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Diffstat (limited to 'gcc-4.7/gcc/ada/a-cimutr.adb')
| -rw-r--r-- | gcc-4.7/gcc/ada/a-cimutr.adb | 2786 |
1 files changed, 0 insertions, 2786 deletions
diff --git a/gcc-4.7/gcc/ada/a-cimutr.adb b/gcc-4.7/gcc/ada/a-cimutr.adb deleted file mode 100644 index 050c0395d..000000000 --- a/gcc-4.7/gcc/ada/a-cimutr.adb +++ /dev/null @@ -1,2786 +0,0 @@ ------------------------------------------------------------------------------- --- -- --- GNAT LIBRARY COMPONENTS -- --- -- --- ADA.CONTAINERS.INDEFINITE_MULTIWAY_TREES -- --- -- --- B o d y -- --- -- --- Copyright (C) 2004-2012, Free Software Foundation, Inc. -- --- -- --- GNAT is free software; you can redistribute it and/or modify it under -- --- terms of the GNU General Public License as published by the Free Soft- -- --- ware Foundation; either version 3, or (at your option) any later ver- -- --- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- --- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- --- or FITNESS FOR A PARTICULAR PURPOSE. -- --- -- --- As a special exception under Section 7 of GPL version 3, you are granted -- --- additional permissions described in the GCC Runtime Library Exception, -- --- version 3.1, as published by the Free Software Foundation. -- --- -- --- You should have received a copy of the GNU General Public License and -- --- a copy of the GCC Runtime Library Exception along with this program; -- --- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- --- <http://www.gnu.org/licenses/>. -- --- -- --- This unit was originally developed by Matthew J Heaney. -- ------------------------------------------------------------------------------- - -with Ada.Unchecked_Deallocation; - -with System; use type System.Address; - -package body Ada.Containers.Indefinite_Multiway_Trees is - - -------------------- - -- Root_Iterator -- - -------------------- - - type Root_Iterator is abstract new Limited_Controlled and - Tree_Iterator_Interfaces.Forward_Iterator with - record - Container : Tree_Access; - Subtree : Tree_Node_Access; - end record; - - overriding procedure Finalize (Object : in out Root_Iterator); - - ----------------------- - -- Subtree_Iterator -- - ----------------------- - - type Subtree_Iterator is new Root_Iterator with null record; - - overriding function First (Object : Subtree_Iterator) return Cursor; - - overriding function Next - (Object : Subtree_Iterator; - Position : Cursor) return Cursor; - - --------------------- - -- Child_Iterator -- - --------------------- - - type Child_Iterator is new Root_Iterator and - Tree_Iterator_Interfaces.Reversible_Iterator with null record; - - overriding function First (Object : Child_Iterator) return Cursor; - - overriding function Next - (Object : Child_Iterator; - Position : Cursor) return Cursor; - - overriding function Last (Object : Child_Iterator) return Cursor; - - overriding function Previous - (Object : Child_Iterator; - Position : Cursor) return Cursor; - - ----------------------- - -- Local Subprograms -- - ----------------------- - - function Root_Node (Container : Tree) return Tree_Node_Access; - - procedure Free_Element is - new Ada.Unchecked_Deallocation (Element_Type, Element_Access); - - procedure Deallocate_Node (X : in out Tree_Node_Access); - - procedure Deallocate_Children - (Subtree : Tree_Node_Access; - Count : in out Count_Type); - - procedure Deallocate_Subtree - (Subtree : in out Tree_Node_Access; - Count : in out Count_Type); - - function Equal_Children - (Left_Subtree, Right_Subtree : Tree_Node_Access) return Boolean; - - function Equal_Subtree - (Left_Subtree, Right_Subtree : Tree_Node_Access) return Boolean; - - procedure Iterate_Children - (Container : Tree_Access; - Subtree : Tree_Node_Access; - Process : not null access procedure (Position : Cursor)); - - procedure Iterate_Subtree - (Container : Tree_Access; - Subtree : Tree_Node_Access; - Process : not null access procedure (Position : Cursor)); - - procedure Copy_Children - (Source : Children_Type; - Parent : Tree_Node_Access; - Count : in out Count_Type); - - procedure Copy_Subtree - (Source : Tree_Node_Access; - Parent : Tree_Node_Access; - Target : out Tree_Node_Access; - Count : in out Count_Type); - - function Find_In_Children - (Subtree : Tree_Node_Access; - Item : Element_Type) return Tree_Node_Access; - - function Find_In_Subtree - (Subtree : Tree_Node_Access; - Item : Element_Type) return Tree_Node_Access; - - function Child_Count (Children : Children_Type) return Count_Type; - - function Subtree_Node_Count - (Subtree : Tree_Node_Access) return Count_Type; - - function Is_Reachable (From, To : Tree_Node_Access) return Boolean; - - procedure Remove_Subtree (Subtree : Tree_Node_Access); - - procedure Insert_Subtree_Node - (Subtree : Tree_Node_Access; - Parent : Tree_Node_Access; - Before : Tree_Node_Access); - - procedure Insert_Subtree_List - (First : Tree_Node_Access; - Last : Tree_Node_Access; - Parent : Tree_Node_Access; - Before : Tree_Node_Access); - - procedure Splice_Children - (Target_Parent : Tree_Node_Access; - Before : Tree_Node_Access; - Source_Parent : Tree_Node_Access); - - --------- - -- "=" -- - --------- - - function "=" (Left, Right : Tree) return Boolean is - begin - if Left'Address = Right'Address then - return True; - end if; - - return Equal_Children (Root_Node (Left), Root_Node (Right)); - end "="; - - ------------ - -- Adjust -- - ------------ - - procedure Adjust (Container : in out Tree) is - Source : constant Children_Type := Container.Root.Children; - Source_Count : constant Count_Type := Container.Count; - Target_Count : Count_Type; - - begin - -- We first restore the target container to its default-initialized - -- state, before we attempt any allocation, to ensure that invariants - -- are preserved in the event that the allocation fails. - - Container.Root.Children := Children_Type'(others => null); - Container.Busy := 0; - Container.Lock := 0; - Container.Count := 0; - - -- Copy_Children returns a count of the number of nodes that it - -- allocates, but it works by incrementing the value that is passed in. - -- We must therefore initialize the count value before calling - -- Copy_Children. - - Target_Count := 0; - - -- Now we attempt the allocation of subtrees. The invariants are - -- satisfied even if the allocation fails. - - Copy_Children (Source, Root_Node (Container), Target_Count); - pragma Assert (Target_Count = Source_Count); - - Container.Count := Source_Count; - end Adjust; - - procedure Adjust (Control : in out Reference_Control_Type) is - begin - if Control.Container /= null then - declare - C : Tree renames Control.Container.all; - B : Natural renames C.Busy; - L : Natural renames C.Lock; - begin - B := B + 1; - L := L + 1; - end; - end if; - end Adjust; - - ------------------- - -- Ancestor_Find -- - ------------------- - - function Ancestor_Find - (Position : Cursor; - Item : Element_Type) return Cursor - is - R, N : Tree_Node_Access; - - begin - if Position = No_Element then - raise Constraint_Error with "Position cursor has no element"; - end if; - - -- Commented-out pending ARG ruling. ??? - - -- if Position.Container /= Container'Unrestricted_Access then - -- raise Program_Error with "Position cursor not in container"; - -- end if; - - -- AI-0136 says to raise PE if Position equals the root node. This does - -- not seem correct, as this value is just the limiting condition of the - -- search. For now we omit this check pending a ruling from the ARG.??? - - -- if Is_Root (Position) then - -- raise Program_Error with "Position cursor designates root"; - -- end if; - - R := Root_Node (Position.Container.all); - N := Position.Node; - while N /= R loop - if N.Element.all = Item then - return Cursor'(Position.Container, N); - end if; - - N := N.Parent; - end loop; - - return No_Element; - end Ancestor_Find; - - ------------------ - -- Append_Child -- - ------------------ - - procedure Append_Child - (Container : in out Tree; - Parent : Cursor; - New_Item : Element_Type; - Count : Count_Type := 1) - is - First, Last : Tree_Node_Access; - Element : Element_Access; - - begin - if Parent = No_Element then - raise Constraint_Error with "Parent cursor has no element"; - end if; - - if Parent.Container /= Container'Unrestricted_Access then - raise Program_Error with "Parent cursor not in container"; - end