File : asgc-ordered-dlist-fixed.adb
-- The Ada Structured Library - A set of container classes and general
-- tools for use with Ada95.
-- Copyright (C) 1998-1999 Corey Minyard (minyard@acm.org)
--
-- This library 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 2 of the License, or (at your
-- option) any later version.
--
-- This library 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 library; if not, write to the Free Software Foundation, Inc.,
-- 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
--
-- As a special exception, if other files instantiate generics from this
-- unit, or you link this unit with other files to produce an executable,
-- this unit does not by itself cause the resulting executable to be
-- covered by the GNU General Public License. This exception does not
-- however invalidate any other reasons why the executable file might be
-- covered by the GNU Public License.
--
with Ada.Unchecked_Deallocation;
package body Asgc.Ordered.Dlist.Fixed is
procedure Free_Iterator is new Ada.Unchecked_Deallocation(Iterator,
Iterator_Ptr);
------------------------------------------------------------------------
-- Allocate a free node for a new item in the list.
procedure Alloc_Node (O : in out Object'Class;
Item : out Node_Ref) is
begin
if (O.Free_List = Null_Node) then
raise Container_Full;
end if;
Item := O.Free_List;
O.Free_List := O.Data(Item).Next;
O.Data(Item).Next := Null_Node;
O.Data(Item).Prev := Null_Node;
end Alloc_Node;
------------------------------------------------------------------------
-- Free a node that is no longer in use.
procedure Free_Node (O : in out Object'Class;
Item : in out Node_Ref) is
begin
O.Data(Item).Next := O.Free_List;
O.Free_List := Item;
Item := Null_Node;
end Free_Node;
------------------------------------------------------------------------
-- Check that an object is valid, that is has not been freed. This is
-- not a perfect check, but will hopefully help find some bugs.
procedure Check_Object (O : in Object'Class) is
begin
if (O.Is_Free) then
raise Object_Free;
end if;
end Check_Object;
------------------------------------------------------------------------
-- Check that an iterator is valid. It must not have been freed, it
-- must be initialized, its object must be valid, and it must not have
-- been modified since the last time the iterator was positioned.
procedure Check_Iterator (Iter : in Iterator'Class) is
begin
if (Iter.Is_Free) then
raise Iterator_Free;
end if;
if (Iter.Robj = null) then
raise Invalid_Iterator;
end if;
Check_Object(Iter.Robj.all);
if (Iter.Update /= Iter.Robj.Update) then
raise Object_Updated;
end if;
if (Iter.Pos = Null_Node) then
raise Invalid_Iterator;
end if;
end Check_Iterator;
------------------------------------------------------------------------
-- Check that an iterator is valid. It must not have been freed, it
-- must be initialized, its object must be valid, and it must not have
-- been modified since the last time the iterator was positioned.
-- This routine allows the object to be empty.
procedure Check_Iterator_Empty_Ok (Iter : in Iterator'Class) is
begin
if (Iter.Is_Free) then
raise Iterator_Free;
end if;
if (Iter.Robj = null) then
raise Invalid_Iterator;
end if;
Check_Object(Iter.Robj.all);
if (Iter.Update /= Iter.Robj.Update) then
raise Object_Updated;
end if;
end Check_Iterator_Empty_Ok;
------------------------------------------------------------------------
-- Check an iterator, but don't bother checking its positions. This is
-- primarily for methods that set some the position of the iterator.
procedure Check_Iterator_No_Pos (Iter : in Iterator) is
begin
if (Iter.Is_Free) then
raise Iterator_Free;
end if;
if (Iter.Robj = null) then
raise Invalid_Iterator;
end if;
Check_Object(Iter.Robj.all);
end Check_Iterator_No_Pos;
------------------------------------------------------------------------
-- Delete the given reference and free it.
procedure Delete (O : in out Object'Class;
To_Free : in out Node_Ref;
Is_End : out End_Marker) is
Next_Val : Node_Ref;
begin
Next_Val := O.Data(To_Free).Next;
if (To_Free /= O.Head) then
-- Not deleting the first item, modify the prev's next ref.
