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------------------------------------------------------------------------------
-- --
-- GNAT LIBRARY COMPONENTS --
-- --
-- A D A . C O N T A I N E R S . B O U N D E D _ V E C T O R S --
-- --
-- B o d y --
-- --
-- Copyright (C) 2004-2021, 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.Containers.Generic_Array_Sort;
with System; use type System.Address;
with System.Put_Images;
package body Ada.Containers.Bounded_Vectors is
pragma Warnings (Off, "variable ""Busy*"" is not referenced");
pragma Warnings (Off, "variable ""Lock*"" is not referenced");
-- See comment in Ada.Containers.Helpers
-----------------------
-- Local Subprograms --
-----------------------
function To_Array_Index (Index : Index_Type'Base) return Count_Type'Base;
---------
-- "&" --
---------
function "&" (Left, Right : Vector) return Vector is
LN : constant Count_Type := Length (Left);
RN : constant Count_Type := Length (Right);
N : Count_Type'Base; -- length of result
J : Count_Type'Base; -- for computing intermediate index values
Last : Index_Type'Base; -- Last index of result
begin
-- We decide that the capacity of the result is the sum of the lengths
-- of the vector parameters. We could decide to make it larger, but we
-- have no basis for knowing how much larger, so we just allocate the
-- minimum amount of storage.
-- Here we handle the easy cases first, when one of the vector
-- parameters is empty. (We say "easy" because there's nothing to
-- compute, that can potentially overflow.)
if LN = 0 then
if RN = 0 then
return Empty_Vector;
end if;
return Vector'(Capacity => RN,
Elements => Right.Elements (1 .. RN),
Last => Right.Last,
others => <>);
end if;
if RN = 0 then
return Vector'(Capacity => LN,
Elements => Left.Elements (1 .. LN),
Last => Left.Last,
others => <>);
end if;
-- Neither of the vector parameters is empty, so must compute the length
-- of the result vector and its last index. (This is the harder case,
-- because our computations must avoid overflow.)
-- There are two constraints we need to satisfy. The first constraint is
-- that a container cannot have more than Count_Type'Last elements, so
-- we must check the sum of the combined lengths. Note that we cannot
-- simply add the lengths, because of the possibility of overflow.
if Checks and then LN > Count_Type'Last - RN then
raise Constraint_Error with "new length is out of range";
end if;
-- It is now safe to compute the length of the new vector, without fear
-- of overflow.
N := LN + RN;
-- The second constraint is that the new Last index value cannot
-- exceed Index_Type'Last. We use the wider of Index_Type'Base and
-- Count_Type'Base as the type for intermediate values.
if Index_Type'Base'Last >= Count_Type'Pos (Count_Type'Last) then
-- We perform a two-part test. First we determine whether the
-- computed Last value lies in the base range of the type, and then
-- determine whether it lies in the range of the index (sub)type.
-- Last must satisfy this relation:
-- First + Length - 1 <= Last
-- We regroup terms:
-- First - 1 <= Last - Length
-- Which can rewrite as:
-- No_Index <= Last - Length
if Checks and then
Index_Type'Base'Last - Index_Type'Base (N) < No_Index
then
raise Constraint_Error with "new length is out of range";
end if;
-- We now know that the computed value of Last is within the base
-- range of the type, so it is safe to compute its value:
Last := No_Index + Index_Type'Base (N);
-- Finally we test whether the value is within the range of the
-- generic actual index subtype:
if Checks and then Last > Index_Type'Last then
raise Constraint_Error with "new length is out of range";
end if;
elsif Index_Type'First <= 0 then
-- Here we can compute Last directly, in the normal way. We know that
-- No_Index is less than 0, so there is no danger of overflow when
-- adding the (positive) value of length.
