valid for as long as you offer spare parts or customer support for that product model, to give anyone who possesses the object code either (1) a copy of the Corresponding Source for all the software in the product that is covered by this License, on a durable physical medium customarily used for software interchange, for a price no more than your reasonable cost of physically performing this conveying of source, or (2) access to copy the Corresponding Source from a network server at no charge.
   3. Convey individual copies of the object code with a copy of the written offer to provide the Corresponding Source. This alternative is allowed only occasionally and noncommercially, and only if you received the object code with such an offer, in accord with subsection 6b.
   4. Convey the object code by offering access from a designated place (gratis or for a charge), and offer equivalent access to the Corresponding Source in the same way through the same place at no further charge. You need not require recipients to copy the Corresponding Source along with the object code. If the place to copy the object code is a network server, the Corresponding Source may be on a different server (operated by you or a third party) that supports equivalent copying facilities, provided you maintain clear directions next to the object code saying where to find the Corresponding Source. Regardless of what server hosts the Corresponding Source, you remain obligated to ensure that it is available for as long as needed to satisfy these requirements.
   5. Convey the object code using peer-to-peer transmission, provided you inform other peers where the object code and Corresponding Source of the work are being offered to the general public at no charge under subsection 6d.

   A separable portion of the object code, whose source code is excluded from the Corresponding Source as a System Library, need not be included in conveying the object code work.

   A “User Product” is either (1) a “consumer product”, which means any tangible personal property which is normally used for personal, family, or household purposes, or (2) anything designed or sold for incorporation into a dwelling. In determining whether a product is a consumer product, doubtful cases shall be resolved in favor of coverage. For a particular product received by a particular user, “normally used” refers to a typical or common use of that class of product, regardless of the status of the particular user or of the way in which the particular user actually uses, or expects or is expected to use, the product. A product is a consumer product regardless of whether the product has substantial commercial, industrial or non-consumer uses, unless such uses represent the only significant mode of use of the product.

   “Installation Information” for a User Product means any methods, procedures, authorization keys, or other information required to install and execute modified versions of a covered work in that User Product from a modified version of its Corresponding Source. The information must suffice to ensure that the continued functioning of the modified object code is in no case prevented or interfered with solely because modification has been made.

   If you convey an object code work under this section in, or with, or specifically for use in, a User Product, and the conveying occurs as part of a transaction in which the right of possession and use of the User Product is transferred to the recipient in perpetuity or for a fixed term (regardless of how the transaction is characterized), the Corresponding Source conveyed under this section must be accompanied by the Installation Information. But this requirement does not apply if neither you nor any third party retains the ability to install modified object code on the User Product (for example, the work has been installed in ROM).

   The requirement to provide Installation Information does not include a requirement to continue to provide support service, warranty, or updates for a work that has been modified or installed by the recipient, or for the User Product in which it has been modified or installed. Access to a network may be denied when the modification itself materially and adversely affects the operation of the network or violates the rules and protocols for communication across the network.

   Corresponding Source conveyed, and Installation Information provided, in accord with this section must be in a format that is publicly documented (and with an implementation available to the public in source code form), and must require no special password or key for unpacking, reading or copying.

7. Additional Terms.

   “Additional permissions” are terms that supplement the terms of this License by making exceptions from one or more of its conditions. Additional permissions that are applicable to the entire Program shall be treated as though they were included in this License, to the extent that they are valid under applicable law. If additional permissions apply only to part of the Program, that part may be used separately under those permissions, but the entire Program remains governed by this License without regard to the additional permissions.

   When you convey a copy of a covered work, you may at your option remove any additional permissions from that copy, or from any part of it. (Additional permissions may be written to require their own removal in certain cases when you modify the work.) You may place additional permissions on material, added by you to a covered work, for which you have or can give appropriate copyright permission.

   Notwithstanding any other provision of this License, for material you add to a covered work, you may (if authorized by the copyright holders of that material) supplement the terms of this License with terms:

   1. Disclaiming warranty or limiting liability differently from the terms of sections 15 and 16 of this License; or
   2. Requiring preservation of specified reasonable legal notices or author attributions in that material or in the Appropriate Legal Notices displayed by works containing it; or
   3. Prohibiting misrepresentation of the origin of that material, or requiring that modified versions of such material be marked in reasonable ways as different from the original version; or
   4. Limiting the use for publicity purposes of names of licensors or authors of the material; or
   5. Declining to grant rights under trademark law for use of some trade names, trademarks, or service marks; or
   6. Requiring indemnification of licensors and authors of that material by anyone who conveys the material (or modified versions of it) with contractual assumptions of liability to the recipient, for any liability that these contractual assumptions directly impose on those licensors and authors.

   All other non-permissive additional terms are considered “further restrictions” within the meaning of section 10. If the Program as you received it, or any part of it, contains a notice stating that it is governed by this License along with a term that is a further restriction, you may remove that term. If a license document contains a further restriction but permits relicensing or conveying under this License, you may add to a covered work material governed by the terms of that license document, provided that the further restriction does not survive such relicensing or conveying.

   If you add terms to a covered work in accord with this section, you must place, in the relevant source files, a statement of the additional terms that apply to those files, or a notice indicating where to find the applicable terms.

   Additional terms, permissive or non-permissive, may be stated in the form of a separately written license, or stated as exceptions; the above requirements apply either way.

8. Termination.

   You may not propagate or modify a covered work except as expressly provided under this License. Any attempt otherwise to propagate or modify it is void, and will automatically terminate your rights under this License (including any patent licenses granted under the third paragraph of section 11).

   However, if you cease all violation of this License, then your license from a particular copyright holder is reinstated (a) provisionally, unless and until the copyright holder explicitly and finally terminates your license, and (b) permanently, if the copyright holder fails to notify you of the violation by some reasonable means prior to 60 days after the cessation.

   Moreover, your license from a particular copyright holder is reinstated permanently if the copyright holder notifies you of the violation by some reasonable means, this is the first time you have received notice of violation of this License (for any work) from that copyright holder, and you cure the violation prior to 30 days after your receipt of the notice.

   Termination of your rights under this section does not terminate the licenses of parties who have received copies or rights from you under this License. If your rights have been terminated and not permanently reinstated, you do not qualify to receive new licenses for the same material under section 10.