O.Data(O.Data(To_Free).Prev).Next := Next_Val;
if (Next_Val = Null_Node) then
-- Deleting the tail, so handle that.
O.Tail := O.Data(To_Free).Prev;
Is_End := Past_End;
else
O.Data(Next_Val).Prev := O.Data(To_Free).Prev;
Is_End := Not_Past_End;
end if;
else
-- Deleting the first item, change the head.
O.Head := Next_Val;
if (Next_Val = Null_Node) then
-- Deleted the only item.
O.Tail := Null_Node;
Is_End := Past_End;
else
O.Data(Next_Val).Prev := Null_Node;
Is_End := Not_Past_End;
end if;
end if;
O.Update := O.Update + 1;
O.Count := O.Count - 1;
if (O.Cb /= null) then
Deleted(O.Cb, O, O.Data(To_Free).Val);
end if;
Free_Node(O, To_Free);
end Delete;
------------------------------------------------------------------------
-- Add the given item before Curr in the list.
procedure Add_Before (O : in out Object'Class;
Curr : in Node_Ref;
Val : in Contained_Type) is
New_Node : Node_Ref;
begin
Alloc_Node(O, New_Node);
O.Data(New_Node).Val := Val;
if (O.Tail = Null_Node) then
-- The list is empty, this becomes the only member.
O.Head := New_Node;
O.Tail := New_Node;
else
O.Data(New_Node).Next := Curr;
O.Data(New_Node).Prev := O.Data(Curr).Prev;
if (O.Head = Curr) then
-- If we are at the head, the new item becomes the new head.
O.Head := New_Node;
else
O.Data(O.Data(Curr).Prev).Next := New_Node;
end if;
O.Data(Curr).Prev := New_Node;
end if;
O.Count := O.Count + 1;
O.Update := O.Update + 1;
if (O.Cb /= null) then
Added(O.Cb, O, O.Data(New_Node).Val);
end if;
end Add_Before;
------------------------------------------------------------------------
-- Add the given item after Curr in the list.
procedure Add_After (O : in out Object'Class;
Curr : in Node_Ref;
Val : in Contained_Type) is
New_Node : Node_Ref;
begin
Alloc_Node(O, New_Node);
O.Data(New_Node).Val := Val;
if (O.Tail = Null_Node) then
-- The list is empty, this becomes the only member.
O.Head := New_Node;
O.Tail := New_Node;
else
O.Data(New_Node).Next := O.Data(Curr).Next;
O.Data(New_Node).Prev := Curr;
O.Data(Curr).Next := New_Node;
if (O.Tail = Curr) then
-- If we are at the tail, the new item becomes the new tail.
O.Tail := New_Node;
else
O.Data(O.Data(New_Node).Next).Prev := New_Node;
end if;
end if;
O.Count := O.Count + 1;
O.Update := O.Update + 1;
if (O.Cb /= null) then
Added(O.Cb, O, O.Data(New_Node).Val);
end if;
end Add_After;
------------------------------------------------------------------------
-- Using an object and an optional current location, seek to the given
-- location in the most efficient manner possible.
function Seek_To (O : in Object'Class;
Loc : in Positive;
Curr : in Node_Ref := Null_Node;
Curr_Loc : in Positive := 1)
return Node_Ref is
Retval : Node_Ref;
Diff : Integer;
Seek_Forward : Boolean;
begin
-- Start with trying the head node.
Retval := O.Head;
Diff := Loc - 1;
Seek_Forward := True;
if ((O.Count - Loc) < Diff) then
-- If the tail location is closer to the position, seek from there.