J := Count_Type'Base (No_Index) + N; -- Last
if Checks and then J > Count_Type'Base (Index_Type'Last) then
raise Constraint_Error with "new length is out of range";
end if;
-- We know that the computed value (having type Count_Type) of Last
-- is within the range of the generic actual index subtype, so it is
-- safe to convert to Index_Type:
Last := Index_Type'Base (J);
else
-- Here Index_Type'First (and Index_Type'Last) is positive, so we
-- must test the length indirectly (by working backwards from the
-- largest possible value of Last), in order to prevent overflow.
J := Count_Type'Base (Index_Type'Last) - N; -- No_Index
if Checks and then J < Count_Type'Base (No_Index) then
raise Constraint_Error with "new length is out of range";
end if;
-- We have determined that the result length would not create a Last
-- index value outside of the range of Index_Type, so we can now
-- safely compute its value.
Last := Index_Type'Base (Count_Type'Base (No_Index) + N);
end if;
declare
LE : Elements_Array renames Left.Elements (1 .. LN);
RE : Elements_Array renames Right.Elements (1 .. RN);
begin
return Vector'(Capacity => N,
Elements => LE & RE,
Last => Last,
others => <>);
end;
end "&";
function "&" (Left : Vector; Right : Element_Type) return Vector is
LN : constant Count_Type := Length (Left);
begin
-- We decide that the capacity of the result is the sum of the lengths
-- of the parameters. We could decide to make it larger, but we have no
-- basis for knowing how much larger, so we just allocate the minimum
-- amount of storage.
-- We must compute the length of the result vector and its last index,
-- but in such a way that overflow is avoided. We must satisfy two
-- constraints: the new length cannot exceed Count_Type'Last, and the
-- new Last index cannot exceed Index_Type'Last.
if Checks and then LN = Count_Type'Last then
raise Constraint_Error with "new length is out of range";
end if;
if Checks and then Left.Last >= Index_Type'Last then
raise Constraint_Error with "new length is out of range";
end if;
return Vector'(Capacity => LN + 1,
Elements => Left.Elements (1 .. LN) & Right,
Last => Left.Last + 1,
others => <>);
end "&";
function "&" (Left : Element_Type; Right : Vector) return Vector is
RN : constant Count_Type := Length (Right);
begin
-- We decide that the capacity of the result is the sum of the lengths
-- of the parameters. We could decide to make it larger, but we have no
-- basis for knowing how much larger, so we just allocate the minimum
-- amount of storage.
-- We compute the length of the result vector and its last index, but in
-- such a way that overflow is avoided. We must satisfy two constraints:
-- the new length cannot exceed Count_Type'Last, and the new Last index
-- cannot exceed Index_Type'Last.
if Checks and then RN = Count_Type'Last then
raise Constraint_Error with "new length is out of range";
end if;
if Checks and then Right.Last >= Index_Type'Last then
raise Constraint_Error with "new length is out of range";
end if;
return Vector'(Capacity => 1 + RN,
Elements => Left & Right.Elements (1 .. RN),
Last => Right.Last + 1,
others => <>);
end "&";
function "&" (Left, Right : Element_Type) return Vector is
begin
-- We decide that the capacity of the result is the sum of the lengths
-- of the parameters. We could decide to make it larger, but we have no
-- basis for knowing how much larger, so we just allocate the minimum
-- amount of storage.
-- We must compute the length of the result vector and its last index,
-- but in such a way that overflow is avoided. We must satisfy two
-- constraints: the new length cannot exceed Count_Type'Last (here, we
-- know that that condition is satisfied), and the new Last index cannot
-- exceed Index_Type'Last.
if Checks and then Index_Type'First >= Index_Type'Last then
raise Constraint_Error with "new length is out of range";
end if;
return Vector'(Capacity => 2,
Elements => (Left, Right),
Last => Index_Type'First + 1,
others => <>);
end "&";
---------
-- "=" --
---------
overriding function "=" (Left, Right : Vector) return Boolean is
begin
if Left.Last /= Right.Last then
return False;
end if;
if Left.Length = 0 then
return True;
end if;
declare
-- Per AI05-0022, the container implementation is required to detect
-- element tampering by a generic actual subprogram.