9. Acceptance Not Required for Having Copies.

   You are not required to accept this License in order to receive or run a copy of the Program. Ancillary propagation of a covered work occurring solely as a consequence of using peer-to-peer transmission to receive a copy likewise does not require acceptance. However, nothing other than this License grants you permission to propagate or modify any covered work. These actions infringe copyright if you do not accept this License. Therefore, by modifying or propagating a covered work, you indicate your acceptance of this License to do so.

10. Automatic Licensing of Downstream Recipients.

    Each time you convey a covered work, the recipient automatically receives a license from the original licensors, to run, modify and propagate that work, subject to this License. You are not responsible for enforcing compliance by third parties with this License.

    An “entity transaction” is a transaction transferring control of an organization, or substantially all assets of one, or subdividing an organization, or merging organizations. If propagation of a covered work results from an entity transaction, each party to that transaction who receives a copy of the work also receives whatever licenses to the work the party's predecessor in interest had or could give under the previous paragraph, plus a right to possession of the Corresponding Source of the work from the predecessor in interest, if the predecessor has it or can get it with reasonable efforts.

    You may not impose any further restrictions on the exercise of the rights granted or affirmed under this License. For example, you may not impose a license fee, royalty, or other charge for exercise of rights granted under this License, and you may not initiate litigation (including a cross-claim or counterclaim in a lawsuit) alleging that any patent claim is infringed by making, using, selling, offering for sale, or importing the Program or any portion of it.

11. Patents.

    A “contributor” is a copyright holder who authorizes use under this License of the Program or a work on which the Program is based. The work thus licensed is called the contributor's “contributor version”.

    A contributor's “essential patent claims” are all patent claims owned or controlled by the contributor, whether already acquired or hereafter acquired, that would be infringed by some manner, permitted by this License, of making, using, or selling its contributor version, but do not include claims that would be infringed only as a consequence of further modification of the contributor version. For purposes of this definition, “control” includes the right to grant patent sublicenses in a manner consistent with the requirements of this License.

    Each contributor grants you a non-exclusive, worldwide, royalty-free patent license under the contributor's essential patent claims, to make, use, sell, offer for sale, import and otherwise run, modify and propagate the contents of its contributor version.

    In the following three paragraphs, a “patent license” is any express agreement or commitment, however denominated, not to enforce a patent (such as an express permission to practice a patent or covenant not to sue for patent infringement). To “grant” such a patent license to a party means to make such an agreement or commitment not to enforce a patent against the party.

    If you convey a covered work, knowingly relying on a patent license, and the Corresponding Source of the work is not available for anyone to copy, free of charge and under the terms of this License, through a publicly available network server or other readily accessible means, then you must either (1) cause the Corresponding Source to be so available, or (2) arrange to deprive yourself of the benefit of the patent license for this particular work, or (3) arrange, in a manner consistent with the requirements of this License, to extend the patent license to downstream recipients. “Knowingly relying” means you have actual knowledge that, but for the patent license, your conveying the covered work in a country, or your recipient's use of the covered work in a country, would infringe one or more identifiable patents in that country that you have reason to believe are valid.

    If, pursuant to or in connection with a single transaction or arrangement, you convey, or propagate by procuring conveyance of, a covered work, and grant a patent license to some of the parties receiving the covered work authorizing them to use, propagate, modify or convey a specific copy of the covered work, then the patent license you grant is automatically extended to all recipients of the covered work and works based on it.

    A patent license is “discriminatory” if it does not include within the scope of its coverage, prohibits the exercise of, or is conditioned on the non-exercise of one or more of the rights that are specifically granted under this License. You may not convey a covered work if you are a party to an arrangement with a third party that is in the business of distributing software, under which you make payment to the third party based on the extent of your activity of conveying the work, and under which the third party grants, to any of the parties who would receive the covered work from you, a discriminatory patent license (a) in connection with copies of the covered work conveyed by you (or copies made from those copies), or (b) primarily for and in connection with specific products or compilations that contain the covered work, unless you entered into that arrangement, or that patent license was granted, prior to 28 March 2007.

    Nothing in this License shall be construed as excluding or limiting any implied license or other defenses to infringement that may otherwise be available to you under applicable patent law.

12. No Surrender of Others' Freedom.

    If conditions are imposed on you (whether by court order, agreement or otherwise) that contradict the conditions of this License, they do not excuse you from the conditions of this License. If you cannot convey a covered work so as to satisfy simultaneously your obligations under this License and any other pertinent obligations, then as a consequence you may not convey it at all. For example, if you agree to terms that obligate you to collect a royalty for further conveying from those to whom you convey the Program, the only way you could satisfy both those terms and this License would be to refrain entirely from conveying the Program.

13. Use with the GNU Affero General Public License.

    Notwithstanding any other provision of this License, you have permission to link or combine any covered work with a work licensed under version 3 of the GNU Affero General Public License into a single combined work, and to convey the resulting work. The terms of this License will continue to apply to the part which is the covered work, but the special requirements of the GNU Affero General Public License, section 13, concerning interaction through a network will apply to the combination as such.

14. Revised Versions of this License.

    The Free Software Foundation may publish revised and/or new versions of the GNU General Public License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns.

    Each version is given a distinguishing version number. If the Program specifies that a certain numbered version of the GNU General Public License “or any later version” applies to it, you have the option of following the terms and conditions either of that numbered version or of any later version published by the Free Software Foundation. If the Program does not specify a version number of the GNU General Public License, you may choose any version ever published by the Free Software Foundation.

    If the Program specifies that a proxy can decide which future versions of the GNU General Public License can be used, that proxy's public statement of acceptance of a version permanently authorizes you to choose that version for the Program.

    Later license versions may give you additional or different permissions. However, no additional obligations are imposed on any author or copyright holder as a result of your choosing to follow a later version.

15. Disclaimer of Warranty.

    THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM “AS IS” WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.

16. Limitation of Liability.

    IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.

17. Interpretation of Sections 15 and 16.

    If the disclaimer of warranty and limitation of liability provided above cannot be given local legal effect according to their terms, reviewing courts shall apply local law that most closely approximates an absolute waiver of all civil liability in connection with the Program, unless a warranty or assumption of liability accompanies a copy of the Program in return for a fee.

