Provided by: tcl8.5-doc_8.5.11-1ubuntu1_all bug

NAME

       Tcl_ListObjAppendList,     Tcl_ListObjAppendElement,    Tcl_NewListObj,    Tcl_SetListObj,
       Tcl_ListObjGetElements,   Tcl_ListObjLength,   Tcl_ListObjIndex,   Tcl_ListObjReplace    -
       manipulate Tcl objects as lists

SYNOPSIS

       #include <tcl.h>

       int
       Tcl_ListObjAppendList(interp, listPtr, elemListPtr)

       int
       Tcl_ListObjAppendElement(interp, listPtr, objPtr)

       Tcl_Obj *
       Tcl_NewListObj(objc, objv)

       Tcl_SetListObj(objPtr, objc, objv)

       int
       Tcl_ListObjGetElements(interp, listPtr, objcPtr, objvPtr)

       int
       Tcl_ListObjLength(interp, listPtr, intPtr)

       int
       Tcl_ListObjIndex(interp, listPtr, index, objPtrPtr)

       int
       Tcl_ListObjReplace(interp, listPtr, first, count, objc, objv)

ARGUMENTS

       Tcl_Interp *interp (in)                   If an error occurs while converting an object to
                                                 be a list object, an error message  is  left  in
                                                 the interpreter's result object unless interp is
                                                 NULL.

       Tcl_Obj *listPtr (in/out)                 Points to the list object to be manipulated.  If
                                                 listPtr does not already point to a list object,
                                                 an attempt will be made to convert it to one.

       Tcl_Obj *elemListPtr (in/out)             For Tcl_ListObjAppendList, this points to a list
                                                 object  containing  elements to be appended onto
                                                 listPtr.   Each  element  of  *elemListPtr  will
                                                 become   a   new   element   of   listPtr.    If
                                                 *elemListPtr is not NULL and  does  not  already
                                                 point  to a list object, an attempt will be made
                                                 to convert it to one.

       Tcl_Obj *objPtr (in)                      For Tcl_ListObjAppendElement, points to the  Tcl
                                                 object  that  will  be appended to listPtr.  For
                                                 Tcl_SetListObj, this points to  the  Tcl  object
                                                 that   will   be  converted  to  a  list  object
                                                 containing  the  objc  elements  of  the   array
                                                 referenced by objv.

       int *objcPtr (in)                         Points  to location where Tcl_ListObjGetElements
                                                 stores the number of element objects in listPtr.

       Tcl_Obj ***objvPtr (out)                  A location where Tcl_ListObjGetElements stores a
                                                 pointer  to  an array of pointers to the element
                                                 objects of listPtr.

       int objc (in)                             The number of Tcl  objects  that  Tcl_NewListObj
                                                 will   insert   into  a  new  list  object,  and
                                                 Tcl_ListObjReplace  will  insert  into  listPtr.
                                                 For Tcl_SetListObj, the number of Tcl objects to
                                                 insert into objPtr.

       Tcl_Obj *const objv[] (in)                An array of pointers to objects.  Tcl_NewListObj
                                                 will insert these objects into a new list object
                                                 and Tcl_ListObjReplace will insert them into  an
                                                 existing  listPtr.   Each  object  will become a
                                                 separate list element.

       int *intPtr (out)                         Points  to  location   where   Tcl_ListObjLength
                                                 stores the length of the list.

       int index (in)                            Index  of the list element that Tcl_ListObjIndex
                                                 is to return.  The first element has index 0.

       Tcl_Obj **objPtrPtr (out)                 Points to place  where  Tcl_ListObjIndex  is  to
                                                 store  a  pointer  to the resulting list element
                                                 object.

       int first (in)                            Index  of  the  starting   list   element   that
                                                 Tcl_ListObjReplace  is  to  replace.  The list's
                                                 first element has index 0.

       int count (in)                            The number of elements  that  Tcl_ListObjReplace
                                                 is to replace.
_________________________________________________________________

DESCRIPTION

       Tcl  list objects have an internal representation that supports the efficient indexing and
       appending.  The procedures described in this man page are used to create,  modify,  index,
       and append to Tcl list objects from C code.

       Tcl_ListObjAppendList and Tcl_ListObjAppendElement both add one or more objects to the end
       of the list object referenced by listPtr.  Tcl_ListObjAppendList appends each  element  of
       the  list  object  referenced  by  elemListPtr  while Tcl_ListObjAppendElement appends the
       single object referenced by objPtr.  Both procedures will convert the object referenced by
       listPtr  to  a  list  object  if  necessary.   If  an error occurs during conversion, both
       procedures return TCL_ERROR and leave an error message in the interpreter's result  object
       if interp is not NULL.  Similarly, if elemListPtr does not already refer to a list object,
       Tcl_ListObjAppendList will attempt to convert it to one and  if  an  error  occurs  during
       conversion,  will  return TCL_ERROR and leave an error message in the interpreter's result
       object if interp is not NULL.  Both procedures invalidate any old string representation of
       listPtr  and,  if it was converted to a list object, free any old internal representation.
       Similarly, Tcl_ListObjAppendList frees any old internal representation of  elemListPtr  if
       it  converts  it  to  a  list  object.   After  appending  each  element  in  elemListPtr,
       Tcl_ListObjAppendList increments the element's reference  count  since  listPtr  now  also
       refers to it.  For the same reason, Tcl_ListObjAppendElement increments objPtr's reference
       count.  If no error occurs, the two procedures return TCL_OK after appending the objects.

