gwenhywfar 4.0.3

Macros For Typesafe Tree Handling

Internal Functions

All functions and structs within this group should be considered internal. They just implement the functionality behind the typesafe list macros (see GWEN_TREE_FUNCTION_LIB_DEFS and following).
typedef struct GWEN_TREE GWEN_TREE
typedef struct GWEN_TREE_ELEMENT GWEN_TREE_ELEMENT
GWENHYWFAR_API GWEN_TREEGWEN_Tree_new ()
GWENHYWFAR_API void GWEN_Tree_free (GWEN_TREE *l)
GWENHYWFAR_API int GWEN_Tree_GetCount (const GWEN_TREE *l)
GWENHYWFAR_API void GWEN_Tree_Add (GWEN_TREE *l, GWEN_TREE_ELEMENT *el)
GWENHYWFAR_API void GWEN_Tree_Insert (GWEN_TREE *l, GWEN_TREE_ELEMENT *el)
GWENHYWFAR_API void GWEN_Tree_Del (GWEN_TREE_ELEMENT *el)
GWENHYWFAR_API void GWEN_Tree_AddList (GWEN_TREE *dest, GWEN_TREE *l)
GWENHYWFAR_API void GWEN_Tree_AddChild (GWEN_TREE_ELEMENT *where, GWEN_TREE_ELEMENT *el)
GWENHYWFAR_API void GWEN_Tree_InsertChild (GWEN_TREE_ELEMENT *where, GWEN_TREE_ELEMENT *el)
GWENHYWFAR_API void * GWEN_Tree_GetFirst (const GWEN_TREE *l)
GWENHYWFAR_API void * GWEN_Tree_GetLast (const GWEN_TREE *l)
GWENHYWFAR_API GWEN_TREE_ELEMENTGWEN_TreeElement_new (void *d)
GWENHYWFAR_API void GWEN_TreeElement_free (GWEN_TREE_ELEMENT *el)
GWENHYWFAR_API void * GWEN_TreeElement_GetPrevious (const GWEN_TREE_ELEMENT *el)
GWENHYWFAR_API void * GWEN_TreeElement_GetNext (const GWEN_TREE_ELEMENT *el)
GWENHYWFAR_API void * GWEN_TreeElement_GetBelow (const GWEN_TREE_ELEMENT *el)
GWENHYWFAR_API void * GWEN_TreeElement_GetFirstChild (const GWEN_TREE_ELEMENT *el)
GWENHYWFAR_API void * GWEN_TreeElement_GetLastChild (const GWEN_TREE_ELEMENT *el)
GWENHYWFAR_API void * GWEN_TreeElement_GetParent (const GWEN_TREE_ELEMENT *el)
GWENHYWFAR_API uint32_t GWEN_TreeElement_GetChildrenCount (const GWEN_TREE_ELEMENT *el)

Typesafe Macros

#define GWEN_TREE_ELEMENT(t)   GWEN_TREE_ELEMENT *_tree_element;
#define GWEN_TREE_FUNCTION_LIB_DEFS_CONST(t, pr, decl)
#define GWEN_TREE_FUNCTION_LIB_DEFS_NOCONST(t, pr, decl)
#define GWEN_TREE_FUNCTION_DEFS_CONST(t, pr)   GWEN_TREE_FUNCTION_LIB_DEFS_CONST(t, pr, GWEN_DUMMY_EMPTY_ARG)
#define GWEN_TREE_FUNCTION_DEFS_NOCONST(t, pr)   GWEN_TREE_FUNCTION_LIB_DEFS_NOCONST(t, pr, GWEN_DUMMY_EMPTY_ARG)
#define GWEN_TREE_FUNCTION_LIB_DEFS(t, pr, decl)
#define GWEN_TREE_FUNCTION_DEFS(t, pr)   GWEN_TREE_FUNCTION_LIB_DEFS(t, pr, GWEN_DUMMY_EMPTY_ARG)
#define GWEN_TREE_FUNCTIONS(t, pr)
#define GWEN_TREE_INIT(t, element)   element->_tree_element=GWEN_TreeElement_new(element);
#define GWEN_TREE_FINI(t, element)

Detailed Description

The macros of this group facilitates typesafe use of trees.