END OF TERMS AND CONDITIONS

How to Apply These Terms to Your New Programs

If you develop a new program, and you want it to be of the greatest possible use to the public, the best way to achieve this is to make it free software which everyone can redistribute and change under these terms.

To do so, attach the following notices to the program. It is safest to attach them to the start of each source file to most effectively state the exclusion of warranty; and each file should have at least the “copyright” line and a pointer to where the full notice is found.

     one line to give the program's name and a brief idea of what it does.
     Copyright (C) year name of author
     
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
     the Free Software Foundation, either version 3 of the License, or (at
     your option) any later version.
     
     This program is distributed in the hope that it will be useful, but
     WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     General Public License for more details.
     
     You should have received a copy of the GNU General Public License
     along with this program.  If not, see http://www.gnu.org/licenses/.

Also add information on how to contact you by electronic and paper mail.

If the program does terminal interaction, make it output a short notice like this when it starts in an interactive mode:

     program Copyright (C) year name of author
     This program comes with ABSOLUTELY NO WARRANTY; for details type ‘show w’.
     This is free software, and you are welcome to redistribute it
     under certain conditions; type ‘show c’ for details.

The hypothetical commands ‘show w’ and ‘show c’ should show the appropriate parts of the General Public License. Of course, your program's commands might be different; for a GUI interface, you would use an “about box”.

You should also get your employer (if you work as a programmer) or school, if any, to sign a “copyright disclaimer” for the program, if necessary. For more information on this, and how to apply and follow the GNU GPL, see http://www.gnu.org/licenses/.

The GNU General Public License does not permit incorporating your program into proprietary programs. If your program is a subroutine library, you may consider it more useful to permit linking proprietary applications with the library. If this is what you want to do, use the GNU Lesser General Public License instead of this License. But first, please read http://www.gnu.org/philosophy/why-not-lgpl.html.

Appendix C GNU Free Documentation License

     Copyright © 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc.
     http://fsf.org/
     
     Everyone is permitted to copy and distribute verbatim copies
     of this license document, but changing it is not allowed.

0. PREAMBLE

   The purpose of this License is to make a manual, textbook, or other functional and useful document free in the sense of freedom: to assure everyone the effective freedom to copy and redistribute it, with or without modifying it, either commercially or noncommercially. Secondarily, this License preserves for the author and publisher a way to get credit for their work, while not being considered responsible for modifications made by others.

   This License is a kind of “copyleft”, which means that derivative works of the document must themselves be free in the same sense. It complements the GNU General Public License, which is a copyleft license designed for free software.

   We have designed this License in order to use it for manuals for free software, because free software needs free documentation: a free program should come with manuals providing the same freedoms that the software does. But this License is not limited to software manuals; it can be used for any textual work, regardless of subject matter or whether it is published as a printed book. We recommend this License principally for works whose purpose is instruction or reference.

1. APPLICABILITY AND DEFINITIONS

   This License applies to any manual or other work, in any medium, that contains a notice placed by the copyright holder saying it can be distributed under the terms of this License. Such a notice grants a world-wide, royalty-free license, unlimited in duration, to use that work under the conditions stated herein. The “Document”, below, refers to any such manual or work. Any member of the public is a licensee, and is addressed as “you”. You accept the license if you copy, modify or distribute the work in a way requiring permission under copyright law.

   A “Modified Version” of the Document means any work containing the Document or a portion of it, either copied verbatim, or with modifications and/or translated into another language.

   A “Secondary Section” is a named appendix or a front-matter section of the Document that deals exclusively with the relationship of the publishers or authors of the Document to the Document's overall subject (or to related matters) and contains nothing that could fall directly within that overall subject. (Thus, if the Document is in part a textbook of mathematics, a Secondary Section may not explain any mathematics.) The relationship could be a matter of historical connection with the subject or with related matters, or of legal, commercial, philosophical, ethical or political position regarding them.

   The “Invariant Sections” are certain Secondary Sections whose titles are designated, as being those of Invariant Sections, in the notice that says that the Document is released under this License. If a section does not fit the above definition of Secondary then it is not allowed to be designated as Invariant. The Document may contain zero Invariant Sections. If the Document does not identify any Invariant Sections then there are none.

   The “Cover Texts” are certain short passages of text that are listed, as Front-Cover Texts or Back-Cover Texts, in the notice that says that the Document is released under this License. A Front-Cover Text may be at most 5 words, and a Back-Cover Text may be at most 25 words.

   A “Transparent” copy of the Document means a machine-readable copy, represented in a format whose specification is available to the general public, that is suitable for revising the document straightforwardly with generic text editors or (for images composed of pixels) generic paint programs or (for drawings) some widely available drawing editor, and that is suitable for input to text formatters or for automatic translation to a variety of formats suitable for input to text formatters. A copy made in an otherwise Transparent file format whose markup, or absence of markup, has been arranged to thwart or discourage subsequent modification by readers is not Transparent. An image format is not Transparent if used for any substantial amount of text. A copy that is not “Transparent” is called “Opaque”.

   Examples of suitable formats for Transparent copies include plain ascii without markup, Texinfo input format, LaTeX input format, SGML or XML using a publicly available DTD, and standard-conforming simple HTML, PostScript or PDF designed for human modification. Examples of transparent image formats include PNG, XCF and JPG. Opaque formats include proprietary formats that can be read and edited only by proprietary word processors, SGML or XML for which the DTD and/or processing tools are not generally available, and the machine-generated HTML, PostScript or PDF produced by some word processors for output purposes only.

   The “Title Page” means, for a printed book, the title page itself, plus such following pages as are needed to hold, legibly, the material this License requires to appear in the title page. For works in formats which do not have any title page as such, “Title Page” means the text near the most prominent appearance of the work's title, preceding the beginning of the body of the text.

   The “publisher” means any person or entity that distributes copies of the Document to the public.

   A section “Entitled XYZ” means a named subunit of the Document whose title either is precisely XYZ or contains XYZ in parentheses following text that translates XYZ in another language. (Here XYZ stands for a specific section name mentioned below, such as “Acknowledgements”, “Dedications”, “Endorsements”, or “History”.) To “Preserve the Title” of such a section when you modify the Document means that it remains a section “Entitled XYZ” according to this definition.