Diff := O.Count - Loc;
Seek_Forward := False;
Retval := O.Tail;
end if;
if (Curr /= Null_Node) then
-- Now check the passed in location and seek from there if it is
-- closer.
if ((Curr_Loc >= Loc) and ((Curr_Loc - Loc) < Diff)) then
Diff := Curr_Loc - Loc;
Seek_Forward := False;
Retval := Curr;
elsif ((Curr_Loc < Loc) and ((Loc - Curr_Loc) < Diff)) then
Diff := Loc - Curr_Loc;
Seek_Forward := True;
Retval := Curr;
end if;
end if;
-- Now do the seek.
if (Seek_Forward) then
for I in 1 .. Diff loop
Retval := O.Data(Retval).Next;
end loop;
else
for I in 1 .. Diff loop
Retval := O.Data(Retval).Prev;
end loop;
end if;
return Retval;
end Seek_To;
------------------------------------------------------------------------
-- This is a controlled type, so we have those methods to handle.
------------------------------------------------------------------------
procedure Initialize (O : in out Object) is
begin
-- Build the free list.
for I in 1 .. O.Size loop
O.Data(I).Next := O.Free_List;
O.Free_List := I;
end loop;
end Initialize;
------------------------------------------------------------------------
procedure Adjust (O : in out Object) is
New_List : Node_Ref := Null_Node;
New_Curr : Node_Ref;
Old_Curr : Node_Ref := O.Head;
begin
-- Call the Copied callback on each new element if the container has
-- a callback set.
if (O.Cb /= null) then
New_Curr := O.Head;
while (New_Curr /= Null_Node) loop
Copied(O.Cb, O, O.Data(New_Curr).Val);
New_Curr := O.Data(New_Curr).Next;
end loop;
end if;
end Adjust;
------------------------------------------------------------------------
procedure Finalize (O : in out Object) is
Curr : Node_Ref := O.Head;
Temp : Node_Ref;
begin
while (Curr /= Null_Node) loop
if (O.Cb /= null) then
Deleted(O.Cb, O, O.Data(Curr).Val);
end if;
Temp := O.Data(Curr).Next;
Curr := Temp;
end loop;
O.Is_Free := True;
end Finalize;
------------------------------------------------------------------------
procedure Finalize (Iter : in out Iterator) is
begin
Iter.Is_Free := True;
end Finalize;
------------------------------------------------------------------------
-- The functions that follow are defined as abstract in previous
-- packages. See those packages for descriptions of what these
-- methods do.
------------------------------------------------------------------------
function "=" (O1, O2 : in Object) return Boolean is
Curr1 : Node_Ref;
Curr2 : Node_Ref;
begin
Check_Object(O1);
Check_Object(O2);
if (O1.Count /= O2.Count) then
return False;
else
-- Compare all the elements in the lists to see if they are the
-- same.
Curr1 := O1.Head;
Curr2 := O2.Head;
while (Curr1 /= Null_Node) loop
if (Curr2 = Null_Node) then
raise Internal_List_Error;
end if;
if (O1.Data(Curr1).Val /= O2.Data(Curr2).Val) then
return False;
end if;
Curr1 := O1.Data(Curr1).Next;
Curr2 := O2.Data(Curr2).Next;
end loop;
if (Curr2 /= Null_Node) then
raise Internal_List_Error;
end if;
return True;
end if;
end "=";
------------------------------------------------------------------------
function Member_Count (O : in Object)
return Natural is
begin
Check_Object(O);
return O.Count;
end Member_Count;
------------------------------------------------------------------------
procedure Verify_Integrity (O : in Object) is
Curr : Node_Ref;
Count : Natural;
begin
Check_Object(O);
if (O.Count = 0) then
if ((O.Head /= Null_Node) or (O.Tail /= Null_Node)) then
raise Internal_List_Error;
end if;
else
Curr := O.Head;
if (O.Data(Curr).Prev /= Null_Node) then
raise Internal_List_Error;
end if;
-- Go through all the elemenets and make sure the prev and next
-- pointers point to each other for each node in the list.