Lock_Left : With_Lock (Left.TC'Unrestricted_Access);
Lock_Right : With_Lock (Right.TC'Unrestricted_Access);
begin
for J in Count_Type range 1 .. Left.Length loop
if Left.Elements (J) /= Right.Elements (J) then
return False;
end if;
end loop;
end;
return True;
end "=";
------------
-- Assign --
------------
procedure Assign (Target : in out Vector; Source : Vector) is
begin
if Target'Address = Source'Address then
return;
end if;
if Checks and then Target.Capacity < Source.Length then
raise Capacity_Error -- ???
with "Target capacity is less than Source length";
end if;
Target.Clear;
Target.Elements (1 .. Source.Length) :=
Source.Elements (1 .. Source.Length);
Target.Last := Source.Last;
end Assign;
------------
-- Append --
------------
procedure Append
(Container : in out Vector;
New_Item : Element_Type;
Count : Count_Type)
is
begin
if Count = 0 then
return;
end if;
if Checks and then Container.Last >= Index_Type'Last then
raise Constraint_Error with "vector is already at its maximum length";
end if;
Container.Insert (Container.Last + 1, New_Item, Count);
end Append;
-------------------
-- Append_Vector --
-------------------
procedure Append_Vector (Container : in out Vector; New_Item : Vector) is
begin
if New_Item.Is_Empty then
return;
end if;
if Checks and then Container.Last >= Index_Type'Last then
raise Constraint_Error with "vector is already at its maximum length";
end if;
Container.Insert_Vector (Container.Last + 1, New_Item);
end Append_Vector;
------------
-- Append --
------------
procedure Append (Container : in out Vector;
New_Item : Element_Type)
is
begin
Insert (Container, Last_Index (Container) + 1, New_Item, 1);
end Append;
--------------
-- Capacity --
--------------
function Capacity (Container : Vector) return Count_Type is
begin
return Container.Elements'Length;
end Capacity;
-----------
-- Clear --
-----------
procedure Clear (Container : in out Vector) is
begin
TC_Check (Container.TC);
Container.Last := No_Index;
end Clear;
------------------------
-- Constant_Reference --
------------------------
function Constant_Reference
(Container : aliased Vector;
Position : Cursor) return Constant_Reference_Type
is
begin
if Checks and then Position.Container = null then
raise Constraint_Error with "Position cursor has no element";
end if;
if Checks and then Position.Container /= Container'Unrestricted_Access
then
raise Program_Error with "Position cursor denotes wrong container";
end if;
if Checks and then Position.Index > Position.Container.Last then
raise Constraint_Error with "Position cursor is out of range";
end if;
declare
A : Elements_Array renames Container.Elements;
J : constant Count_Type := To_Array_Index (Position.Index);
TC : constant Tamper_Counts_Access :=
Container.TC'Unrestricted_Access;
begin
return R : constant Constant_Reference_Type :=
(Element => A (J)'Unchecked_Access,
Control => (Controlled with TC))
do
Busy (TC.all);
end return;
end;
end Constant_Reference;
function Constant_Reference
(Container : aliased Vector;
Index : Index_Type) return Constant_Reference_Type
is
begin
if Checks and then Index > Container.Last then
raise Constraint_Error with "Index is out of range";
end if;
declare
A : Elements_Array renames Container.Elements;
J : constant Count_Type := To_Array_Index (Index);
TC : constant Tamper_Counts_Access :=
Container.TC'Unrestricted_Access;
begin
return R : constant Constant_Reference_Type :=
(Element => A (J)'Unchecked_Access,
Control => (Controlled with TC))
do
Busy (TC.all);
end return;
end;
end Constant_Reference;
--------------
-- Contains --
--------------
function Contains
(Container : Vector;
Item : Element_Type) return Boolean
is
begin
return Find_Index (Container, Item) /= No_Index;
end Contains;
----------
-- Copy --
----------
function Copy
(Source : Vector;
Capacity : Count_Type := 0) return Vector
is
C : constant Count_Type :=
(if Capacity = 0 then Source.Length
else Capacity);
begin
if Checks and then C < Source.Length then
raise Capacity_Error with "Capacity too small";
end if;
return Target : Vector (C) do
Target.Elements (1 .. Source.Length) :=
Source.Elements (1 .. Source.Length);
Target.Last := Source.Last;
end return;
end Copy;
------------
-- Delete --
------------
procedure Delete
(Container : in out Vector;
Index : Extended_Index;
Count : Count_Type := 1)
is
Old_Last : constant Index_Type'Base := Container.Last;
Old_Len : constant Count_Type := Container.Length;
New_Last : Index_Type'Base;
Count2 : Count_Type'Base; -- count of items from Index to Old_Last
Off : Count_Type'Base; -- Index expressed as offset from IT'First
begin
TC_Check (Container.TC);
-- Delete removes items from the vector, the number of which is the
-- minimum of the specified Count and the items (if any) that exist from
-- Index to Container.Last. There are no constraints on the specified
-- value of Count (it can be larger than what's available at this
-- position in the vector, for example), but there are constraints on
-- the allowed values of the Index.