Let's assume you have a structure type called MYSTRUCT and you want to manage lists of them. Let's further assume that you want the functions dealing with that struct have prefixes like MyStruct (as in MyStruct_new) The header file would look like this:

 / * mystruct.h * /

 #ifndef MYSTRUCT_H
 #define MYSTRUCT_H

 typedef struct MYSTRUCT MYSTRUCT;

 GWEN_TREE_FUNCTION_DEFS(MYSTRUCT, MyStruct);

 struct MYSTRUCT {
   GWEN_TREE_ELEMENT(MYSTRUCT);
   int myData;
 }


 MYSTRUCT *MyStruct_new(int myData);
 void MyStruct_free(MYSTRUCT *myStruct);

 #endif

This defines all necessary data and function prototypes needed for list management.

The code file would look quite similar to the following:

 / * mystruct.c * /

 GWEN_TREE_FUNCTIONS(MYSTRUCT, MyStruct)

 MYSTRUCT *MyStruct_new(int myData) {
   MYSTRUCT *pMyStruct;

   pMyStruct=(MYSTRUCT*)malloc(sizeof(MYSTRUCT));
   memset(pMyStruct, 0, sizeof(MYSTRUCT));

   GWEN_TREE_INIT(MYSTRUCT, pMyStruct)

   pMyStruct->myData=myData;
   return pMyStruct;
 }

 void MyStruct_free(MYSTRUCT *pMyStruct) {
   if (pMyStruct) {
     pMyStruct->myData=0;

     GWEN_TREE_FINI(MYSTRUCT, pMyStruct)

     free(pMyStruct);
   }
 }

Please note the three macros used in the code file:

Note: When writing these macro code lines, the original ISO C89 standard for the C language does not allow terminating the macro statement with a semicolon ';'. Any recent compiler will probably silently ignore such an extra ';', but you should be aware that this can cause problems once one of your users tries to compile this with a different compiler. Therefore these code lines should end directly with the closing parentheses.

The list management code assumes that there is a function called (in this example) MyStruct_free() (or generally: TYPEPREFIX_free). This is used when destroying a list of MYSTRUCT elements. In this case all elements still enlisted are destroyed upon destruction of the list.


Define Documentation

#define GWEN_TREE_ELEMENT (   t)    GWEN_TREE_ELEMENT *_tree_element;

Use this inside the declaration of a struct for which you want to create lists.

Definition at line 278 of file tree.h.

#define GWEN_TREE_FINI (   t,
  element 
)
Value:
if (element && element->_tree_element) { \
    GWEN_TreeElement_free(element->_tree_element); \
    element->_tree_element=0; \
  }

Use this in your code file (*.c) inside the fini code for the struct you want to use in lists (in GWEN these are the functions which end with "_free".

Definition at line 554 of file tree.h.

Referenced by GWEN_ProgressData_free(), GWEN_Widget_free(), and HtmlObject_free().

#define GWEN_TREE_FUNCTION_DEFS (   t,
  pr 
)    GWEN_TREE_FUNCTION_LIB_DEFS(t, pr, GWEN_DUMMY_EMPTY_ARG)

This macro should be used in applications, not in libraries. In libraries please use the macro GWEN_TREE_FUNCTION_LIB_DEFS.

Definition at line 384 of file tree.h.

#define GWEN_TREE_FUNCTION_DEFS_CONST (   t,
  pr 
)    GWEN_TREE_FUNCTION_LIB_DEFS_CONST(t, pr, GWEN_DUMMY_EMPTY_ARG)

Definition at line 321 of file tree.h.

#define GWEN_TREE_FUNCTION_DEFS_NOCONST (   t,
  pr 
)    GWEN_TREE_FUNCTION_LIB_DEFS_NOCONST(t, pr, GWEN_DUMMY_EMPTY_ARG)

Definition at line 324 of file tree.h.

#define GWEN_TREE_FUNCTION_LIB_DEFS (   t,
  pr,
  decl 
)
Value:

Use this in public header files to define some prototypes for list functions. Let's assume the type of your list elements is "MYTYPE" and you want to use the prefix "MyType_" for the list functions. The following function prototypes will then be created:

  • void MyType_Tree_Add(MYTYPE *element, MYTYPE_TREE *list);
    Adds (appends) a MYTYPE struct at the end of the given list. (We apologize for the unusual argument order here.)
  • void MyType_Tree_Del(MYTYPE *element);
    Removes a MyType struct from the list it is enlisted to.
  • MYTYPE *MyType_Tree_First(MYTYPE *element);
    Returns the first element of the given list.
  • MYTYPE* MyType_Tree_Next(const MYTYPE *element);
    Returns the next list element to the given one (the successor) in its list.
  • MYTYPE* MyType_Tree_Previous(const MYTYPE *element);
    Returns the previous list element to the given one (the predecessor) in its list.
  • void MyType_Tree_Clear(MYTYPE *element);
    Frees all entries of the given list. This function assumes that there is a function Mytype_free().
  • MYTYPE_TREE *MyType_Tree_new();
    Creates a new list of elements of MYTYPE type.
  • void MyType_Tree_free(MYTYPE_TREE *l);
    Clears and frees a list of elements of MYTYPE type. All objects inside the list are freed.