   The Document may include Warranty Disclaimers next to the notice which states that this License applies to the Document. These Warranty Disclaimers are considered to be included by reference in this License, but only as regards disclaiming warranties: any other implication that these Warranty Disclaimers may have is void and has no effect on the meaning of this License.

2. VERBATIM COPYING

   You may copy and distribute the Document in any medium, either commercially or noncommercially, provided that this License, the copyright notices, and the license notice saying this License applies to the Document are reproduced in all copies, and that you add no other conditions whatsoever to those of this License. You may not use technical measures to obstruct or control the reading or further copying of the copies you make or distribute. However, you may accept compensation in exchange for copies. If you distribute a large enough number of copies you must also follow the conditions in section 3.

   You may also lend copies, under the same conditions stated above, and you may publicly display copies.

3. COPYING IN QUANTITY

   If you publish printed copies (or copies in media that commonly have printed covers) of the Document, numbering more than 100, and the Document's license notice requires Cover Texts, you must enclose the copies in covers that carry, clearly and legibly, all these Cover Texts: Front-Cover Texts on the front cover, and Back-Cover Texts on the back cover. Both covers must also clearly and legibly identify you as the publisher of these copies. The front cover must present the full title with all words of the title equally prominent and visible. You may add other material on the covers in addition. Copying with changes limited to the covers, as long as they preserve the title of the Document and satisfy these conditions, can be treated as verbatim copying in other respects.

   If the required texts for either cover are too voluminous to fit legibly, you should put the first ones listed (as many as fit reasonably) on the actual cover, and continue the rest onto adjacent pages.

   If you publish or distribute Opaque copies of the Document numbering more than 100, you must either include a machine-readable Transparent copy along with each Opaque copy, or state in or with each Opaque copy a computer-network location from which the general network-using public has access to download using public-standard network protocols a complete Transparent copy of the Document, free of added material. If you use the latter option, you must take reasonably prudent steps, when you begin distribution of Opaque copies in quantity, to ensure that this Transparent copy will remain thus accessible at the stated location until at least one year after the last time you distribute an Opaque copy (directly or through your agents or retailers) of that edition to the public.

   It is requested, but not required, that you contact the authors of the Document well before redistributing any large number of copies, to give them a chance to provide you with an updated version of the Document.

4. MODIFICATIONS

   You may copy and distribute a Modified Version of the Document under the conditions of sections 2 and 3 above, provided that you release the Modified Version under precisely this License, with the Modified Version filling the role of the Document, thus licensing distribution and modification of the Modified Version to whoever possesses a copy of it. In addition, you must do these things in the Modified Version:

   1. Use in the Title Page (and on the covers, if any) a title distinct from that of the Document, and from those of previous versions (which should, if there were any, be listed in the History section of the Document). You may use the same title as a previous version if the original publisher of that version gives permission.
   2. List on the Title Page, as authors, one or more persons or entities responsible for authorship of the modifications in the Modified Version, together with at least five of the principal authors of the Document (all of its principal authors, if it has fewer than five), unless they release you from this requirement.
   3. State on the Title page the name of the publisher of the Modified Version, as the publisher.
   4. Preserve all the copyright notices of the Document.
   5. Add an appropriate copyright notice for your modifications adjacent to the other copyright notices.
   6. Include, immediately after the copyright notices, a license notice giving the public permission to use the Modified Version under the terms of this License, in the form shown in the Addendum below.
   7. Preserve in that license notice the full lists of Invariant Sections and required Cover Texts given in the Document's license notice.
   8. Include an unaltered copy of this License.
   9. Preserve the section Entitled “History”, Preserve its Title, and add to it an item stating at least the title, year, new authors, and publisher of the Modified Version as given on the Title Page. If there is no section Entitled “History” in the Document, create one stating the title, year, authors, and publisher of the Document as given on its Title Page, then add an item describing the Modified Version as stated in the previous sentence.
   10. Preserve the network location, if any, given in the Document for public access to a Transparent copy of the Document, and likewise the network locations given in the Document for previous versions it was based on. These may be placed in the “History” section. You may omit a network location for a work that was published at least four years before the Document itself, or if the original publisher of the version it refers to gives permission.
   11. For any section Entitled “Acknowledgements” or “Dedications”, Preserve the Title of the section, and preserve in the section all the substance and tone of each of the contributor acknowledgements and/or dedications given therein.
   12. Preserve all the Invariant Sections of the Document, unaltered in their text and in their titles. Section numbers or the equivalent are not considered part of the section titles.
   13. Delete any section Entitled “Endorsements”. Such a section may not be included in the Modified Version.
   14. Do not retitle any existing section to be Entitled “Endorsements” or to conflict in title with any Invariant Section.
   15. Preserve any Warranty Disclaimers.

   If the Modified Version includes new front-matter sections or appendices that qualify as Secondary Sections and contain no material copied from the Document, you may at your option designate some or all of these sections as invariant. To do this, add their titles to the list of Invariant Sections in the Modified Version's license notice. These titles must be distinct from any other section titles.

   You may add a section Entitled “Endorsements”, provided it contains nothing but endorsements of your Modified Version by various parties—for example, statements of peer review or that the text has been approved by an organization as the authoritative definition of a standard.

   You may add a passage of up to five words as a Front-Cover Text, and a passage of up to 25 words as a Back-Cover Text, to the end of the list of Cover Texts in the Modified Version. Only one passage of Front-Cover Text and one of Back-Cover Text may be added by (or through arrangements made by) any one entity. If the Document already includes a cover text for the same cover, previously added by you or by arrangement made by the same entity you are acting on behalf of, you may not add another; but you may replace the old one, on explicit permission from the previous publisher that added the old one.

   The author(s) and publisher(s) of the Document do not by this License give permission to use their names for publicity for or to assert or imply endorsement of any Modified Version.

5. COMBINING DOCUMENTS

   You may combine the Document with other documents released under this License, under the terms defined in section 4 above for modified versions, provided that you include in the combination all of the Invariant Sections of all of the original documents, unmodified, and list them all as Invariant Sections of your combined work in its license notice, and that you preserve all their Warranty Disclaimers.

   The combined work need only contain one copy of this License, and multiple identical Invariant Sections may be replaced with a single copy. If there are multiple Invariant Sections with the same name but different contents, make the title of each such section unique by adding at the end of it, in parentheses, the name of the original author or publisher of that section if known, or else a unique number. Make the same adjustment to the section titles in the list of Invariant Sections in the license notice of the combined work.