if; - - if Count = 0 then - return; - end if; - - if Container.Busy > 0 then - raise Program_Error - with "attempt to tamper with cursors (tree is busy)"; - end if; - - Element := new Element_Type'(New_Item); - First := new Tree_Node_Type'(Parent => Parent.Node, - Element => Element, - others => <>); - - Last := First; - - for J in Count_Type'(2) .. Count loop - - -- Reclaim other nodes if Storage_Error. ??? - - Element := new Element_Type'(New_Item); - Last.Next := new Tree_Node_Type'(Parent => Parent.Node, - Prev => Last, - Element => Element, - others => <>); - - Last := Last.Next; - end loop; - - Insert_Subtree_List - (First => First, - Last => Last, - Parent => Parent.Node, - Before => null); -- null means "insert at end of list" - - -- In order for operation Node_Count to complete in O(1) time, we cache - -- the count value. Here we increment the total count by the number of - -- nodes we just inserted. - - Container.Count := Container.Count + Count; - end Append_Child; - - ------------ - -- Assign -- - ------------ - - procedure Assign (Target : in out Tree; Source : Tree) is - Source_Count : constant Count_Type := Source.Count; - Target_Count : Count_Type; - - begin - if Target'Address = Source'Address then - return; - end if; - - Target.Clear; -- checks busy bit - - -- Copy_Children returns the number of nodes that it allocates, but it - -- does this by incrementing the count value passed in, so we must - -- initialize the count before calling Copy_Children. - - Target_Count := 0; - - -- Note that Copy_Children inserts the newly-allocated children into - -- their parent list only after the allocation of all the children has - -- succeeded. This preserves invariants even if the allocation fails. - - Copy_Children (Source.Root.Children, Root_Node (Target), Target_Count); - pragma Assert (Target_Count = Source_Count); - - Target.Count := Source_Count; - end Assign; - - ----------------- - -- Child_Count -- - ----------------- - - function Child_Count (Parent : Cursor) return Count_Type is - begin - if Parent = No_Element then - return 0; - else - return Child_Count (Parent.Node.Children); - end if; - end Child_Count; - - function Child_Count (Children : Children_Type) return Count_Type is - Result : Count_Type; - Node : Tree_Node_Access; - - begin - Result := 0; - Node := Children.First; - while Node /= null loop - Result := Result + 1; - Node := Node.Next; - end loop; - - return Result; - end Child_Count; - - ----------------- - -- Child_Depth -- - ----------------- - - function Child_Depth (Parent, Child : Cursor) return Count_Type is - Result : Count_Type; - N : Tree_Node_Access; - - begin - if Parent = No_Element then - raise Constraint_Error with "Parent cursor has no element"; - end if; - - if Child = No_Element then - raise Constraint_Error with "Child cursor has no element"; - end if; - - if Parent.Container /= Child.Container then - raise Program_Error with "Parent and Child in different containers"; - end if; - - Result := 0; - N := Child.Node; - while N /= Parent.Node loop - Result := Result + 1; - N := N.Parent; - - if N = null then - raise Program_Error with "Parent is not ancestor of Child"; - end if; - end loop; - - return Result; - end Child_Depth; - - ----------- - -- Clear -- - ----------- - - procedure Clear (Container : in out Tree) is - Container_Count : Count_Type; - Children_Count : Count_Type; - - begin - if Container.Busy > 0 then - raise Program_Error - with "attempt to tamper with cursors (tree is busy)"; - end if; - - -- We first set the container count to 0, in order to preserve - -- invariants in case the deallocation fails. (This works because - -- Deallocate_Children immediately removes the children from their - -- parent, and then does the actual deallocation.) - - Container_Count := Container.Count; - Container.Count := 0; - - -- Deallocate_Children returns the number of nodes that it deallocates, - -- but it does this by incrementing the count value that is passed in, - -- so we must first initialize the count return value before calling it. - - Children_Count := 0; - - -- See comment above. Deallocate_Children immediately removes the - -- children list from their parent node (here, the root of the tree), - -- and only after that does it attempt the actual deallocation. So even - -- if the deallocation fails, the representation invariants - - Deallocate_Children (Root_Node (Container), Children_Count); - pragma Assert (Children_Count = Container_Count); - end Clear; - - ------------------------ - -- Constant_Reference -- - ------------------------ - - function Constant_Reference - (Container : aliased Tree; - Position : Cursor) return Constant_Reference_Type - is - begin - if Position.Container = null then - raise Constraint_Error with - "Position cursor has no element"; - end if; - - if Position.Container /= Container'Unrestricted_Access then - raise Program_Error with - "Position cursor designates wrong container"; - end if; - - if Position.Node = Root_Node (Container) then - raise Program_Error with "Position cursor designates root"; - end if; - - if Position.Node.Element = null then - raise Program_Error with "Node has no element"; - end if; - - -- Implement Vet for multiway tree??? - -- pragma Assert (Vet (Position), - -- "Position cursor in Constant_Reference is bad"); - - declare - C : Tree renames Position.Container.all; - B : Natural renames C.Busy; - L : Natural renames C.Lock; - begin - return R : constant Constant_Reference_Type := - (Element => Position.Node.Element.all'Access, - Control => - (Controlled with Container'Unrestricted_Access)) - do - B := B + 1; - L := L + 1; - end return; - end; - end Constant_Reference; - - -------------- - -- Contains -- - -------------- - - function Contains - (Container : Tree; - Item : Element_Type) return Boolean - is - begin - return Find (Container, Item) /= No_Element; - end Contains; - - ---------- - -- Copy -- - ---------- - - function Copy (Source : Tree) return Tree is - begin - return Target : Tree do - Copy_Children - (Source => Source.Root.Children, - Parent => Root_Node (Target), - Count => Target.Count); - - pragma Assert (Target.Count = Source.Count); - end return; - end Copy; - - ------------------- - -- Copy_Children -- - ------------------- - - procedure Copy_Children - (Source : Children_Type; - Parent : Tree_Node_Access; - Count : in out Count_Type) - is - pragma Assert (Parent /= null); - pragma Assert (Parent.Children.First = null); - pragma Assert (Parent.Children.Last = null); - - CC : Children_Type; - C : Tree_Node_Access; - - begin - -- We special-case the first allocation, in order to establish the - -- representation invariants for type Children_Type. - - C := Source.First; - - if C = null then - return; - end if; - - Copy_Subtree - (Source => C, - Parent => Parent, - Target => CC.First, - Count => Count); - - CC.Last := CC.First; - - -- The representation invariants for the Children_Type list have been - -- established, so we can now copy the remaining children of Source. - - C := C.Next; - while C /= null loop - Copy_Subtree - (Source => C, - Parent => Parent, - Target => CC.Last.Next, - Count => Count); - - CC.Last.Next.Prev := CC.Last; - CC.Last := CC.Last.Next; - - C := C.Next; - end loop; - - -- We add the newly-allocated children to their parent list only after - -- the allocation has succeeded, in order to preserve invariants of the - -- parent. - - Parent.Children := CC; - end Copy_Children; - - ------------------ - -- Copy_Subtree -- - ------------------ - - procedure Copy_Subtree - (Target : in out Tree; - Parent : Cursor; - Before : Cursor; - Source : Cursor) - is - Target_Subtree : Tree_Node_Access; - Target_Count : Count_Type; - - begin - if Parent = No_Element then - raise Constraint_Error with "Parent cursor has no element"; - end if; - - if Parent.Container /= Target'Unrestricted_Access then - raise Program_Error with "Parent cursor not in container"; - end if; - - if Before /= No_Element then - if Before.Container /= Target'Unrestricted_Access then - raise Program_Error with "Before cursor not in container"; - end if; - - if Before.Node.Parent /= Parent.Node then - raise Constraint_Error with "Before cursor not child of Parent"; - end if; - end if; - - if Source = No_Element then - return; - end if; - - if Is_Root (Source) then - raise Constraint_Error with "Source cursor designates