Definition at line 375 of file tree.h.

#define GWEN_TREE_FUNCTION_LIB_DEFS_CONST (   t,
  pr,
  decl 
)
Value:
typedef GWEN_TREE t##_TREE; \
  \
  decl t* pr##_Tree_GetFirst(const t##_TREE *l); \
  decl t* pr##_Tree_GetLast(const t##_TREE *l); \
  decl t* pr##_Tree_GetNext(const t *element); \
  decl t* pr##_Tree_GetPrevious(const t *element); \
  decl t* pr##_Tree_GetBelow(const t *element); \
  decl uint32_t pr##_Tree_GetCount(const t##_TREE *l); \
  decl int pr##_Tree_HasElement(const t##_TREE *l, const t *element); \
  decl t* pr##_Tree_GetFirstChild(const t *element); \
  decl t* pr##_Tree_GetLastChild(const t *element); \
  decl uint32_t pr##_Tree_GetChildrenCount(const t *element); \
  decl t* pr##_Tree_GetParent(const t *element);

Use this macro in your public header files to export only list functions which do not modify a list. This allows your code to return lists which can not be modified by callers. It also prevents callers from creating their own lists (this is sometimes needed).

Definition at line 287 of file tree.h.

#define GWEN_TREE_FUNCTION_LIB_DEFS_NOCONST (   t,
  pr,
  decl 
)
Value:
typedef GWEN_TREE_ELEMENT t##_TREE_ELEMENT; \
  \
  decl void pr##_Tree_Clear(t##_TREE *l); \
  decl t##_TREE* pr##_Tree_new(); \
  decl void pr##_Tree_free(t##_TREE *l); \
  decl void pr##_Tree_AddList(t##_TREE *dst, t##_TREE *l); \
  decl void pr##_Tree_Add(t##_TREE *list, t *element); \
  decl void pr##_Tree_Insert(t##_TREE *list, t *element); \
  decl void pr##_Tree_Del(t *element); \
  \
  decl void pr##_Tree_AddChild(t *where, t *element); \
  decl void pr##_Tree_InsertChild(t *where, t *element); \
  \
  decl int pr##_Tree_HasChildElement(const t *who, const t *element); \
  decl void pr##_Tree_ClearChildren(t *element); \

Definition at line 303 of file tree.h.

#define GWEN_TREE_FUNCTIONS (   t,
  pr 
)

Use this inside your code files (*.c). Actually implements the functions for which the prototypes have been defined via GWEN_TREE_FUNCTION_DEFS.

Definition at line 393 of file tree.h.

#define GWEN_TREE_INIT (   t,
  element 
)    element->_tree_element=GWEN_TreeElement_new(element);

Use this in your code file (*.c) inside the init code for the struct you want to use in lists (in GWEN these are the functions which end with "_new".

Definition at line 545 of file tree.h.

Referenced by GWEN_ProgressData_new(), GWEN_Widget_new(), and HtmlObject_new().


Typedef Documentation

typedef struct GWEN_TREE GWEN_TREE

Definition at line 155 of file tree.h.

Definition at line 156 of file tree.h.


Function Documentation

GWENHYWFAR_API void GWEN_Tree_Add ( GWEN_TREE l,
GWEN_TREE_ELEMENT el 
)

Adds (appends) a toplevel tree element. (This operation is also called "append" or "push_back" elsewhere.)

Definition at line 62 of file tree.c.

References DBG_ERROR, GWEN_LOGDOMAIN, and NULL.

Referenced by GWEN_Tree_AddList().

GWENHYWFAR_API void GWEN_Tree_AddChild ( GWEN_TREE_ELEMENT where,
GWEN_TREE_ELEMENT el 
)

Add a child below the given element.

Definition at line 166 of file tree.c.

References DBG_ERROR, and GWEN_LOGDOMAIN.

GWENHYWFAR_API void GWEN_Tree_AddList ( GWEN_TREE dest,
GWEN_TREE l 
)

Adds (appends) the second list to the end of the first list. (This operation is also called "append" or "concatenate" elsewhere.) The second list will be empty upon return.

Definition at line 87 of file tree.c.

References GWEN_Tree_Add(), and GWEN_Tree_Del().