   In the combination, you must combine any sections Entitled “History” in the various original documents, forming one section Entitled “History”; likewise combine any sections Entitled “Acknowledgements”, and any sections Entitled “Dedications”. You must delete all sections Entitled “Endorsements.”

6. COLLECTIONS OF DOCUMENTS

   You may make a collection consisting of the Document and other documents released under this License, and replace the individual copies of this License in the various documents with a single copy that is included in the collection, provided that you follow the rules of this License for verbatim copying of each of the documents in all other respects.

   You may extract a single document from such a collection, and distribute it individually under this License, provided you insert a copy of this License into the extracted document, and follow this License in all other respects regarding verbatim copying of that document.

7. AGGREGATION WITH INDEPENDENT WORKS

   A compilation of the Document or its derivatives with other separate and independent documents or works, in or on a volume of a storage or distribution medium, is called an “aggregate” if the copyright resulting from the compilation is not used to limit the legal rights of the compilation's users beyond what the individual works permit. When the Document is included in an aggregate, this License does not apply to the other works in the aggregate which are not themselves derivative works of the Document.

   If the Cover Text requirement of section 3 is applicable to these copies of the Document, then if the Document is less than one half of the entire aggregate, the Document's Cover Texts may be placed on covers that bracket the Document within the aggregate, or the electronic equivalent of covers if the Document is in electronic form. Otherwise they must appear on printed covers that bracket the whole aggregate.

8. TRANSLATION

   Translation is considered a kind of modification, so you may distribute translations of the Document under the terms of section 4. Replacing Invariant Sections with translations requires special permission from their copyright holders, but you may include translations of some or all Invariant Sections in addition to the original versions of these Invariant Sections. You may include a translation of this License, and all the license notices in the Document, and any Warranty Disclaimers, provided that you also include the original English version of this License and the original versions of those notices and disclaimers. In case of a disagreement between the translation and the original version of this License or a notice or disclaimer, the original version will prevail.

   If a section in the Document is Entitled “Acknowledgements”, “Dedications”, or “History”, the requirement (section 4) to Preserve its Title (section 1) will typically require changing the actual title.

9. TERMINATION

   You may not copy, modify, sublicense, or distribute the Document except as expressly provided under this License. Any attempt otherwise to copy, modify, sublicense, or distribute it is void, and will automatically terminate your rights under this License.

   However, if you cease all violation of this License, then your license from a particular copyright holder is reinstated (a) provisionally, unless and until the copyright holder explicitly and finally terminates your license, and (b) permanently, if the copyright holder fails to notify you of the violation by some reasonable means prior to 60 days after the cessation.

   Moreover, your license from a particular copyright holder is reinstated permanently if the copyright holder notifies you of the violation by some reasonable means, this is the first time you have received notice of violation of this License (for any work) from that copyright holder, and you cure the violation prior to 30 days after your receipt of the notice.

   Termination of your rights under this section does not terminate the licenses of parties who have received copies or rights from you under this License. If your rights have been terminated and not permanently reinstated, receipt of a copy of some or all of the same material does not give you any rights to use it.

10. FUTURE REVISIONS OF THIS LICENSE

    The Free Software Foundation may publish new, revised versions of the GNU Free Documentation License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns. See http://www.gnu.org/copyleft/.

    Each version of the License is given a distinguishing version number. If the Document specifies that a particular numbered version of this License “or any later version” applies to it, you have the option of following the terms and conditions either of that specified version or of any later version that has been published (not as a draft) by the Free Software Foundation. If the Document does not specify a version number of this License, you may choose any version ever published (not as a draft) by the Free Software Foundation. If the Document specifies that a proxy can decide which future versions of this License can be used, that proxy's public statement of acceptance of a version permanently authorizes you to choose that version for the Document.

11. RELICENSING

    “Massive Multiauthor Collaboration Site” (or “MMC Site”) means any World Wide Web server that publishes copyrightable works and also provides prominent facilities for anybody to edit those works. A public wiki that anybody can edit is an example of such a server. A “Massive Multiauthor Collaboration” (or “MMC”) contained in the site means any set of copyrightable works thus published on the MMC site.

    “CC-BY-SA” means the Creative Commons Attribution-Share Alike 3.0 license published by Creative Commons Corporation, a not-for-profit corporation with a principal place of business in San Francisco, California, as well as future copyleft versions of that license published by that same organization.

    “Incorporate” means to publish or republish a Document, in whole or in part, as part of another Document.

    An MMC is “eligible for relicensing” if it is licensed under this License, and if all works that were first published under this License somewhere other than this MMC, and subsequently incorporated in whole or in part into the MMC, (1) had no cover texts or invariant sections, and (2) were thus incorporated prior to November 1, 2008.

    The operator of an MMC Site may republish an MMC contained in the site under CC-BY-SA on the same site at any time before August 1, 2009, provided the MMC is eligible for relicensing.

ADDENDUM: How to use this License for your documents

To use this License in a document you have written, include a copy of the License in the document and put the following copyright and license notices just after the title page:

       Copyright (C)  year  your name.
       Permission is granted to copy, distribute and/or modify this document
       under the terms of the GNU Free Documentation License, Version 1.3
       or any later version published by the Free Software Foundation;
       with no Invariant Sections, no Front-Cover Texts, and no Back-Cover
       Texts.  A copy of the license is included in the section entitled ``GNU
       Free Documentation License''.

If you have Invariant Sections, Front-Cover Texts and Back-Cover Texts, replace the “with...Texts.” line with this:

         with the Invariant Sections being list their titles, with
         the Front-Cover Texts being list, and with the Back-Cover Texts
         being list.

If you have Invariant Sections without Cover Texts, or some other combination of the three, merge those two alternatives to suit the situation.

If your document contains nontrivial examples of program code, we recommend releasing these examples in parallel under your choice of free software license, such as the GNU General Public License, to permit their use in free software.