root"; - end if; - - -- Copy_Subtree returns a count of the number of nodes that it - -- allocates, but it works by incrementing the value that is passed in. - -- We must therefore initialize the count value before calling - -- Copy_Subtree. - - Target_Count := 0; - - Copy_Subtree - (Source => Source.Node, - Parent => Parent.Node, - Target => Target_Subtree, - Count => Target_Count); - - pragma Assert (Target_Subtree /= null); - pragma Assert (Target_Subtree.Parent = Parent.Node); - pragma Assert (Target_Count >= 1); - - Insert_Subtree_Node - (Subtree => Target_Subtree, - Parent => Parent.Node, - Before => Before.Node); - - -- In order for operation Node_Count to complete in O(1) time, we cache - -- the count value. Here we increment the total count by the number of - -- nodes we just inserted. - - Target.Count := Target.Count + Target_Count; - end Copy_Subtree; - - procedure Copy_Subtree - (Source : Tree_Node_Access; - Parent : Tree_Node_Access; - Target : out Tree_Node_Access; - Count : in out Count_Type) - is - E : constant Element_Access := new Element_Type'(Source.Element.all); - - begin - Target := new Tree_Node_Type'(Element => E, - Parent => Parent, - others => <>); - - Count := Count + 1; - - Copy_Children - (Source => Source.Children, - Parent => Target, - Count => Count); - end Copy_Subtree; - - ------------------------- - -- Deallocate_Children -- - ------------------------- - - procedure Deallocate_Children - (Subtree : Tree_Node_Access; - Count : in out Count_Type) - is - pragma Assert (Subtree /= null); - - CC : Children_Type := Subtree.Children; - C : Tree_Node_Access; - - begin - -- We immediately remove the children from their parent, in order to - -- preserve invariants in case the deallocation fails. - - Subtree.Children := Children_Type'(others => null); - - while CC.First /= null loop - C := CC.First; - CC.First := C.Next; - - Deallocate_Subtree (C, Count); - end loop; - end Deallocate_Children; - - --------------------- - -- Deallocate_Node -- - --------------------- - - procedure Deallocate_Node (X : in out Tree_Node_Access) is - procedure Free_Node is - new Ada.Unchecked_Deallocation (Tree_Node_Type, Tree_Node_Access); - - -- Start of processing for Deallocate_Node - - begin - if X /= null then - Free_Element (X.Element); - Free_Node (X); - end if; - end Deallocate_Node; - - ------------------------ - -- Deallocate_Subtree -- - ------------------------ - - procedure Deallocate_Subtree - (Subtree : in out Tree_Node_Access; - Count : in out Count_Type) - is - begin - Deallocate_Children (Subtree, Count); - Deallocate_Node (Subtree); - Count := Count + 1; - end Deallocate_Subtree; - - --------------------- - -- Delete_Children -- - --------------------- - - procedure Delete_Children - (Container : in out Tree; - Parent : Cursor) - is - Count : Count_Type; - - begin - if Parent = No_Element then - raise Constraint_Error with "Parent cursor has no element"; - end if; - - if Parent.Container /= Container'Unrestricted_Access then - raise Program_Error with "Parent cursor not in container"; - end if; - - if Container.Busy > 0 then - raise Program_Error - with "attempt to tamper with cursors (tree is busy)"; - end if; - - -- Deallocate_Children returns a count of the number of nodes - -- that it deallocates, but it works by incrementing the - -- value that is passed in. We must therefore initialize - -- the count value before calling Deallocate_Children. - - Count := 0; - - Deallocate_Children (Parent.Node, Count); - pragma Assert (Count <= Container.Count); - - Container.Count := Container.Count - Count; - end Delete_Children; - - ----------------- - -- Delete_Leaf -- - ----------------- - - procedure Delete_Leaf - (Container : in out Tree; - Position : in out Cursor) - is - X : Tree_Node_Access; - - begin - if Position = No_Element then - raise Constraint_Error with "Position cursor has no element"; - end if; - - if Position.Container /= Container'Unrestricted_Access then - raise Program_Error with "Position cursor not in container"; - end if; - - if Is_Root (Position) then - raise Program_Error with "Position cursor designates root"; - end if; - - if not Is_Leaf (Position) then - raise Constraint_Error with "Position cursor does not designate leaf"; - end if; - - if Container.Busy > 0 then - raise Program_Error - with "attempt to tamper with cursors (tree is busy)"; - end if; - - X := Position.Node; - Position := No_Element; - - -- Restore represention invariants before attempting the actual - -- deallocation. - - Remove_Subtree (X); - Container.Count := Container.Count - 1; - - -- It is now safe to attempt the deallocation. This leaf node has been - -- disassociated from the tree, so even if the deallocation fails, - -- representation invariants will remain satisfied. - - Deallocate_Node (X); - end Delete_Leaf; - - -------------------- - -- Delete_Subtree -- - -------------------- - - procedure Delete_Subtree - (Container : in out Tree; - Position : in out Cursor) - is - X : Tree_Node_Access; - Count : Count_Type; - - begin - if Position = No_Element then - raise Constraint_Error with "Position cursor has no element"; - end if; - - if Position.Container /= Container'Unrestricted_Access then - raise Program_Error with "Position cursor not in container"; - end if; - - if Is_Root (Position) then - raise Program_Error with "Position cursor designates root"; - end if; - - if Container.Busy > 0 then - raise Program_Error - with "attempt to tamper with cursors (tree is busy)"; - end if; - - X := Position.Node; - Position := No_Element; - - -- Here is one case where a deallocation failure can result in the - -- violation of a representation invariant. We disassociate the subtree - -- from the tree now, but we only decrement the total node count after - -- we attempt the deallocation. However, if the deallocation fails, the - -- total node count will not get decremented. - - -- One way around this dilemma is to count the nodes in the subtree - -- before attempt to delete the subtree, but that is an O(n) operation, - -- so it does not seem worth it. - - -- Perhaps this is much ado about nothing, since the only way - -- deallocation can fail is if Controlled Finalization fails: this - -- propagates Program_Error so all bets are off anyway. ??? - - Remove_Subtree (X); - - -- Deallocate_Subtree returns a count of the number of nodes that it - -- deallocates, but it works by incrementing the value that is passed - -- in. We must therefore initialize the count value before calling - -- Deallocate_Subtree. - - Count := 0; - - Deallocate_Subtree (X, Count); - pragma Assert (Count <= Container.Count); - - -- See comments above. We would prefer to do this sooner, but there's no - -- way to satisfy that goal without an potentially severe execution - -- penalty. - - Container.Count := Container.Count - Count; - end Delete_Subtree; - - ----------- - -- Depth -- - ----------- - - function Depth (Position : Cursor) return Count_Type is - Result : Count_Type; - N : Tree_Node_Access; - - begin - Result := 0; - N := Position.Node; - while N /= null loop - N := N.Parent; - Result := Result + 1; - end loop; - - return Result; - end Depth; - - ------------- - -- Element -- - ------------- - - function Element (Position : Cursor) return Element_Type is - begin - if Position.Container = null then - raise Constraint_Error with "Position cursor has no element"; - end if; - - if Position.Node = Root_Node (Position.Container.all) then - raise Program_Error with "Position cursor designates root"; - end if; - - return Position.Node.Element.all; - end Element; - - -------------------- - -- Equal_Children -- - -------------------- - - function Equal_Children - (Left_Subtree : Tree_Node_Access; - Right_Subtree : Tree_Node_Access) return Boolean - is - Left_Children : Children_Type renames Left_Subtree.Children; - Right_Children : Children_Type renames Right_Subtree.Children; - - L, R : Tree_Node_Access; - - begin - if Child_Count (Left_Children) /= Child_Count (Right_Children) then - return False; - end if; - - L := Left_Children.First; - R := Right_Children.First; - while L /= null loop - if not Equal_Subtree (L, R) then - return False; - end if; - - L := L.Next; - R := R.Next; - end loop; - - return True; - end Equal_Children; - - ------------------- - -- Equal_Subtree -- - ------------------- - - function Equal_Subtree - (Left_Position : Cursor; - Right_Position : Cursor) return Boolean - is - begin - if Left_Position = No_Element then - raise Constraint_Error with "Left cursor has no element"; - end if; - - if Right_Position = No_Element then - raise Constraint_Error with "Right cursor has no element"; - end if; - - if Left_Position = Right_Position then - return True; - end if; - - if Is_Root (Left_Position) then - if not Is_Root (Right_Position) then - return False; - end if; - - return Equal_Children (Left_Position.Node, Right_Position.Node); - end if; - - if Is_Root (Right_Position) then - return False; - end if; - - return Equal_Subtree (Left_Position.Node, Right_Position.Node); - end Equal_Subtree; - - function Equal_Subtree - (Left_Subtree : Tree_Node_Access; - Right_Subtree : Tree_Node_Access) return Boolean - is - begin - if Left_Subtree.Element.all /= Right_Subtree.Element.all then - return False; - end if; - - return Equal_Children (Left_Subtree, Right_Subtree); - end Equal_Subtree; - - -------------- - -- Finalize -- - -------------- - - procedure Finalize (Object : in out Root_Iterator) is - B : Natural renames Object.Container.Busy; - begin - B := B - 1; - end Finalize; - - procedure Finalize (Control : in out Reference_Control_Type) is - begin - if Control.Container /= null then - declare - C : Tree renames Control.Container.all; - B : Natural renames C.Busy; - L : Natural renames C.Lock; - begin - B := B - 1; - L := L - 1; - end; - - Control.Container := null; - end if; - end Finalize; - - ---------- - -- Find -- - ---------- - - function Find - (Container : Tree; - Item : Element_Type) return Cursor - is - N : constant Tree_Node_Access := - Find_In_Children (Root_Node (Container), Item); - - begin - if N = null then - return No_Element; - end if; - - return Cursor'(Container'Unrestricted_Access, N); - end Find; - - ----------- - -- First -- - ----------- - - overriding function First (Object : Subtree_Iterator) return Cursor is - begin - if Object.Subtree = Root_Node (Object.Container.all) then - return First_Child (Root (Object.Container.all)); - else - return Cursor'(Object.Container, Object.Subtree); - end if; - end First; - - overriding function First (Object : Child_Iterator) return Cursor is - begin - return First_Child (Cursor'(Object.Container, Object.Subtree)); - end First; - - ----------------- - -- First_Child -- - ----------------- - - function First_Child (Parent : Cursor) return Cursor is - Node : Tree_Node_Access; - - begin - if Parent = No_Element then - raise Constraint_Error with "Parent cursor has no element"; - end if; - - Node := Parent.Node.Children.First; - - if Node = null then - return No_Element; - end if; - - return Cursor'(Parent.Container, Node); - end First_Child; - - ------------------------- - -- First_Child_Element -- - ------------------------- - - function First_Child_Element (Parent : Cursor) return Element_Type is - begin - return Element (First_Child (Parent)); - end First_Child_Element; - - ---------------------- - -- Find_In_Children -- - ---------------------- - - function Find_In_Children - (Subtree : Tree_Node_Access; - Item : Element_Type) return Tree_Node_Access - is - N, Result : Tree_Node_Access; - - begin - N := Subtree.Children.First; - while N /= null loop - Result := Find_In_Subtree (N, Item); - - if Result /= null then - return Result; - end if; - - N := N.Next; - end loop; - - return null; - end Find_In_Children; - - --------------------- - -- Find_In_Subtree -- - --------------------- - - function Find_In_Subtree - (Position : Cursor; - Item : Element_Type) return Cursor - is - Result : Tree_Node_Access; - - begin - if Position = No_Element then - raise Constraint_Error with "Position cursor has no element"; - end if; - - -- Commented-out pending ruling from ARG. ??? - - -- if Position.Container /= Container'Unrestricted_Access then - -- raise Program_Error with "Position cursor not in container"; - -- end if; - - if Is_Root (Position) then - Result := Find_In_Children (Position.Node, Item); - - else - Result := Find_In_Subtree (Position.Node, Item); - end if; - - if Result = null then - return No_Element; - end if; - - return Cursor'(Position.Container, Result); - end Find_In_Subtree; - - function Find_In_Subtree - (Subtree : Tree_Node_Access; - Item : Element_Type) return Tree_Node_Access - is - begin - if Subtree.Element.all = Item then - return Subtree; - end if; - - return Find_In_Children (Subtree, Item); - end Find_In_Subtree; - - ----------------- - -- Has_Element -- - ----------------- - - function Has_Element (Position : Cursor) return Boolean is - begin - if Position = No_Element then - return False; - end if; - - return Position.Node.Parent /= null; - end Has_Element; - - ------------------ - -- Insert_Child -- - ------------------ - - procedure Insert_Child - (Container : in out Tree; - Parent : Cursor; - Before : Cursor; - New_Item : Element_Type; - Count : Count_Type := 1) - is - Position : Cursor; - pragma Unreferenced (Position); - - begin - Insert_Child (Container, Parent, Before, New_Item, Position, Count); - end Insert_Child; - - procedure Insert_Child - (Container : in out Tree; - Parent : Cursor; - Before : Cursor; - New_Item : Element_Type; - Position : out Cursor; - Count : Count_Type := 1) - is - Last : Tree_Node_Access; - Element : Element_Access; - - begin - if Parent = No_Element then - raise Constraint_Error with "Parent cursor has no element"; - end if; - - if Parent.Container /= Container'Unrestricted_Access then - raise Program_Error with "Parent cursor not in container"; - end if; - - if Before /= No_Element then - if Before.Container /= Container'Unrestricted_Access then - raise Program_Error with "Before cursor not in container"; - end if; - - if Before.Node.Parent /= Parent.Node then - raise Constraint_Error with "Parent cursor not parent of Before"; - end if; - end if; - - if Count = 0 then - Position := No_Element; -- Need ruling from ARG ??? - return; - end if; - - if Container.Busy > 0 then - raise Program_Error - with "attempt to tamper with cursors (tree is busy)"; - end if; - - Position.Container := Parent.Container; - - Element := new Element_Type'(New_Item); - Position.Node := new Tree_Node_Type'(Parent => Parent.Node, - Element => Element, - others => <>); - - Last := Position.Node; - - for J in Count_Type'(2) .. Count loop - -- Reclaim other nodes if Storage_Error. ??? - - Element := new Element_Type'(New_Item); - Last.Next := new Tree_Node_Type'(Parent => Parent.Node, - Prev => Last, - Element => Element, - others => <>); - - Last := Last.Next; - end loop; - - Insert_Subtree_List - (First => Position.Node, - Last => Last, - Parent => Parent.Node, - Before => Before.Node); - - -- In order for operation Node_Count to complete in O(1) time, we cache - -- the count value. Here we increment the total count by the number of - -- nodes we just inserted. - - Container.Count := Container.Count + Count; - end Insert_Child; - - ------------------------- - -- Insert_Subtree_List -- - ------------------------- - - procedure Insert_Subtree_List - (First : Tree_Node_Access; - Last : Tree_Node_Access; - Parent : Tree_Node_Access; - Before : Tree_Node_Access) - is - pragma Assert (Parent /= null); - C : Children_Type renames Parent.Children; - - begin - -- This is a simple utility operation to insert a list of nodes (from - -- First..Last) as children of Parent. The Before node specifies where - -- the new children should be inserted relative to the existing - -- children. - - if First = null then - pragma Assert (Last = null); - return; - end if; - - pragma Assert (Last /= null); - pragma Assert (Before = null or else Before.Parent = Parent); - - if C.First = null then - C.First := First; - C.First.Prev := null; - C.Last := Last; - C.Last.Next := null; - - elsif Before = null then -- means "insert after existing nodes" - C.Last.Next := First; - First.Prev := C.Last; - C.Last := Last; - C.Last.Next := null; - - elsif Before = C.First then - Last.Next := C.First; - C.First.Prev := Last; - C.First := First; - C.First.Prev := null; - - else - Before.Prev.Next := First; - First.Prev := Before.Prev; - Last.Next := Before; - Before.Prev := Last; - end if; - end Insert_Subtree_List; - - ------------------------- - -- Insert_Subtree_Node -- - ------------------------- - - procedure Insert_Subtree_Node - (Subtree : Tree_Node_Access; - Parent : Tree_Node_Access; - Before : Tree_Node_Access) - is - begin - -- This is a simple wrapper operation to insert a single child into the - -- Parent's children list. - - Insert_Subtree_List - (First => Subtree, - Last => Subtree, - Parent => Parent, - Before => Before); - end Insert_Subtree_Node; - - -------------- - -- Is_Empty -- - -------------- - - function Is_Empty (Container : Tree) return Boolean is - begin - return Container.Root.Children.First = null; - end Is_Empty; - - ------------- - -- Is_Leaf -- - ------------- - - function Is_Leaf (Position : Cursor) return Boolean is - begin - if Position = No_Element then - return False; - end if; - - return Position.Node.Children.First = null; - end Is_Leaf; - - ------------------ - -- Is_Reachable -- - ------------------ - - function Is_Reachable (From, To : Tree_Node_Access) return Boolean is - pragma Assert (From /= null); - pragma Assert (To /= null); - - N : Tree_Node_Access; - - begin - N := From; - while N /= null loop - if N = To then - return True; - end if; - - N := N.Parent; - end loop; - - return False; - end Is_Reachable; - - ------------- - -- Is_Root -- - ------------- - - function Is_Root (Position : Cursor) return Boolean is - begin - if Position.Container = null then - return False; - end if; - - return Position = Root (Position.Container.all); - end Is_Root; - - ------------- - -- Iterate -- - ------------- - - procedure Iterate - (Container : Tree; - Process : not null access procedure (Position : Cursor)) - is - B : Natural renames Container'Unrestricted_Access.all.Busy; - - begin - B := B + 1; - - Iterate_Children - (Container => Container'Unrestricted_Access, - Subtree => Root_Node (Container), - Process => Process); - - B := B - 1; - - exception - when others => - B := B - 1; - raise; - end Iterate; - - function Iterate (Container : Tree) - return Tree_Iterator_Interfaces.Forward_Iterator'Class - is - begin - return Iterate_Subtree (Root (Container)); - end Iterate; - - ---------------------- - -- Iterate_Children -- - ---------------------- - - procedure Iterate_Children - (Parent : Cursor; - Process : not null access procedure (Position : Cursor)) - is - begin - if Parent = No_Element then - raise Constraint_Error with "Parent cursor has no element"; - end if; - - declare - B : Natural renames Parent.Container.Busy; - C : Tree_Node_Access; - - begin - B := B + 1; - - C := Parent.Node.Children.First; - while C /= null loop - Process (Position => Cursor'(Parent.Container, Node => C)); - C := C.Next; - end loop; - - B := B - 1; - - exception - when others => - B := B - 1; - raise; - end; - end Iterate_Children; - - procedure Iterate_Children - (Container : Tree_Access; - Subtree : Tree_Node_Access; - Process : not null access procedure (Position : Cursor)) - is - Node : Tree_Node_Access; - - begin - -- This is a helper function to recursively iterate over all the nodes - -- in a subtree, in depth-first fashion. This particular helper just - -- visits the children of this subtree, not the root of the subtree node - -- itself. This is useful when starting from the ultimate root of the - -- entire tree (see Iterate), as that root does not have an element. - - Node := Subtree.Children.First; - while Node /= null loop - Iterate_Subtree (Container, Node, Process); - Node := Node.Next; - end loop; - end Iterate_Children; - - function Iterate_Children - (Container : Tree; - Parent : Cursor) - return Tree_Iterator_Interfaces.Reversible_Iterator'Class - is - C : constant Tree_Access := Container'Unrestricted_Access; - B : Natural renames C.Busy; - - begin - if Parent = No_Element then - raise Constraint_Error with "Parent cursor has no element"; - end if; - - if Parent.Container /= C then - raise Program_Error with "Parent cursor not in container"; - end if; - - return It : constant Child_Iterator := - Child_Iterator'(Limited_Controlled with - Container => C, - Subtree => Parent.Node) - do - B := B + 1; - end return; - end Iterate_Children; - - --------------------- - -- Iterate_Subtree -- - --------------------- - - function Iterate_Subtree - (Position : Cursor) - return Tree_Iterator_Interfaces.Forward_Iterator'Class - is - begin - if Position = No_Element then - raise Constraint_Error with "Position cursor has no element"; - end if; - - -- Implement Vet for multiway trees??? - -- pragma Assert (Vet (Position), "bad subtree cursor"); - - declare - B : Natural renames Position.Container.Busy; - begin - return It : constant Subtree_Iterator := - (Limited_Controlled with - Container => Position.Container, - Subtree => Position.Node) - do - B := B + 1; - end return; - end; - end Iterate_Subtree; - - procedure Iterate_Subtree - (Position : Cursor; - Process : not null access procedure (Position : Cursor)) - is - begin - if Position = No_Element then - raise Constraint_Error with "Position cursor has no element"; - end if; - - declare - B : Natural renames Position.Container.Busy; - - begin - B := B + 1; - - if Is_Root (Position) then - Iterate_Children (Position.Container, Position.Node, Process); - else - Iterate_Subtree (Position.Container, Position.Node, Process); - end if; - - B := B - 1; - - exception - when others => - B := B - 1; - raise; - end; - end Iterate_Subtree; - - procedure Iterate_Subtree - (Container : Tree_Access; - Subtree : Tree_Node_Access; - Process : not null access procedure (Position : Cursor)) - is - begin - -- This is a helper function to recursively iterate over all the nodes - -- in a subtree, in depth-first fashion. It first visits the root of the - -- subtree, then visits its children. - - Process (Cursor'(Container, Subtree)); - Iterate_Children (Container, Subtree, Process); - end Iterate_Subtree; - - ---------- - -- Last -- - ---------- - - overriding function Last (Object : Child_Iterator) return Cursor is - begin - return Last_Child (Cursor'(Object.Container, Object.Subtree)); - end Last; - - ---------------- - -- Last_Child -- - ---------------- - - function Last_Child (Parent : Cursor) return Cursor is - Node : Tree_Node_Access; - - begin - if Parent = No_Element then - raise Constraint_Error with "Parent cursor has no element"; - end if; - - Node := Parent.Node.Children.Last; - - if Node = null then - return No_Element; - end if; - - return (Parent.Container, Node); - end Last_Child; - - ------------------------ - -- Last_Child_Element -- - ------------------------ - - function Last_Child_Element (Parent : Cursor) return Element_Type is - begin - return Element (Last_Child (Parent)); - end Last_Child_Element; - - ---------- - -- Move -- - ---------- - - procedure Move (Target : in out Tree; Source : in out Tree) is - Node : Tree_Node_Access; - - begin - if Target'Address = Source'Address then - return; - end if; - - if Source.Busy > 0 then - raise Program_Error - with "attempt to tamper with cursors of Source (tree is busy)"; - end if; - - Target.Clear; -- checks busy bit - - Target.Root.Children := Source.Root.Children; - Source.Root.Children := Children_Type'(others => null); - - Node := Target.Root.Children.First; - while Node /= null loop - Node.Parent := Root_Node (Target); - Node := Node.Next; - end loop; - - Target.Count := Source.Count; - Source.Count := 0; - end Move; - - ---------- - -- Next -- - ---------- - - function Next - (Object : Subtree_Iterator; - Position : Cursor) return Cursor - is - Node : Tree_Node_Access; - - begin - if Position.Container = null then - return No_Element; - end if; - - if Position.Container /= Object.Container then - raise Program_Error with - "Position cursor of Next designates wrong tree"; - end if; - - Node := Position.Node; - - if Node.Children.First /= null then - return Cursor'(Object.Container, Node.Children.First); - end if; - - while Node /= Object.Subtree loop - if Node.Next /= null then - return Cursor'(Object.Container, Node.Next); - end if; - - Node := Node.Parent; - end loop; - - return No_Element; - end Next; - - function Next - (Object : Child_Iterator; - Position : Cursor) return Cursor - is - begin - if Position.Container = null then - return No_Element; - end if; - - if Position.Container /= Object.Container then - raise Program_Error with - "Position cursor of Next designates wrong tree"; - end if; - - return Next_Sibling (Position); - end Next; - - ------------------ - -- Next_Sibling -- - ------------------ - - function Next_Sibling (Position : Cursor) return