Count := 1;
while (O.Data(Curr).Next /= Null_Node) loop
if (Count > O.Count) then
raise Internal_List_Error;
end if;
if (O.Data(O.Data(Curr).Next).Prev /= Curr) then
raise Internal_List_Error;
end if;
Curr := O.Data(Curr).Next;
Count := Count + 1;
end loop;
if (Count /= O.Count) then
raise Internal_List_Error;
end if;
if (Curr /= O.Tail) then
raise Internal_List_Error;
end if;
end if;
end Verify_Integrity;
------------------------------------------------------------------------
function Copy (O : in Object) return Asgc.Object_Class is
Retval : Object_Ptr;
begin
Retval := new Object(Size => O.Size);
Retval.all := O;
return Asgc.Object_Class(Retval);
end Copy;
------------------------------------------------------------------------
procedure Add_Before (Iter : in out Iterator; Val : in Contained_Type) is
begin
Check_Iterator_Empty_Ok(Iter);
Add_Before(Iter.Robj.all, Iter.Pos, Val);
if (Iter.Pos = Null_Node) then
Iter.Pos := Iter.Robj.Head;
else
Iter.Pos := Iter.Robj.Data(Iter.Pos).Prev;
end if;
Iter.Update := Iter.Robj.Update;
end Add_Before;
------------------------------------------------------------------------
procedure Add_After (Iter : in out Iterator; Val : in Contained_Type) is
begin
Check_Iterator_Empty_Ok(Iter);
Add_After(Iter.Robj.all, Iter.Pos, Val);
if (Iter.Pos = Null_Node) then
Iter.Pos := Iter.Robj.Tail;
else
Iter.Pos := Iter.Robj.Data(Iter.Pos).Next;
end if;
Iter.Offset := Iter.Offset + 1;
Iter.Update := Iter.Robj.Update;
end Add_After;
------------------------------------------------------------------------
procedure Delete (O : in out Object;
Val : in Contained_Type) is
Curr : Node_Ref;
Dummy_Is_End : End_Marker;
begin
Check_Object(O);
Curr := O.Head;
while ((Curr /= Null_Node) and then(O.Data(Curr).Val /= Val)) loop
Curr := O.Data(Curr).Next;
end loop;
if (Curr /= Null_Node) then
Delete(O, Curr, Dummy_Is_End);
else
raise Item_Not_Found;
end if;
end Delete;
------------------------------------------------------------------------
function Value_Exists (O : in Object;
Val : in Contained_Type)
return Boolean is
Curr : Node_Ref;
begin
Check_Object(O);
Curr := O.Head;
while ((Curr /= Null_Node) and then(O.Data(Curr).Val /= Val)) loop
Curr := O.Data(Curr).Next;
end loop;
return (Curr /= Null_Node);
end Value_Exists;
------------------------------------------------------------------------
procedure Add_At (O : in out Object;
Loc : in Positive;
Val : in Contained_Type) is
begin
Check_Object(O);
if (Loc > (O.Count + 1)) then
raise Constraint_Error;
end if;
if (Loc = 1) then
-- Special case for adding the first value.
Add_Before(O, O.Head, Val);
else
Add_After(O, Seek_To(O, Loc - 1), Val);
end if;
end Add_At;
------------------------------------------------------------------------
procedure Set_At (O : in out Object;
Loc : in Positive;
Val : in Contained_Type) is
Curr : Node_Ref;
Old_Val : Contained_Type;
begin
Check_Object(O);
if (Loc > O.Count) then
raise Constraint_Error;
end if;
Curr := Seek_To(O, Loc);
Old_Val := O.Data(Curr).Val;
O.Data(Curr).Val := Val;
-- Add then delete the values in case these are the same value. This
-- can avoid some nasty side effects.