Appendix D An entry for each concept

• Binary heap container: heap
• Binary tree container: btree
• Circular list: circular
• FDL, GNU Free Documentation License: Documentation License
• Hash table container: hash
• Heap container: heap
• Map container: map
• Set iterators: map set
• Vector container: vector

Appendix E An entry for each function

• *: map ops
• ucl_ascii_alloc: memory ascii
• ucl_ascii_clean_memory: memory ascii
• ucl_ascii_const: memory ascii
• ucl_ascii_free: memory ascii
• ucl_ascii_from_block: memory ascii
• ucl_ascii_is_null: memory ascii
• ucl_ascii_is_terminated: memory ascii
• ucl_ascii_realloc: memory ascii
• ucl_ascii_reset: memory ascii
• ucl_ascii_set: memory ascii
• ucl_ascii_terminate: memory ascii
• ucl_block_alloc: memory blocks
• ucl_block_clean_memory: memory blocks
• ucl_block_difference: memory blocks
• ucl_block_free: memory blocks
• ucl_block_from_ascii: memory ascii
• ucl_block_is_null: memory blocks
• ucl_block_realloc: memory blocks
• ucl_block_reset: memory blocks
• ucl_block_set: memory blocks
• ucl_block_shift: memory blocks
• ucl_block_shift_x: memory blocks
• ucl_bst_delete: btree bst
• ucl_bst_find: btree bst
• ucl_bst_insert: btree bst
• ucl_btree_avl_depth: btree avl
• ucl_btree_avl_factor: btree avl
• ucl_btree_avl_is_balanced: btree avl
• ucl_btree_avl_is_correct: btree avl
• ucl_btree_avl_rot_left: btree avl
• ucl_btree_avl_rot_left_right: btree avl
• ucl_btree_avl_rot_right: btree avl
• ucl_btree_avl_rot_right_left: btree avl
• ucl_btree_clean: btree removing
• ucl_btree_data: btree inspection
• ucl_btree_depth: btree inspection
• ucl_btree_detach_bro: btree removing
• ucl_btree_detach_dad: btree removing
• ucl_btree_detach_son: btree removing
• ucl_btree_find_deepest_bro: btree visitors
• ucl_btree_find_deepest_son: btree visitors
• ucl_btree_find_leftmost: btree visitors
• ucl_btree_find_rightmost: btree visitors
• ucl_btree_find_root: btree visitors
• ucl_btree_find_value: btree find
• ucl_btree_first_inorder: btree inorder iteration
• ucl_btree_first_inorder_backward: btree inorder iteration
• ucl_btree_first_levelorder: btree breadth first
• ucl_btree_first_levelorder_backward: btree breadth first
• ucl_btree_first_postorder: btree postorder iteration
• ucl_btree_first_postorder_backward: btree postorder iteration
• ucl_btree_first_preorder: btree preorder iteration
• ucl_btree_first_preorder_backward: btree preorder iteration
• ucl_btree_is_leaf: btree inspection
• ucl_btree_is_root: btree inspection
• ucl_btree_iterator_inorder: btree inorder iteration
• ucl_btree_iterator_inorder_backward: btree inorder iteration
• ucl_btree_iterator_levelorder: btree breadth first
• ucl_btree_iterator_levelorder_backward: btree breadth first
• ucl_btree_iterator_postorder: btree postorder iteration
• ucl_btree_iterator_postorder_backward: btree postorder iteration
• ucl_btree_iterator_preorder: btree preorder iteration
• ucl_btree_iterator_preorder_backward: btree preorder iteration
• ucl_btree_range_iterator_inorder: btree inorder iteration
• ucl_btree_range_iterator_inorder_backward: btree inorder iteration
• ucl_btree_range_iterator_postorder: btree postorder iteration
• ucl_btree_range_iterator_postorder_backward: btree postorder iteration
• ucl_btree_range_iterator_preorder: btree preorder iteration
• ucl_btree_range_iterator_preorder_backward: btree preorder iteration
• ucl_btree_ref_bro: btree inspection
• ucl_btree_ref_dad: btree inspection
• ucl_btree_ref_son: btree inspection
• ucl_btree_set_bro: btree creation
• ucl_btree_set_dad: btree creation
• ucl_btree_set_dadbro: btree creation
• ucl_btree_set_dadson: btree creation
• ucl_btree_set_dadsonbro: btree creation
• ucl_btree_set_son: btree creation
• ucl_btree_step_inorder: btree inorder iteration
• ucl_btree_step_inorder_backward: btree inorder iteration
• ucl_btree_step_levelorder: btree breadth first
• ucl_btree_step_levelorder_backward: btree breadth first
• ucl_btree_step_postorder: btree postorder iteration
• ucl_btree_step_postorder_backward: btree postorder iteration
• ucl_btree_step_preorder: btree preorder iteration
• ucl_btree_step_preorder_backward: btree preorder iteration
• ucl_btree_subtree_iterator_inorder: btree inorder iteration
• ucl_btree_subtree_iterator_inorder_backward: btree inorder iteration
• ucl_btree_subtree_iterator_postorder: btree postorder iteration
• ucl_btree_subtree_iterator_postorder_backward: btree postorder iteration
• ucl_btree_subtree_iterator_preorder: btree preorder iteration
• ucl_btree_subtree_iterator_preorder_backward: btree preorder iteration
• ucl_btree_swap: btree swap
• ucl_btree_swap_no_meta: btree swap
• ucl_btree_swap_out: btree swap
• ucl_callback_apply: typedefs callback
• ucl_callback_apply_fun_t: typedefs callback
• ucl_callback_eval_thunk: typedefs callback
• ucl_callback_fun_t: typedefs callback
• ucl_callback_is_present: typedefs callback
• ucl_callback_set_application_function: typedefs callback
• ucl_circular_backward: circular moving
• ucl_circular_constructor: circular creation
• ucl_circular_current: circular ops
• ucl_circular_destructor: circular creation
• ucl_circular_extract: circular removing
• ucl_circular_find: circular search
• ucl_circular_forward: circular moving
• ucl_circular_insert: circular adding
• ucl_circular_set_compar: circular search
• ucl_circular_size: circular ops