-- As a precondition on the generic actual Index_Type, the base type
-- must include Index_Type'Pred (Index_Type'First); this is the value
-- that Container.Last assumes when the vector is empty. However, we do
-- not allow that as the value for Index when specifying which items
-- should be deleted, so we must manually check. (That the user is
-- allowed to specify the value at all here is a consequence of the
-- declaration of the Extended_Index subtype, which includes the values
-- in the base range that immediately precede and immediately follow the
-- values in the Index_Type.)
if Checks and then Index < Index_Type'First then
raise Constraint_Error with "Index is out of range (too small)";
end if;
-- We do allow a value greater than Container.Last to be specified as
-- the Index, but only if it's immediately greater. This allows the
-- corner case of deleting no items from the back end of the vector to
-- be treated as a no-op. (It is assumed that specifying an index value
-- greater than Last + 1 indicates some deeper flaw in the caller's
-- algorithm, so that case is treated as a proper error.)
if Index > Old_Last then
if Checks and then Index > Old_Last + 1 then
raise Constraint_Error with "Index is out of range (too large)";
end if;
return;
end if;
-- Here and elsewhere we treat deleting 0 items from the container as a
-- no-op, even when the container is busy, so we simply return.
if Count = 0 then
return;
end if;
-- The tampering bits exist to prevent an item from being deleted (or
-- otherwise harmfully manipulated) while it is being visited. Query,
-- Update, and Iterate increment the busy count on entry, and decrement
-- the count on exit. Delete checks the count to determine whether it is
-- being called while the associated callback procedure is executing.
-- We first calculate what's available for deletion starting at
-- Index. Here and elsewhere we use the wider of Index_Type'Base and
-- Count_Type'Base as the type for intermediate values. (See function
-- Length for more information.)
if Count_Type'Base'Last >= Index_Type'Pos (Index_Type'Base'Last) then
Count2 := Count_Type'Base (Old_Last) - Count_Type'Base (Index) + 1;
else
Count2 := Count_Type'Base (Old_Last - Index + 1);
end if;
-- If more elements are requested (Count) for deletion than are
-- available (Count2) for deletion beginning at Index, then everything
-- from Index is deleted. There are no elements to slide down, and so
-- all we need to do is set the value of Container.Last.
if Count >= Count2 then
Container.Last := Index - 1;
return;
end if;
-- There are some elements aren't being deleted (the requested count was
-- less than the available count), so we must slide them down to
-- Index. We first calculate the index values of the respective array
-- slices, using the wider of Index_Type'Base and Count_Type'Base as the
-- type for intermediate calculations.
if Index_Type'Base'Last >= Count_Type'Pos (Count_Type'Last) then
Off := Count_Type'Base (Index - Index_Type'First);
New_Last := Old_Last - Index_Type'Base (Count);
else
Off := Count_Type'Base (Index) - Count_Type'Base (Index_Type'First);
New_Last := Index_Type'Base (Count_Type'Base (Old_Last) - Count);
end if;
-- The array index values for each slice have already been determined,
-- so we just slide down to Index the elements that weren't deleted.