Cursor is - begin - if Position = No_Element then - return No_Element; - end if; - - if Position.Node.Next = null then - return No_Element; - end if; - - return Cursor'(Position.Container, Position.Node.Next); - end Next_Sibling; - - procedure Next_Sibling (Position : in out Cursor) is - begin - Position := Next_Sibling (Position); - end Next_Sibling; - - ---------------- - -- Node_Count -- - ---------------- - - function Node_Count (Container : Tree) return Count_Type is - begin - -- Container.Count is the number of nodes we have actually allocated. We - -- cache the value specifically so this Node_Count operation can execute - -- in O(1) time, which makes it behave similarly to how the Length - -- selector function behaves for other containers. - -- - -- The cached node count value only describes the nodes we have - -- allocated; the root node itself is not included in that count. The - -- Node_Count operation returns a value that includes the root node - -- (because the RM says so), so we must add 1 to our cached value. - - return 1 + Container.Count; - end Node_Count; - - ------------ - -- Parent -- - ------------ - - function Parent (Position : Cursor) return Cursor is - begin - if Position = No_Element then - return No_Element; - end if; - - if Position.Node.Parent = null then - return No_Element; - end if; - - return Cursor'(Position.Container, Position.Node.Parent); - end Parent; - - ------------------- - -- Prepent_Child -- - ------------------- - - procedure Prepend_Child - (Container : in out Tree; - Parent : Cursor; - New_Item : Element_Type; - Count : Count_Type := 1) - is - First, Last : Tree_Node_Access; - Element : Element_Access; - - begin - if Parent = No_Element then - raise Constraint_Error with "Parent cursor has no element"; - end if; - - if Parent.Container /= Container'Unrestricted_Access then - raise Program_Error with "Parent cursor not in container"; - end if; - - if Count = 0 then - return; - end if; - - if Container.Busy > 0 then - raise Program_Error - with "attempt to tamper with cursors (tree is busy)"; - end if; - - Element := new Element_Type'(New_Item); - First := new Tree_Node_Type'(Parent => Parent.Node, - Element => Element, - others => <>); - - Last := First; - - for J in Count_Type'(2) .. Count loop - - -- Reclaim other nodes if Storage_Error. ??? - - Element := new Element_Type'(New_Item); - Last.Next := new Tree_Node_Type'(Parent => Parent.Node, - Prev => Last, - Element => Element, - others => <>); - - Last := Last.Next; - end loop; - - Insert_Subtree_List - (First => First, - Last => Last, - Parent => Parent.Node, - Before => Parent.Node.Children.First); - - -- In order for operation Node_Count to complete in O(1) time, we cache - -- the count value. Here we increment the total count by the number of - -- nodes we just inserted. - - Container.Count := Container.Count + Count; - end Prepend_Child; - - -------------- - -- Previous -- - -------------- - - overriding function Previous - (Object : Child_Iterator; - Position : Cursor) return Cursor - is - begin - if Position.Container = null then - return No_Element; - end if; - - if Position.Container /= Object.Container then - raise Program_Error with - "Position cursor of Previous designates wrong tree"; - end if; - - return Previous_Sibling (Position); - end Previous; - - ---------------------- - -- Previous_Sibling -- - ---------------------- - - function Previous_Sibling (Position : Cursor) return Cursor is - begin - if Position = No_Element then - return No_Element; - end if; - - if Position.Node.Prev = null then - return No_Element; - end if; - - return Cursor'(Position.Container, Position.Node.Prev); - end Previous_Sibling; - - procedure Previous_Sibling (Position : in out Cursor) is - begin - Position := Previous_Sibling (Position); - end Previous_Sibling; - - ------------------- - -- Query_Element -- - ------------------- - - procedure Query_Element - (Position : Cursor; - Process : not null access procedure (Element : Element_Type)) - is - begin - if Position = No_Element then - raise Constraint_Error with "Position cursor has no element"; - end if; - - if Is_Root (Position) then - raise Program_Error with "Position cursor designates root"; - end if; - - declare - T : Tree renames Position.Container.all'Unrestricted_Access.all; - B : Natural renames T.Busy; - L : Natural renames T.Lock; - - begin - B := B + 1; - L := L + 1; - - Process (Position.Node.Element.all); - - L := L - 1; - B := B - 1; - - exception - when others => - L := L - 1; - B := B - 1; - raise; - end; - end Query_Element; - - ---------- - -- Read -- - ---------- - - procedure Read - (Stream : not null access Root_Stream_Type'Class; - Container : out Tree) - is - procedure Read_Children (Subtree : Tree_Node_Access); - - function Read_Subtree - (Parent : Tree_Node_Access) return Tree_Node_Access; - - Total_Count : Count_Type'Base; - -- Value read from the stream that says how many elements follow - - Read_Count : Count_Type'Base; - -- Actual number of elements read from the stream - - ------------------- - -- Read_Children -- - ------------------- - - procedure Read_Children (Subtree : Tree_Node_Access) is - pragma Assert (Subtree /= null); - pragma Assert (Subtree.Children.First = null); - pragma Assert (Subtree.Children.Last = null); - - Count : Count_Type'Base; - -- Number of child subtrees - - C : Children_Type; - - begin - Count_Type'Read (Stream, Count); - - if Count < 0 then - raise Program_Error with "attempt to read from corrupt stream"; - end if; - - if Count = 0 then - return; - end if; - - C.First := Read_Subtree (Parent => Subtree); - C.Last := C.First; - - for J in Count_Type'(2) .. Count loop - C.Last.Next := Read_Subtree (Parent => Subtree); - C.Last.Next.Prev := C.Last; - C.Last := C.Last.Next; - end loop; - - -- Now that the allocation and reads have completed successfully, it - -- is safe to link the children to their parent. - - Subtree.Children := C; - end Read_Children; - - ------------------ - -- Read_Subtree -- - ------------------ - - function Read_Subtree - (Parent : Tree_Node_Access) return Tree_Node_Access - is - Element : constant Element_Access := - new Element_Type'(Element_Type'Input (Stream)); - - Subtree : constant Tree_Node_Access := - new Tree_Node_Type' - (Parent => Parent, - Element => Element, - others => <>); - - begin - Read_Count := Read_Count + 1; - - Read_Children (Subtree); - - return Subtree; - end Read_Subtree; - - -- Start of processing for Read - - begin - Container.Clear; -- checks busy bit - - Count_Type'Read (Stream, Total_Count); - - if Total_Count < 0 then - raise Program_Error with "attempt to read from corrupt stream"; - end if; - - if Total_Count = 0 then - return; - end if; - - Read_Count := 0; - - Read_Children (Root_Node (Container)); - - if Read_Count /= Total_Count then - raise Program_Error with "attempt to read from corrupt stream"; - end if; - - Container.Count := Total_Count; - end Read; - - procedure Read - (Stream : not null access Root_Stream_Type'Class; - Position : out Cursor) - is - begin - raise Program_Error with "attempt to read tree cursor from stream"; - end Read; - - procedure Read - (Stream : not null access Root_Stream_Type'Class; - Item : out Reference_Type) - is - begin - raise Program_Error with "attempt to stream reference"; - end Read; - - procedure Read - (Stream : not null access Root_Stream_Type'Class; - Item : out Constant_Reference_Type) - is - begin - raise Program_Error with "attempt to stream reference"; - end Read; - - --------------- - -- Reference -- - --------------- - - function Reference - (Container : aliased in out Tree; - Position : Cursor) return Reference_Type - is - begin - if Position.Container = null then - raise Constraint_Error with - "Position cursor has no element"; - end if; - - if Position.Container /= Container'Unrestricted_Access then - raise Program_Error with - "Position cursor designates wrong container"; - end if; - - if Position.Node = Root_Node (Container) then - raise Program_Error with "Position cursor designates root"; - end if; - - if Position.Node.Element = null then - raise Program_Error with "Node has no element"; - end if; - - -- Implement Vet for multiway tree??? - -- pragma Assert (Vet (Position), - -- "Position cursor in Constant_Reference is bad"); - - declare - C : Tree renames Position.Container.all; - B : Natural renames