• ucl_compare_int_fun: misc compar
• ucl_compare_int_pointer_fun: misc compar
• ucl_compare_string_fun: misc compar
• ucl_compare_unsigned_int_fun: misc compar
• ucl_comparison_fun_t: typedefs compar
• ucl_free: memory functions
• ucl_graph_dfs: graph dfs api
• ucl_graph_dfs_directed: graph dfs api
• ucl_graph_dfs_finalise_handle: graph dfs api
• ucl_graph_dfs_initialise_handle: graph dfs api
• ucl_graph_erase_node_destroy_links: graph extract
• ucl_graph_first_input_link: graph link iter
• UCL_GRAPH_FIRST_INPUT_LINK_LOOP: graph extract
• ucl_graph_first_output_link: graph link iter
• UCL_GRAPH_FIRST_OUTPUT_LINK_LOOP: graph extract
• ucl_graph_input_link: graph link iter
• UCL_GRAPH_INPUT_LINKS_LOOP: graph link iter
• ucl_graph_last_input_link: graph link iter
• ucl_graph_last_output_link: graph link iter
• ucl_graph_link: graph insert
• ucl_graph_link_get_value: graph value
• ucl_graph_link_set_value: graph value
• ucl_graph_merge_upon_input_link: graph merge
• ucl_graph_merge_upon_output_link: graph merge
• ucl_graph_next_input_link: graph link iter
• ucl_graph_next_output_link: graph link iter
• ucl_graph_node_get_mark: graph value
• ucl_graph_node_get_value: graph value
• ucl_graph_node_set_mark: graph value
• ucl_graph_node_set_value: graph value
• ucl_graph_nodes_are_connected: graph insert
• ucl_graph_nodes_are_linked: graph insert
• ucl_graph_nodes_doubly_linked: graph insert
• ucl_graph_number_of_input_links: graph ops
• ucl_graph_number_of_output_links: graph ops
• ucl_graph_output_link: graph link iter
• UCL_GRAPH_OUTPUT_LINKS_LOOP: graph link iter
• ucl_graph_prev_input_link: graph link iter
• ucl_graph_prev_output_link: graph link iter
• ucl_graph_unlink: graph extract
• ucl_hash_average_search_distance: hash ops
• ucl_hash_bucket_chain_length: hash ops
• ucl_hash_enlarge: hash resizing
• ucl_hash_extract: hash deletion
• ucl_hash_find: hash ops
• ucl_hash_first: hash ops
• ucl_hash_fun_t: typedefs hash
• ucl_hash_initialise: hash creation
• ucl_hash_insert: hash insertion
• ucl_hash_iterator: hash iterator
• ucl_hash_number_of_buckets: hash ops
• ucl_hash_number_of_used_buckets: hash ops
• ucl_hash_restrict: hash resizing
• ucl_hash_size: hash ops
• ucl_hash_string_fun: hash functions
• ucl_heap_extract: heap deletion
• ucl_heap_initialise: heap creation
• ucl_heap_insert: heap insertion
• ucl_heap_merge: heap ops
• ucl_heap_root: heap ops
• ucl_heap_size: heap ops
• ucl_interface_major_version: misc version
• ucl_interface_minor_version: misc version
• ucl_iterator_more: iterators
• ucl_iterator_next: iterators
• ucl_iterator_ptr: iterators
• ucl_list_caaar: list visit
• ucl_list_caadr: list visit
• ucl_list_caar: list visit
• ucl_list_cadar: list visit
• ucl_list_caddr: list visit
• ucl_list_cadr: list visit
• ucl_list_car: list visit
• ucl_list_cdaar: list visit
• ucl_list_cdadr: list visit
• ucl_list_cdar: list visit
• ucl_list_cddar: list visit
• ucl_list_cdddr: list visit
• ucl_list_cddr: list visit
• ucl_list_cdr: list visit
• ucl_list_first: list visit
• ucl_list_for_each: list ops
• ucl_list_last: list visit
• ucl_list_length: list ops
• ucl_list_map: list ops
• ucl_list_popback: list deletion
• ucl_list_popfront: list deletion
• ucl_list_prev: list visit
• ucl_list_ref: list visit
• ucl_list_remove: list deletion
• ucl_list_reverse: list ops
• ucl_list_set_car: list cons
• ucl_list_set_cdr: list cons
• ucl_malloc: memory functions
• ucl_map_count: map ops
• ucl_map_delete: map deletion
• ucl_map_depth: map ops
• ucl_map_find: map ops
• ucl_map_find_node: map ops
• ucl_map_find_or_next: map ops
• ucl_map_find_or_prev: map ops
• ucl_map_first: map ops
• ucl_map_initialise: map creation
• ucl_map_insert: map insertion
• ucl_map_iterator_complintersect: map set
• ucl_map_iterator_inorder: map iterators
• ucl_map_iterator_intersection: map set
• ucl_map_iterator_levelorder: map iterators
• ucl_map_iterator_postorder: map iterators
• ucl_map_iterator_preorder: map iterators
• ucl_map_iterator_subtraction: map set
• ucl_map_iterator_union: map set
• ucl_map_last: map ops
• ucl_map_lower_bound: map iterators
• ucl_map_next: map ops
• ucl_map_prev: map ops
• ucl_map_size: map ops
• ucl_map_upper_bound: map iterators
• ucl_memory_alloc: memory functions
• ucl_memory_alloc_fun_t: memory typedefs
• ucl_node_getkey_fun_t: typedefs nodes
• UCL_NODE_SIZE: btree typedefs
• ucl_quicksort: misc sort
• ucl_range_equal: typedefs ranges
• ucl_range_is_empty: typedefs ranges
• ucl_range_max: typedefs ranges
• ucl_range_min: typedefs ranges
• ucl_range_set_max_size: typedefs ranges
• ucl_range_set_min_max: typedefs ranges
• ucl_range_set_min_size: typedefs ranges
• ucl_range_set_size_on_max: typedefs ranges
• ucl_range_set_size_on_min: typedefs ranges
• ucl_range_size: typedefs ranges
• ucl_range_value_is_in: typedefs ranges
• ucl_range_value_is_out: typedefs ranges
• ucl_realloc: memory functions
• ucl_struct_alloc: memory macros
• ucl_struct_clean: memory macros
• ucl_struct_reset: memory macros
• ucl_tree_extract_dad: tree removing
• ucl_tree_extract_next: tree removing
• ucl_tree_extract_prev: tree removing
• ucl_tree_extract_son: tree removing
• ucl_tree_has_dad: tree testing
• ucl_tree_has_next: tree testing
• ucl_tree_has_prev: tree testing
• ucl_tree_has_son: tree testing
• ucl_tree_insert_dad: tree insertion
• ucl_tree_insert_next: tree insertion
• ucl_tree_insert_prev: tree insertion