       Tcl_NewListObj and Tcl_SetListObj create a new object or modify an existing object to hold
       the objc elements of the array referenced by objv where each element is a pointer to a Tcl
       object.  If objc is less than or equal to zero, they return  an  empty  object.   The  new
       object's  string  representation  is  left  invalid.   The  two  procedures  increment the
       reference counts of the elements in objc since the list object now refers  to  them.   The
       new list object returned by Tcl_NewListObj has reference count zero.

       Tcl_ListObjGetElements returns a count and a pointer to an array of the elements in a list
       object.  It returns the count by storing it in the address objcPtr.  Similarly, it returns
       the  array pointer by storing it in the address objvPtr.  The memory pointed to is managed
       by Tcl and should not be freed or written to by the caller. If the list  is  empty,  0  is
       stored  at  objcPtr  and  NULL  at  objvPtr.   If  listPtr  is  not already a list object,
       Tcl_ListObjGetElements will attempt to convert it to one;  if  the  conversion  fails,  it
       returns TCL_ERROR and leaves an error message in the interpreter's result object if interp
       is not NULL.  Otherwise it returns TCL_OK after storing the count and array pointer.

       Tcl_ListObjLength returns the number of elements in the list object referenced by listPtr.
       It  returns  this count by storing an integer in the address intPtr.  If the object is not
       already a list object, Tcl_ListObjLength will  attempt  to  convert  it  to  one;  if  the
       conversion  fails,  it  returns TCL_ERROR and leaves an error message in the interpreter's
       result object if interp is not NULL.  Otherwise it returns TCL_OK after storing the list's
       length.

       The  procedure  Tcl_ListObjIndex  returns  a pointer to the object at element index in the
       list referenced by listPtr.  It returns this object by storing a  pointer  to  it  in  the
       address  objPtrPtr.   If listPtr does not already refer to a list object, Tcl_ListObjIndex
       will attempt to convert it to one; if the  conversion  fails,  it  returns  TCL_ERROR  and
       leaves  an error message in the interpreter's result object if interp is not NULL.  If the
       index is out of range, that is, index is negative or greater than or equal to  the  number
       of  elements  in the list, Tcl_ListObjIndex stores a NULL in objPtrPtr and returns TCL_OK.
       Otherwise it returns TCL_OK after storing the element's  object  pointer.   The  reference
       count  for  the  list  element  is not incremented; the caller must do that if it needs to
       retain a pointer to the element.

       Tcl_ListObjReplace replaces zero or more elements of the list referenced by  listPtr  with
       the  objc  objects  in  the array referenced by objv.  If listPtr does not point to a list
       object, Tcl_ListObjReplace will attempt to convert it to one; if the conversion fails,  it
       returns TCL_ERROR and leaves an error message in the interpreter's result object if interp
       is not NULL.  Otherwise, it returns TCL_OK after replacing the objects.  If objv is  NULL,
       no  new  elements  are added.  If the argument first is zero or negative, it refers to the
       first element.  If first is greater than or equal to the number of elements in  the  list,
       then  no elements are deleted; the new elements are appended to the list.  count gives the
       number of elements to replace.  If count is zero or negative then no elements are deleted;
       the   new   elements   are   simply   inserted   before   the  one  designated  by  first.
       Tcl_ListObjReplace invalidates listPtr's old string representation.  The reference  counts
       of  any elements inserted from objv are incremented since the resulting list now refers to
       them.  Similarly, the reference counts for any replaced objects are decremented.

       Because Tcl_ListObjReplace combines both element insertion and deletion, it can be used to
       implement  a  number of list operations.  For example, the following code inserts the objc
       objects referenced by the array of object pointers objv just before the element  index  of
       the list referenced by listPtr:

              result = Tcl_ListObjReplace(interp, listPtr, index, 0,
                      objc, objv);

       Similarly, the following code appends the objc objects referenced by the array objv to the
       end of the list listPtr:

              result = Tcl_ListObjLength(interp, listPtr, &length);
              if (result == TCL_OK) {
                  result = Tcl_ListObjReplace(interp, listPtr, length, 0,
                          objc, objv);
              }

       The  count  list  elements  starting  at  first  can  be   deleted   by   simply   calling
       Tcl_ListObjReplace with a NULL objvPtr:

              result = Tcl_ListObjReplace(interp, listPtr, first, count,
                      0, NULL);

SEE ALSO

       Tcl_NewObj, Tcl_DecrRefCount, Tcl_IncrRefCount, Tcl_GetObjResult

KEYWORDS

       append,  index,  insert,  internal  representation,  length, list, list object, list type,
       object, object type, replace, string representation