C.Busy; - L : Natural renames C.Lock; - begin - return R : constant Reference_Type := - (Element => Position.Node.Element.all'Access, - Control => (Controlled with Position.Container)) - do - B := B + 1; - L := L + 1; - end return; - end; - end Reference; - - -------------------- - -- Remove_Subtree -- - -------------------- - - procedure Remove_Subtree (Subtree : Tree_Node_Access) is - C : Children_Type renames Subtree.Parent.Children; - - begin - -- This is a utility operation to remove a subtree node from its - -- parent's list of children. - - if C.First = Subtree then - pragma Assert (Subtree.Prev = null); - - if C.Last = Subtree then - pragma Assert (Subtree.Next = null); - C.First := null; - C.Last := null; - - else - C.First := Subtree.Next; - C.First.Prev := null; - end if; - - elsif C.Last = Subtree then - pragma Assert (Subtree.Next = null); - C.Last := Subtree.Prev; - C.Last.Next := null; - - else - Subtree.Prev.Next := Subtree.Next; - Subtree.Next.Prev := Subtree.Prev; - end if; - end Remove_Subtree; - - ---------------------- - -- Replace_Element -- - ---------------------- - - procedure Replace_Element - (Container : in out Tree; - Position : Cursor; - New_Item : Element_Type) - is - E, X : Element_Access; - - begin - if Position = No_Element then - raise Constraint_Error with "Position cursor has no element"; - end if; - - if Position.Container /= Container'Unrestricted_Access then - raise Program_Error with "Position cursor not in container"; - end if; - - if Is_Root (Position) then - raise Program_Error with "Position cursor designates root"; - end if; - - if Container.Lock > 0 then - raise Program_Error - with "attempt to tamper with elements (tree is locked)"; - end if; - - E := new Element_Type'(New_Item); - - X := Position.Node.Element; - Position.Node.Element := E; - - Free_Element (X); - end Replace_Element; - - ------------------------------ - -- Reverse_Iterate_Children -- - ------------------------------ - - procedure Reverse_Iterate_Children - (Parent : Cursor; - Process : not null access procedure (Position : Cursor)) - is - begin - if Parent = No_Element then - raise Constraint_Error with "Parent cursor has no element"; - end if; - - declare - B : Natural renames Parent.Container.Busy; - C : Tree_Node_Access; - - begin - B := B + 1; - - C := Parent.Node.Children.Last; - while C /= null loop - Process (Position => Cursor'(Parent.Container, Node => C)); - C := C.Prev; - end loop; - - B := B - 1; - - exception - when others => - B := B - 1; - raise; - end; - end Reverse_Iterate_Children; - - ---------- - -- Root -- - ---------- - - function Root (Container : Tree) return Cursor is - begin - return (Container'Unrestricted_Access, Root_Node (Container)); - end Root; - - --------------- - -- Root_Node -- - --------------- - - function Root_Node (Container : Tree) return Tree_Node_Access is - begin - return Container.Root'Unrestricted_Access; - end Root_Node; - - --------------------- - -- Splice_Children -- - --------------------- - - procedure Splice_Children - (Target : in out Tree; - Target_Parent : Cursor; - Before : Cursor; - Source : in out Tree; - Source_Parent : Cursor) - is - Count : Count_Type; - - begin - if Target_Parent = No_Element then - raise Constraint_Error with "Target_Parent cursor has no element"; - end if; - - if Target_Parent.Container /= Target'Unrestricted_Access then - raise Program_Error - with "Target_Parent cursor not in Target container"; - end if; - - if Before /= No_Element then - if Before.Container /= Target'Unrestricted_Access then - raise Program_Error - with "Before cursor not in Target container"; - end if; - - if Before.Node.Parent /= Target_Parent.Node then - raise Constraint_Error - with "Before cursor not child of Target_Parent"; - end if; - end if; - - if Source_Parent = No_Element then - raise Constraint_Error with "Source_Parent cursor has no element"; - end if; - - if Source_Parent.Container /= Source'Unrestricted_Access then - raise Program_Error - with "Source_Parent cursor not in Source container"; - end if; - - if Target'Address = Source'Address then - if Target_Parent = Source_Parent then - return; - end if; - - if Target.Busy > 0 then - raise Program_Error - with "attempt to tamper with cursors (Target tree is busy)"; - end if; - - if Is_Reachable (From => Target_Parent.Node, - To => Source_Parent.Node) - then - raise Constraint_Error - with "Source_Parent is ancestor of Target_Parent"; - end if; - - Splice_Children - (Target_Parent => Target_Parent.Node, - Before => Before.Node, - Source_Parent => Source_Parent.Node); - - return; - end if; - - if Target.Busy > 0 then - raise Program_Error - with "attempt to tamper with cursors (Target tree is busy)"; - end if; - - if Source.Busy > 0 then - raise Program_Error - with "attempt to tamper with cursors (Source tree is busy)"; - end if; - - -- We cache the count of the nodes we have allocated, so that operation - -- Node_Count can execute in O(1) time. But that means we must count the - -- nodes in the subtree we remove from Source and insert into Target, in - -- order to keep the count accurate. - - Count := Subtree_Node_Count (Source_Parent.Node); - pragma Assert (Count >= 1); - - Count := Count - 1; -- because Source_Parent node does not move - - Splice_Children - (Target_Parent => Target_Parent.Node, - Before => Before.Node, - Source_Parent => Source_Parent.Node); - - Source.Count := Source.Count - Count; - Target.Count := Target.Count + Count; - end Splice_Children; - - procedure Splice_Children - (Container : in out Tree; - Target_Parent : Cursor; - Before : Cursor; - Source_Parent : Cursor) - is - begin - if Target_Parent = No_Element then - raise Constraint_Error with "Target_Parent cursor has no element"; - end if; - - if Target_Parent.Container /= Container'Unrestricted_Access then - raise Program_Error - with "Target_Parent cursor not in container"; - end if; - - if Before /= No_Element then - if Before.Container /= Container'Unrestricted_Access then - raise Program_Error - with "Before cursor not in container"; - end if; - - if Before.Node.Parent /= Target_Parent.Node then - raise Constraint_Error - with "Before cursor not child of Target_Parent"; - end if; - end if; - - if Source_Parent = No_Element then - raise Constraint_Error with "Source_Parent cursor has no element"; - end if; - - if Source_Parent.Container /= Container'Unrestricted_Access then - raise Program_Error - with "Source_Parent cursor not in container"; - end if; - - if Target_Parent = Source_Parent then - return; - end if; - - if Container.Busy > 0 then - raise Program_Error - with "attempt to tamper with cursors (tree is busy)"; - end if; - - if Is_Reachable (From => Target_Parent.Node, - To => Source_Parent.Node) - then - raise Constraint_Error - with "Source_Parent is ancestor of Target_Parent"; - end if; - - Splice_Children - (Target_Parent => Target_Parent.Node, - Before => Before.Node, - Source_Parent => Source_Parent.Node); - end Splice_Children; - - procedure Splice_Children - (Target_Parent : Tree_Node_Access; - Before : Tree_Node_Access; - Source_Parent : Tree_Node_Access) - is - CC : constant Children_Type := Source_Parent.Children; - C : Tree_Node_Access; - - begin - -- This is a utility operation to remove the children from Source parent - -- and insert them into Target parent. - - Source_Parent.Children := Children_Type'(others => null); - - -- Fix up the Parent pointers of each child to designate its new Target - -- parent. - - C := CC.First; - while C /= null loop - C.Parent := Target_Parent; - C := C.Next; - end loop; - - Insert_Subtree_List - (First => CC.First, - Last => CC.Last, - Parent => Target_Parent, - Before => Before); - end Splice_Children; - - -------------------- - -- Splice_Subtree -- - -------------------- - - procedure Splice_Subtree - (Target : in out Tree; - Parent : Cursor; - Before : Cursor; - Source : in out Tree; - Position : in out Cursor) - is - Subtree_Count : Count_Type; - - begin - if Parent = No_Element then - raise Constraint_Error with "Parent cursor has no element"; - end if; - - if Parent.Container /= Target'Unrestricted_Access then - raise Program_Error with "Parent cursor not in Target container"; - end if; - - if Before /= No_Element then - if Before.Container /= Target'Unrestricted_Access then - raise Program_Error with "Before cursor not in Target container"; - end