declare
EA : Elements_Array renames Container.Elements;
Idx : constant Count_Type := EA'First + Off;
begin
EA (Idx .. Old_Len - Count) := EA (Idx + Count .. Old_Len);
Container.Last := New_Last;
end;
end Delete;
procedure Delete
(Container : in out Vector;
Position : in out Cursor;
Count : Count_Type := 1)
is
pragma Warnings (Off, Position);
begin
if Checks and then Position.Container = null then
raise Constraint_Error with "Position cursor has no element";
end if;
if Checks and then Position.Container /= Container'Unrestricted_Access
then
raise Program_Error with "Position cursor denotes wrong container";
end if;
if Checks and then Position.Index > Container.Last then
raise Program_Error with "Position index is out of range";
end if;
Delete (Container, Position.Index, Count);
Position := No_Element;
end Delete;
------------------
-- Delete_First --
------------------
procedure Delete_First
(Container : in out Vector;
Count : Count_Type := 1)
is
begin
if Count = 0 then
return;
elsif Count >= Length (Container) then
Clear (Container);
return;
else
Delete (Container, Index_Type'First, Count);
end if;
end Delete_First;
-----------------
-- Delete_Last --
-----------------
procedure Delete_Last
(Container : in out Vector;
Count : Count_Type := 1)
is
begin
-- The tampering bits exist to prevent an item from being deleted (or
-- otherwise harmfully manipulated) while it is being visited. Query,
-- Update, and Iterate increment the busy count on entry, and decrement
-- the count on exit. Delete_Last checks the count to determine whether
-- it is being called while the associated callback procedure is
-- executing.
TC_Check (Container.TC);
if Count = 0 then
return;
end if;
-- There is no restriction on how large Count can be when deleting
-- items. If it is equal or greater than the current length, then this
-- is equivalent to clearing the vector. (In particular, there's no need
-- for us to actually calculate the new value for Last.)
-- If the requested count is less than the current length, then we must
-- calculate the new value for Last. For the type we use the widest of
-- Index_Type'Base and Count_Type'Base for the intermediate values of
-- our calculation. (See the comments in Length for more information.)
if Count >= Container.Length then
Container.Last := No_Index;
elsif Index_Type'Base'Last >= Count_Type'Pos (Count_Type'Last) then
Container.Last := Container.Last - Index_Type'Base (Count);
else
Container.Last :=
Index_Type'Base (Count_Type'Base (Container.Last) - Count);
end if;
end Delete_Last;
-------------
-- Element --
-------------
function Element
(Container : Vector;
Index : Index_Type) return Element_Type
is
begin
if Checks and then Index > Container.Last then
raise Constraint_Error with "Index is out of range";
else
return Container.Elements (To_Array_Index (Index));
end if;
end Element;
function Element (Position : Cursor) return Element_Type is
begin
if Checks and then Position.Container = null then
raise Constraint_Error with "Position cursor has no element";
else
return Position.Container.Element (Position.Index);
end if;
end Element;
-----------
-- Empty --
-----------
function Empty (Capacity : Count_Type := 10) return Vector is
begin
return Result : Vector (Capacity) do
Reserve_Capacity (Result, Capacity);
end return;
end Empty;
--------------
-- Finalize --
--------------
procedure Finalize (Object : in out Iterator) is
begin
Unbusy (Object.Container.TC);
end Finalize;
----------
-- Find --
----------
function Find
(Container : Vector;
Item : Element_Type;
Position : Cursor := No_Element) return Cursor
is
begin
if Position.Container /= null then
if Checks and then Position.Container /= Container'Unrestricted_Access
then
raise Program_Error with "Position cursor denotes wrong container";
end if;
if Checks and then Position.Index > Container.Last then
raise Program_Error with "Position index is out of range";
end if;
end if;
-- Per AI05-0022, the container implementation is required to detect
-- element tampering by a generic actual subprogram.