GWENHYWFAR_API void GWEN_Tree_Del ( GWEN_TREE_ELEMENT el)

Deletes (removes) a tree element from the tree it used to belong to. The tree element is not free'd or anything, it is only removed from the list it used to belong to. (This operation is also called "remove" or "unlink" elsewhere.)

Definition at line 123 of file tree.c.

References DBG_ERROR, GWEN_LOGDOMAIN, and NULL.

Referenced by GWEN_Tree_AddList(), and GWEN_TreeElement_free().

GWENHYWFAR_API void GWEN_Tree_free ( GWEN_TREE l)

Free (delete) an existing list. The list elements are untouched by this function; they need to be freed beforehand.

Definition at line 47 of file tree.c.

References GWEN_FREE_OBJECT.

GWENHYWFAR_API int GWEN_Tree_GetCount ( const GWEN_TREE l)

Returns the number of elements in this list. This value is cached in the list structure, so this function is a cheap function.

Definition at line 55 of file tree.c.

GWENHYWFAR_API void* GWEN_Tree_GetFirst ( const GWEN_TREE l)

Returns the data pointer of the first list element.

Definition at line 214 of file tree.c.

GWENHYWFAR_API void* GWEN_Tree_GetLast ( const GWEN_TREE l)

Returns the data pointer of the last list element.

Definition at line 222 of file tree.c.

GWENHYWFAR_API void GWEN_Tree_Insert ( GWEN_TREE l,
GWEN_TREE_ELEMENT el 
)

Inserts (prepends) a toplevel tree element at the beginning of the list. (This operation is also called "prepend" or "push_front" elsewhere.)

Definition at line 101 of file tree.c.

References DBG_ERROR, GWEN_LOGDOMAIN, and NULL.

GWENHYWFAR_API void GWEN_Tree_InsertChild ( GWEN_TREE_ELEMENT where,
GWEN_TREE_ELEMENT el 
)

Insert a child below the given element.

Definition at line 191 of file tree.c.

References DBG_ERROR, GWEN_LOGDOMAIN, and NULL.

GWENHYWFAR_API GWEN_TREE* GWEN_Tree_new ( )

Allocate (create) a new empty list.

Definition at line 39 of file tree.c.

References GWEN_NEW_OBJECT.

GWENHYWFAR_API void GWEN_TreeElement_free ( GWEN_TREE_ELEMENT el)

Free (delete) a list element structure.

Definition at line 243 of file tree.c.

References DBG_ERROR, GWEN_FREE_OBJECT, GWEN_LOGDOMAIN, and GWEN_Tree_Del().

GWENHYWFAR_API void* GWEN_TreeElement_GetBelow ( const GWEN_TREE_ELEMENT el)

Returns the element which is logically below the given one. The order of search is this:

  • first child of the given element
  • next neighbour of the given element
  • loop for every parent: check next neighbour of the given element's parent (if any)

Definition at line 273 of file tree.c.

References NULL.

GWENHYWFAR_API uint32_t GWEN_TreeElement_GetChildrenCount ( const GWEN_TREE_ELEMENT el)

Returns the number of children of the given element

Definition at line 317 of file tree.c.

GWENHYWFAR_API void* GWEN_TreeElement_GetFirstChild ( const GWEN_TREE_ELEMENT el)

Returns the first child of the given element.

Definition at line 293 of file tree.c.

References NULL.

GWENHYWFAR_API void* GWEN_TreeElement_GetLastChild ( const GWEN_TREE_ELEMENT el)

Returns the last child of the given element.

Definition at line 301 of file tree.c.

References NULL.

GWENHYWFAR_API void* GWEN_TreeElement_GetNext ( const GWEN_TREE_ELEMENT el)

Returns the data pointer of the list element that is the next one (successor) to the given one in its list. If there is no such prepending list element, returns NULL.

Definition at line 265 of file tree.c.

GWENHYWFAR_API void* GWEN_TreeElement_GetParent ( const GWEN_TREE_ELEMENT el)

Definition at line 309 of file tree.c.

References NULL.

GWENHYWFAR_API void* GWEN_TreeElement_GetPrevious ( const GWEN_TREE_ELEMENT el)

Returns the data pointer of the list element that is the previous (predecessor) to the given one in its list. If there is no such prepending list element, returns NULL.

Definition at line 257 of file tree.c.

GWENHYWFAR_API GWEN_TREE_ELEMENT* GWEN_TreeElement_new ( void *  d)

Allocate (create) a new list element structure.

Definition at line 232 of file tree.c.

References GWEN_NEW_OBJECT.