if (O.Cb /= null) then
Added(O.Cb, O, O.Data(Curr).Val);
end if;
if (O.Cb /= null) then
Deleted(O.Cb, O, Old_Val);
end if;
end Set_At;
------------------------------------------------------------------------
function Get_At (O : in Object;
Loc : in Positive)
return Contained_Type is
Curr : Node_Ref;
begin
Check_Object(O);
if (Loc > O.Count) then
raise Constraint_Error;
end if;
Curr := Seek_To(O, Loc);
return O.Data(Curr).Val;
end Get_At;
------------------------------------------------------------------------
procedure Swap_At (O : in out Object;
Loc1, Loc2 : in Positive) is
Tmp : Contained_Type;
Pos1 : Node_Ref;
Pos2 : Node_Ref;
begin
Check_Object(O);
Pos1 := Seek_To(O, Loc1);
Pos2 := Seek_To(O, Loc2);
Tmp := O.Data(Pos1).Val;
O.Data(Pos1).Val := O.Data(Pos2).Val;
O.Data(Pos2).Val := Tmp;
end Swap_At;
------------------------------------------------------------------------
procedure Delete_At (O : in out Object;
Loc : in Positive) is
To_Delete : Node_Ref;
Is_End : End_Marker;
begin
Check_Object(O);
if (Loc > O.Count) then
raise Constraint_Error;
end if;
To_Delete := Seek_To(O, Loc);
Delete(O, To_Delete, Is_End);
end Delete_At;
------------------------------------------------------------------------
procedure Push (O : in out Object;
Val : in Contained_Type) is
begin
Add_At(O, 1, Val);
end Push;
------------------------------------------------------------------------
procedure Pop (O : in out Object;
Val : out Contained_Type) is
begin
Val := Get_At(O, 1);
Delete_At(O, 1);
end Pop;
------------------------------------------------------------------------
procedure Enqueue (O : in out Object; Val : in Contained_Type) is
begin
Check_Object(O);
Add_After(O, O.Tail, Val);
end Enqueue;
------------------------------------------------------------------------
procedure Dequeue (O : in out Object;
Val : out Contained_Type) is
begin
Val := Get_At(O, 1);
Delete_At(O, 1);
end Dequeue;
------------------------------------------------------------------------
function New_Iterator (O : access Object) return Asgc.Iterator_Class is
Retval : Iterator_Ptr;
begin
Check_Object(O.all);
Retval := new Iterator;
Retval.Robj := Object_Class(O);
return Asgc.Iterator_Class(Retval);
end New_Iterator;
------------------------------------------------------------------------
function New_Iterator (O : in Object_class) return Iterator is
Retval : Iterator;
begin
Retval.Robj := O;
return Retval;
end New_Iterator;
------------------------------------------------------------------------
procedure Free (Iter : access Iterator) is
To_Free : Iterator_Ptr := Iterator_Ptr(Iter);
begin
if (Iter.Is_Free) then
raise Iterator_Free;
end if;
Free_Iterator(To_Free);
end Free;
------------------------------------------------------------------------
procedure Set_Container (Iter : in out Iterator;
O : in Asgc.Object_Class) is
begin
Check_Object(Object'Class(O.all));
Iter.Robj := Object_Class(O);
Iter.Update := Invalid_Update;
end Set_Container;
------------------------------------------------------------------------
procedure Set (Iter : in Iterator; Val : in Contained_Type) is
Old_Val : Contained_Type;
begin
Check_Iterator(Iter);
Old_Val := Iter.Robj.Data(Iter.Pos).Val;
Iter.Robj.Data(Iter.Pos).Val := Val;
-- Add then delete the values in case these are the same value. This
-- can avoid some nasty side effects.