declare
Lock : With_Lock (Container.TC'Unrestricted_Access);
begin
for J in Position.Index .. Container.Last loop
if Container.Elements (To_Array_Index (J)) = Item then
return Cursor'(Container'Unrestricted_Access, J);
end if;
end loop;
return No_Element;
end;
end Find;
----------------
-- Find_Index --
----------------
function Find_Index
(Container : Vector;
Item : Element_Type;
Index : Index_Type := Index_Type'First) return Extended_Index
is
-- Per AI05-0022, the container implementation is required to detect
-- element tampering by a generic actual subprogram.
Lock : With_Lock (Container.TC'Unrestricted_Access);
begin
for Indx in Index .. Container.Last loop
if Container.Elements (To_Array_Index (Indx)) = Item then
return Indx;
end if;
end loop;
return No_Index;
end Find_Index;
-----------
-- First --
-----------
function First (Container : Vector) return Cursor is
begin
if Is_Empty (Container) then
return No_Element;
else
return (Container'Unrestricted_Access, Index_Type'First);
end if;
end First;
function First (Object : Iterator) return Cursor is
begin
-- The value of the iterator object's Index component influences the
-- behavior of the First (and Last) selector function.
-- When the Index component is No_Index, this means the iterator
-- object was constructed without a start expression, in which case the
-- (forward) iteration starts from the (logical) beginning of the entire
-- sequence of items (corresponding to Container.First, for a forward
-- iterator).
-- Otherwise, this is iteration over a partial sequence of items.
-- When the Index component isn't No_Index, the iterator object was
-- constructed with a start expression, that specifies the position
-- from which the (forward) partial iteration begins.
if Object.Index = No_Index then
return First (Object.Container.all);
else
return Cursor'(Object.Container, Object.Index);
end if;
end First;
-------------------
-- First_Element --
-------------------
function First_Element (Container : Vector) return Element_Type is
begin
if Checks and then Container.Last = No_Index then
raise Constraint_Error with "Container is empty";
end if;
return Container.Elements (To_Array_Index (Index_Type'First));
end First_Element;
-----------------
-- First_Index --
-----------------
function First_Index (Container : Vector) return Index_Type is
pragma Unreferenced (Container);
begin
return Index_Type'First;
end First_Index;
-----------------
-- New_Vector --
-----------------
function New_Vector (First, Last : Index_Type) return Vector
is
begin
return (To_Vector (Count_Type (Last - First + 1)));
end New_Vector;
---------------------
-- Generic_Sorting --
---------------------
package body Generic_Sorting is
---------------
-- Is_Sorted --
---------------
function Is_Sorted (Container : Vector) return Boolean is
begin
if Container.Last <= Index_Type'First then
return True;
end if;
-- Per AI05-0022, the container implementation is required to detect
-- element tampering by a generic actual subprogram.
declare
Lock : With_Lock (Container.TC'Unrestricted_Access);
EA : Elements_Array renames Container.Elements;
begin
for J in 1 .. Container.Length - 1 loop
if EA (J + 1) < EA (J) then
return False;
end if;
end loop;
return True;
end;
end Is_Sorted;
-----------
-- Merge --
-----------
procedure Merge (Target, Source : in out Vector) is
I, J : Count_Type;
begin
-- The semantics of Merge changed slightly per AI05-0021. It was
-- originally the case that if Target and Source denoted the same
-- container object, then the GNAT implementation of Merge did
-- nothing. However, it was argued that RM05 did not precisely
-- specify the semantics for this corner case. The decision of the
-- ARG was that if Target and Source denote the same non-empty
-- container object, then Program_Error is raised.
if Source.Is_Empty then
return;
end if;
TC_Check (Source.TC);
if Checks and then Target'Address = Source'Address then
raise Program_Error with
"Target and Source denote same non-empty container";
end if;
if Target.Is_Empty then
Move (Target => Target, Source => Source);
return;
end if;
I := Target.Length;
Target.Set_Length (I + Source.Length);
-- Per AI05-0022, the container implementation is required to detect
-- element tampering by a generic actual subprogram.