if; - - if Before.Node.Parent /= Parent.Node then - raise Constraint_Error with "Before cursor not child of Parent"; - end if; - end if; - - if Position = No_Element then - raise Constraint_Error with "Position cursor has no element"; - end if; - - if Position.Container /= Source'Unrestricted_Access then - raise Program_Error with "Position cursor not in Source container"; - end if; - - if Is_Root (Position) then - raise Program_Error with "Position cursor designates root"; - end if; - - if Target'Address = Source'Address then - if Position.Node.Parent = Parent.Node then - if Position.Node = Before.Node then - return; - end if; - - if Position.Node.Next = Before.Node then - return; - end if; - end if; - - if Target.Busy > 0 then - raise Program_Error - with "attempt to tamper with cursors (Target tree is busy)"; - end if; - - if Is_Reachable (From => Parent.Node, To => Position.Node) then - raise Constraint_Error with "Position is ancestor of Parent"; - end if; - - Remove_Subtree (Position.Node); - - Position.Node.Parent := Parent.Node; - Insert_Subtree_Node (Position.Node, Parent.Node, Before.Node); - - return; - end if; - - if Target.Busy > 0 then - raise Program_Error - with "attempt to tamper with cursors (Target tree is busy)"; - end if; - - if Source.Busy > 0 then - raise Program_Error - with "attempt to tamper with cursors (Source tree is busy)"; - end if; - - -- This is an unfortunate feature of this API: we must count the nodes - -- in the subtree that we remove from the source tree, which is an O(n) - -- operation. It would have been better if the Tree container did not - -- have a Node_Count selector; a user that wants the number of nodes in - -- the tree could simply call Subtree_Node_Count, with the understanding - -- that such an operation is O(n). - -- - -- Of course, we could choose to implement the Node_Count selector as an - -- O(n) operation, which would turn this splice operation into an O(1) - -- operation. ??? - - Subtree_Count := Subtree_Node_Count (Position.Node); - pragma Assert (Subtree_Count <= Source.Count); - - Remove_Subtree (Position.Node); - Source.Count := Source.Count - Subtree_Count; - - Position.Node.Parent := Parent.Node; - Insert_Subtree_Node (Position.Node, Parent.Node, Before.Node); - - Target.Count := Target.Count + Subtree_Count; - - Position.Container := Target'Unrestricted_Access; - end Splice_Subtree; - - procedure Splice_Subtree - (Container : in out Tree; - Parent : Cursor; - Before : Cursor; - Position : Cursor) - is - begin - if Parent = No_Element then - raise Constraint_Error with "Parent cursor has no element"; - end if; - - if Parent.Container /= Container'Unrestricted_Access then - raise Program_Error with "Parent cursor not in container"; - end if; - - if Before /= No_Element then - if Before.Container /= Container'Unrestricted_Access then - raise Program_Error with "Before cursor not in container"; - end if; - - if Before.Node.Parent /= Parent.Node then - raise Constraint_Error with "Before cursor not child of Parent"; - end if; - end if; - - if Position = No_Element then - raise Constraint_Error with "Position cursor has no element"; - end if; - - if Position.Container /= Container'Unrestricted_Access then - raise Program_Error with "Position cursor not in container"; - end if; - - if Is_Root (Position) then - - -- Should this be PE instead? Need ARG confirmation. ??? - - raise Constraint_Error with "Position cursor designates root"; - end if; - - if Position.Node.Parent = Parent.Node then - if Position.Node = Before.Node then - return; - end if; - - if Position.Node.Next = Before.Node then - return; - end if; - end if; - - if Container.Busy > 0 then - raise Program_Error - with "attempt to tamper with cursors (tree is busy)"; - end if; - - if Is_Reachable (From => Parent.Node, To => Position.Node) then - raise Constraint_Error with "Position is ancestor of Parent"; - end if; - - Remove_Subtree (Position.Node); - - Position.Node.Parent := Parent.Node; - Insert_Subtree_Node (Position.Node, Parent.Node, Before.Node); - end Splice_Subtree; - - ------------------------ - -- Subtree_Node_Count -- - ------------------------ - - function Subtree_Node_Count (Position : Cursor) return Count_Type is - begin - if Position = No_Element then - return 0; - end if; - - return Subtree_Node_Count (Position.Node); - end Subtree_Node_Count; - - function Subtree_Node_Count - (Subtree : Tree_Node_Access) return Count_Type - is - Result : Count_Type; - Node : Tree_Node_Access; - - begin - Result := 1; - Node := Subtree.Children.First; - while Node /= null loop - Result := Result + Subtree_Node_Count (Node); - Node := Node.Next; - end loop; - - return Result; - end Subtree_Node_Count; - - ---------- - -- Swap -- - ---------- - - procedure Swap - (Container : in out Tree; - I, J : Cursor) - is - begin - if I = No_Element then - raise Constraint_Error with "I cursor has no element"; - end if; - - if I.Container /= Container'Unrestricted_Access then - raise Program_Error with "I cursor not in container"; - end if; - - if Is_Root (I) then - raise Program_Error with "I cursor designates root"; - end if; - - if I = J then -- make this test sooner??? - return; - end if; - - if J = No_Element then - raise Constraint_Error with "J cursor has no element"; - end if; - - if J.Container /= Container'Unrestricted_Access then - raise Program_Error with "J cursor not in container"; - end if; - - if Is_Root (J) then - raise Program_Error with "J cursor designates root"; - end if; - - if Container.Lock > 0 then - raise Program_Error - with "attempt to tamper with elements (tree is locked)"; - end if; - - declare - EI : constant Element_Access := I.Node.Element; - - begin - I.Node.Element := J.Node.Element; - J.Node.Element := EI; - end; - end Swap; - - -------------------- - -- Update_Element -- - -------------------- - - procedure Update_Element - (Container : in out Tree; - Position : Cursor; - Process : not null access procedure (Element : in out Element_Type)) - is - begin - if Position = No_Element then - raise Constraint_Error with "Position cursor has no element"; - end if; - - if Position.Container /= Container'Unrestricted_Access then - raise Program_Error with "Position cursor not in container"; - end if; - - if Is_Root (Position) then - raise Program_Error with "Position cursor designates root"; - end if; - - declare - T : Tree renames Position.Container.all'Unrestricted_Access.all; - B : Natural renames T.Busy; - L : Natural renames T.Lock; - - begin - B := B + 1; - L := L + 1; - - Process (Position.Node.Element.all); - - L := L - 1; - B := B - 1; - - exception - when others => - L := L - 1; - B := B - 1; - raise; - end; - end Update_Element; - - ----------- - -- Write -- - ----------- - - procedure Write - (Stream : not null access Root_Stream_Type'Class; - Container : Tree) - is - procedure Write_Children (Subtree : Tree_Node_Access); - procedure Write_Subtree (Subtree : Tree_Node_Access); - - -------------------- - -- Write_Children -- - -------------------- - - procedure Write_Children (Subtree : Tree_Node_Access) is - CC : Children_Type renames Subtree.Children; - C : Tree_Node_Access; - - begin - Count_Type'Write (Stream, Child_Count (CC)); - - C := CC.First; - while C /= null loop - Write_Subtree (C); - C := C.Next; - end loop; - end Write_Children; - - ------------------- - -- Write_Subtree -- - ------------------- - - procedure Write_Subtree (Subtree : Tree_Node_Access) is - begin - Element_Type'Output (Stream, Subtree.Element.all); - Write_Children (Subtree); - end Write_Subtree; - - -- Start of processing for Write - - begin - Count_Type'Write (Stream, Container.Count); - - if Container.Count = 0 then - return; - end if; - - Write_Children (Root_Node (Container)); - end Write; - - procedure Write - (Stream : not null access Root_Stream_Type'Class; - Position : Cursor) - is - begin - raise Program_Error with "attempt to write tree cursor to stream"; - end Write; - - procedure Write - (Stream : not null access Root_Stream_Type'Class; - Item : Reference_Type) - is - begin - raise Program_Error with "attempt to stream reference"; - end Write; - - procedure Write - (Stream : not null access Root_Stream_Type'Class; - Item : Constant_Reference_Type) - is - begin - raise Program_Error with "attempt to stream reference"; - end Write; - -end Ada.Containers.Indefinite_Multiway_Trees; |