if (Iter.Robj.Cb /= null) then
Added(Iter.Robj.Cb, Iter.Robj.all, Iter.Robj.Data(Iter.Pos).Val);
end if;
if (Iter.Robj.Cb /= null) then
Deleted(Iter.Robj.Cb, Iter.Robj.all, Old_Val);
end if;
end Set;
------------------------------------------------------------------------
procedure First (Iter : in out Iterator; Is_End : out End_Marker) is
begin
Check_Iterator_No_Pos(Iter);
Iter.Pos := Iter.Robj.Head;
Iter.Update := Iter.Robj.Update;
if (Iter.Pos = Null_Node) then
Is_End := Past_End;
Iter.Offset := 0;
else
Is_End := Not_Past_End;
Iter.Offset := 1;
end if;
end First;
------------------------------------------------------------------------
procedure Next (Iter : in out Iterator; Is_End : out End_Marker) is
begin
Check_Iterator(Iter);
if (Iter.Robj.Data(Iter.Pos).Next = Null_Node) then
Is_End := Past_End;
else
Iter.Pos := Iter.Robj.Data(Iter.Pos).Next;
Is_End := Not_Past_End;
Iter.Offset := Iter.Offset + 1;
end if;
end Next;
------------------------------------------------------------------------
procedure Delete (Iter : in out Iterator; Is_End : out End_Marker) is
Local_Is_End : End_Marker;
Next_Node : Node_Ref;
begin
Check_Iterator(Iter);
Next_Node := Iter.Robj.Data(Iter.Pos).Next;
Delete(Iter.Robj.all, Iter.Pos, Local_Is_End);
if (Local_Is_End = Not_Past_End) then
Iter.Update := Iter.Robj.Update;
Iter.Pos := Next_Node;
end if;
Is_End := Local_Is_End;
end Delete;
------------------------------------------------------------------------
function Is_Same (Iter1, Iter2 : in Iterator) return Boolean is
begin
Check_Iterator(Iter1);
Check_Iterator(Iter2);
if (Iter1.Robj /= Iter2.Robj) then
raise Iterator_Mismatch;
end if;
return (Iter1.Pos = Iter2.Pos);
end Is_Same;
------------------------------------------------------------------------
function Get (Iter : in Iterator) return Contained_Type is
begin
Check_Iterator(Iter);
return Iter.Robj.Data(Iter.Pos).Val;
end Get;
------------------------------------------------------------------------
procedure Get_Incr (Iter : in out Iterator;
Val : out Contained_Type;
Is_End : out End_Marker) is
begin
Check_Iterator(Iter);
Val := Iter.Robj.Data(Iter.Pos).Val;
Next(Iter, Is_End);
end Get_Incr;
------------------------------------------------------------------------
procedure Get_Decr (Iter : in out Iterator;
Val : out Contained_Type;
Is_End : out End_Marker) is
begin
Check_Iterator(Iter);
Val := Iter.Robj.Data(Iter.Pos).Val;
Prev(Iter, Is_End);
end Get_Decr;
------------------------------------------------------------------------
procedure Last (Iter : in out Iterator; Is_End : out End_Marker) is
begin
Check_Iterator_No_Pos(Iter);
Iter.Pos := Iter.Robj.Tail;
Iter.Update := Iter.Robj.Update;
if (Iter.Pos = Null_Node) then
Is_End := Past_End;
Iter.Offset := 0;
else
Is_End := Not_Past_End;
Iter.Offset := Iter.Robj.Count;
end if;
end Last;
------------------------------------------------------------------------
procedure Prev (Iter : in out Iterator; Is_End : out End_Marker) is
begin
Check_Iterator(Iter);
if (Iter.Robj.Data(Iter.Pos).Prev = Null_Node) then
Is_End := Past_End;
else
Iter.Pos := Iter.Robj.Data(Iter.Pos).Prev;
Is_End := Not_Past_End;
Iter.Offset := Iter.Offset - 1;
end if;
end Prev;
------------------------------------------------------------------------
procedure Set_Loc (Iter : out Iterator; Loc : in Positive) is
begin
Check_Iterator_No_Pos(Iter);
if (Loc > Iter.Robj.Count) then
raise Constraint_Error;
end if;
if ((Iter.Update = Iter.Robj.Update)
and (Iter.Pos /= Null_Node))
then
-- We have a valid iterator, use it for checking the seek.