declare
TA : Elements_Array renames Target.Elements;
SA : Elements_Array renames Source.Elements;
Lock_Target : With_Lock (Target.TC'Unchecked_Access);
Lock_Source : With_Lock (Source.TC'Unchecked_Access);
begin
J := Target.Length;
while not Source.Is_Empty loop
pragma Assert (Source.Length <= 1
or else not (SA (Source.Length) < SA (Source.Length - 1)));
if I = 0 then
TA (1 .. J) := SA (1 .. Source.Length);
Source.Last := No_Index;
exit;
end if;
pragma Assert (I <= 1
or else not (TA (I) < TA (I - 1)));
if SA (Source.Length) < TA (I) then
TA (J) := TA (I);
I := I - 1;
else
TA (J) := SA (Source.Length);
Source.Last := Source.Last - 1;
end if;
J := J - 1;
end loop;
end;
end Merge;
----------
-- Sort --
----------
procedure Sort (Container : in out Vector) is
procedure Sort is
new Generic_Array_Sort
(Index_Type => Count_Type,
Element_Type => Element_Type,
Array_Type => Elements_Array,
"<" => "<");
begin
if Container.Last <= Index_Type'First then
return;
end if;
-- The exception behavior for the vector container must match that
-- for the list container, so we check for cursor tampering here
-- (which will catch more things) instead of for element tampering
-- (which will catch fewer things). It's true that the elements of
-- this vector container could be safely moved around while (say) an
-- iteration is taking place (iteration only increments the busy
-- counter), and so technically all we would need here is a test for
-- element tampering (indicated by the lock counter), that's simply
-- an artifact of our array-based implementation. Logically Sort
-- requires a check for cursor tampering.
TC_Check (Container.TC);
-- Per AI05-0022, the container implementation is required to detect
-- element tampering by a generic actual subprogram.
declare
Lock : With_Lock (Container.TC'Unchecked_Access);
begin
Sort (Container.Elements (1 .. Container.Length));
end;
end Sort;
end Generic_Sorting;
------------------------
-- Get_Element_Access --
------------------------
function Get_Element_Access
(Position : Cursor) return not null Element_Access is
begin
return Position.Container.Elements
(To_Array_Index (Position.Index))'Access;
end Get_Element_Access;
-----------------
-- Has_Element --
-----------------
function Has_Element (Position : Cursor) return Boolean is
begin
if Position.Container = null then
return False;
end if;
return Position.Index <= Position.Container.Last;
end Has_Element;
------------
-- Insert --
------------
procedure Insert
(Container : in out Vector;
Before : Extended_Index;
New_Item : Element_Type;
Count : Count_Type := 1)
is
EA : Elements_Array renames Container.Elements;
Old_Length : constant Count_Type := Container.Length;
Max_Length : Count_Type'Base; -- determined from range of Index_Type
New_Length : Count_Type'Base; -- sum of current length and Count
Index : Index_Type'Base; -- scratch for intermediate values
J : Count_Type'Base; -- scratch
begin
-- The tampering bits exist to prevent an item from being harmfully
-- manipulated while it is being visited. Query, Update, and Iterate
-- increment the busy count on entry, and decrement the count on
-- exit. Insert checks the count to determine whether it is being called
-- while the associated callback procedure is executing.
TC_Check (Container.TC);
-- As a precondition on the generic actual Index_Type, the base type
-- must include Index_Type'Pred (Index_Type'First); this is the value
-- that Container.Last assumes when the vector is empty. However, we do
-- not allow that as the value for Index when specifying where the new
-- items should be inserted, so we must manually check. (That the user
-- is allowed to specify the value at all here is a consequence of the
-- declaration of the Extended_Index subtype, which includes the values
-- in the base range that immediately precede and immediately follow the
-- values in the Index_Type.)