• ucl_tree_insert_son: tree insertion
• ucl_tree_is_bro: tree testing
• ucl_tree_is_dad: tree testing
• ucl_tree_iterator_inorder: tree iterators
• ucl_tree_iterator_postorder: tree iterators
• ucl_tree_iterator_preorder: tree iterators
• ucl_tree_ref_dad: tree relatives
• ucl_tree_ref_first: tree relatives
• ucl_tree_ref_last: tree relatives
• ucl_tree_ref_next: tree relatives
• ucl_tree_ref_prev: tree relatives
• ucl_tree_ref_son: tree relatives
• ucl_tree_set_dadson: tree creation
• ucl_tree_set_next: tree creation
• ucl_tree_set_prev: tree creation
• ucl_tree_set_prevnext: tree creation
• ucl_vector_alloc: vector creation
• ucl_vector_append: vector high append
• ucl_vector_append_block: vector high append
• ucl_vector_append_more: vector high append
• ucl_vector_append_more_from_array: vector high append
• ucl_vector_append_range: vector high append
• ucl_vector_back: vector indexes i2p
• ucl_vector_binary_search: vector find
• ucl_vector_block_from_range: vector indexes block
• ucl_vector_clean: vector creation
• ucl_vector_compare: vector high compare
• ucl_vector_compare_range: vector high compare
• ucl_vector_copy_range: vector high access
• ucl_vector_decrement_slot: vector ops
• UCL_VECTOR_DEFAULT_PAD: vector creation
• UCL_VECTOR_DEFAULT_STEP_DOWN: vector creation
• UCL_VECTOR_DEFAULT_STEP_UP: vector creation
• ucl_vector_enlarge: vector memory enlarge
• ucl_vector_enlarge_for_range: vector memory enlarge
• ucl_vector_enlarge_for_slots: vector memory enlarge
• ucl_vector_enlarged_size: vector memory enlarge
• ucl_vector_equal: vector high compare
• ucl_vector_equal_range: vector high compare
• ucl_vector_erase: vector removing
• ucl_vector_erase_range: vector high erase
• ucl_vector_find: vector find
• ucl_vector_for_each: vector high apply
• ucl_vector_for_each_in_range: vector high apply
• ucl_vector_for_each_multiple: vector high apply
• ucl_vector_for_each_multiple_from_array: vector high apply
• ucl_vector_free: vector creation
• ucl_vector_front: vector indexes i2p
• ucl_vector_get_block: vector high access
• ucl_vector_get_data_block: vector ops
• ucl_vector_get_free_block_at_beginning: vector ops
• ucl_vector_get_free_block_at_end: vector ops
• ucl_vector_get_memory_block: vector ops
• ucl_vector_increment_slot: vector ops
• ucl_vector_index_is_valid: vector indexes validation
• ucl_vector_index_is_valid_new: vector indexes validation
• ucl_vector_index_to_new_slot: vector indexes i2p
• ucl_vector_index_to_slot: vector indexes i2p
• ucl_vector_initialise_config: vector creation
• ucl_vector_initialise_config_buffer: vector creation
• ucl_vector_initialise_config_dfs: vector creation
• ucl_vector_initialise_config_hash: vector creation
• ucl_vector_insert: vector adding
• ucl_vector_insert_block: vector high insert
• ucl_vector_insert_range: vector high insert
• ucl_vector_insert_sort: vector adding
• ucl_vector_insert_vector: vector high insert
• ucl_vector_iterator_backward: vector iteration
• ucl_vector_iterator_forward: vector iteration
• ucl_vector_iterator_range_backward: vector iteration
• ucl_vector_iterator_range_forward: vector iteration
• ucl_vector_last_index: vector indexes p2i
• ucl_vector_map: vector high apply
• ucl_vector_map_multiple: vector high apply
• ucl_vector_map_multiple_from_array: vector high apply
• ucl_vector_map_range: vector high apply
• ucl_vector_mark_all_slots_as_used: vector creation
• ucl_vector_mark_allocated_range_as_used: vector creation
• ucl_vector_mark_as_used: vector ops
• ucl_vector_number_of_free_slots: vector memory misc
• ucl_vector_number_of_padding_slots: vector creation
• ucl_vector_number_of_step_down_slots: vector creation
• ucl_vector_number_of_step_up_slots: vector creation
• ucl_vector_pointer_is_valid_slot: vector indexes validation
• ucl_vector_pop_back: vector high stack
• ucl_vector_pop_front: vector high stack
• ucl_vector_push_back: vector high stack
• ucl_vector_push_front: vector high stack
• ucl_vector_quick_sort: vector ops
• ucl_vector_range: vector indexes range
• ucl_vector_range_from_block: vector indexes block
• ucl_vector_range_from_end_to_position: vector indexes range
• ucl_vector_range_from_end_with_span: vector indexes range
• ucl_vector_range_from_position_to_end: vector indexes range
• ucl_vector_range_is_valid: vector indexes range
• ucl_vector_register_allocator: vector memory misc
• ucl_vector_reset: vector creation
• ucl_vector_restrict: vector memory restrict
• ucl_vector_restricted_size: vector memory restrict
• ucl_vector_running: vector creation
• ucl_vector_set_block: vector high access
• ucl_vector_set_compar: vector creation
• ucl_vector_set_memory_to_zero: vector memory misc
• ucl_vector_size: vector ops
• ucl_vector_slot_dimension: vector ops
• ucl_vector_slot_to_index: vector indexes p2i
• ucl_vector_sort_find: vector find
• ucl_vector_sorted: vector ops
• ucl_vector_swallow_block: vector creation
• ucl_vector_update_number_of_padding_slots: vector creation
• ucl_vector_update_number_of_step_down_slots: vector creation
• ucl_vector_update_number_of_step_up_slots: vector creation
• ucl_vector_will_enlarge: vector memory enlarge
• ucl_vector_will_restrict: vector memory restrict
• ucl_version: misc version
• ucl_version_interface_age: version
• ucl_version_interface_current: version
• ucl_version_interface_revision: version
• ucl_version_string: version