Iter.Pos := Seek_To(Iter.Robj.all, Loc, Iter.Pos, Iter.Offset);
else
Iter.Pos := Seek_To(Iter.Robj.all, Loc);
end if;
Iter.Offset := Loc;
Iter.Update := Iter.Robj.Update;
end Set_Loc;
------------------------------------------------------------------------
function Get_Loc (Iter : in Iterator)
return Natural is
begin
Check_Iterator_Empty_Ok(Iter);
return Iter.Offset;
end Get_Loc;
------------------------------------------------------------------------
function Is_After (Iter1, Iter2 : in Iterator) return Boolean is
begin
Check_Iterator_Empty_Ok(Iter1);
Check_Iterator_Empty_Ok(Iter2);
return (Iter1.Offset > Iter2.Offset);
end Is_After;
------------------------------------------------------------------------
function Is_Before (Iter1, Iter2 : in Iterator) return Boolean is
begin
Check_Iterator_Empty_Ok(Iter1);
Check_Iterator_Empty_Ok(Iter2);
return (Iter1.Offset < Iter2.Offset);
end Is_Before;
------------------------------------------------------------------------
function "-" (Iter1, Iter2 : in Iterator) return Integer is
begin
Check_Iterator_Empty_Ok(Iter1);
Check_Iterator_Empty_Ok(Iter2);
return (Integer(Iter1.Offset) - Integer(Iter2.Offset));
end "-";
------------------------------------------------------------------------
function "+" (Iter : in Iterator; Offset : in Integer)
return Iterator is
Retval : Iterator;
begin
Check_Iterator_Empty_Ok(Iter);
if ((Offset < 0)
and then (Iter.Offset <= -Offset))
then
raise Constraint_Error;
elsif ((Offset > 0)
and then ((Iter.Offset + Offset) > Iter.Robj.Count))
then
raise Constraint_Error;
end if;
Retval.Robj := Iter.Robj;
Retval.Offset := Iter.Offset + Offset;
if (Iter.Offset = 0) then
Retval.Pos := Seek_To(Iter.Robj.all, Retval.Offset);
else
Retval.Pos := Seek_To(Iter.Robj.all,
Retval.Offset,
Iter.Pos,
Iter.Offset);
end if;
Retval.Update := Iter.Robj.Update;
return Retval;
end "+";
------------------------------------------------------------------------
function "-" (Iter : in Iterator; Offset : in Integer)
return Iterator is
begin
return (Iter + (- Offset));
end "-";
------------------------------------------------------------------------
procedure Swap (Iter1, Iter2 : in out Iterator) is
Temp : Contained_Type;
begin
Check_Iterator(Iter1);
Check_Iterator(Iter2);
Temp := Iter1.Robj.Data(Iter1.Pos).Val;
Iter1.Robj.Data(Iter1.Pos).Val := Iter2.Robj.Data(Iter2.Pos).Val;
Iter2.Robj.Data(Iter2.Pos).Val := Temp;
end Swap;
------------------------------------------------------------------------
function "=" (Iter1, Iter2 : in Iterator) return Boolean is
begin
Check_Iterator(Iter1);
Check_Iterator(Iter2);
return (Iter1.Robj.Data(Iter1.Pos).Val = Iter2.Robj.Data(Iter2.Pos).Val);
end "=";
------------------------------------------------------------------------
function "=" (Iter : in Iterator; Val : in Contained_Type) return Boolean is
begin
Check_Iterator(Iter);
return (Iter.Robj.Data(Iter.Pos).Val = Val);
end "=";
------------------------------------------------------------------------
function "=" (Val : in Contained_Type; Iter : in Iterator) return Boolean is
begin
Check_Iterator(Iter);
return (Val = Iter.Robj.Data(Iter.Pos).Val);
end "=";
end Asgc.Ordered.Dlist.Fixed;