if Checks and then Before < Index_Type'First then
raise Constraint_Error with
"Before index is out of range (too small)";
end if;
-- We do allow a value greater than Container.Last to be specified as
-- the Index, but only if it's immediately greater. This allows for the
-- case of appending items to the back end of the vector. (It is assumed
-- that specifying an index value greater than Last + 1 indicates some
-- deeper flaw in the caller's algorithm, so that case is treated as a
-- proper error.)
if Checks and then Before > Container.Last
and then Before > Container.Last + 1
then
raise Constraint_Error with
"Before index is out of range (too large)";
end if;
-- We treat inserting 0 items into the container as a no-op, even when
-- the container is busy, so we simply return.
if Count = 0 then
return;
end if;
-- There are two constraints we need to satisfy. The first constraint is
-- that a container cannot have more than Count_Type'Last elements, so
-- we must check the sum of the current length and the insertion
-- count. Note that we cannot simply add these values, because of the
-- possibility of overflow.
if Checks and then Old_Length > Count_Type'Last - Count then
raise Constraint_Error with "Count is out of range";
end if;
-- It is now safe compute the length of the new vector, without fear of
-- overflow.
New_Length := Old_Length + Count;
-- The second constraint is that the new Last index value cannot exceed
-- Index_Type'Last. In each branch below, we calculate the maximum
-- length (computed from the range of values in Index_Type), and then
-- compare the new length to the maximum length. If the new length is
-- acceptable, then we compute the new last index from that.
if Index_Type'Base'Last >= Count_Type'Pos (Count_Type'Last) then
-- We have to handle the case when there might be more values in the
-- range of Index_Type than in the range of Count_Type.
if Index_Type'First <= 0 then
-- We know that No_Index (the same as Index_Type'First - 1) is
-- less than 0, so it is safe to compute the following sum without
-- fear of overflow.
Index := No_Index + Index_Type'Base (Count_Type'Last);
if Index <= Index_Type'Last then
-- We have determined that range of Index_Type has at least as
-- many values as in Count_Type, so Count_Type'Last is the
-- maximum number of items that are allowed.
Max_Length := Count_Type'Last;
else
-- The range of Index_Type has fewer values than in Count_Type,
-- so the maximum number of items is computed from the range of
-- the Index_Type.
Max_Length := Count_Type'Base (Index_Type'Last - No_Index);
end if;
else
-- No_Index is equal or greater than 0, so we can safely compute
-- the difference without fear of overflow (which we would have to
-- worry about if No_Index were less than 0, but that case is
-- handled above).
if Index_Type'Last - No_Index >=
Count_Type'Pos (Count_Type'Last)
then
-- We have determined that range of Index_Type has at least as
-- many values as in Count_Type, so Count_Type'Last is the
-- maximum number of items that are allowed.
Max_Length := Count_Type'Last;
else
-- The range of Index_Type has fewer values than in Count_Type,
-- so the maximum number of items is computed from the range of
-- the Index_Type.
Max_Length := Count_Type'Base (Index_Type'Last - No_Index);
end if;
end if;
elsif Index_Type'First <= 0 then
-- We know that No_Index (the same as Index_Type'First - 1) is less
-- than 0, so it is safe to compute the following sum without fear of
-- overflow.
J := Count_Type'Base (No_Index) + Count_Type'Last;
if J <= Count_Type'Base (Index_Type'Last) then
-- We have determined that range of Index_Type has at least as
-- many values as in Count_Type, so Count_Type'Last is the maximum
-- number of items that are allowed.
Max_Length := Count_Type'Last;
else
-- The range of Index_Type has fewer values than Count_Type does,
-- so the maximum number of items is computed from the range of
-- the Index_Type.
Max_Length :=
Count_Type'Base (Index_Type'Last) - Count_Type'Base (No_Index);
end if;
else
-- No_Index is equal or greater than 0, so we can safely compute the
-- difference without fear of overflow (which we would have to worry
-- about if No_Index were less than 0, but that case is handled
-- above).
Max_Length :=
Count_Type'Base (Index_Type'Last) - Count_Type'Base (No_Index);
end if;
-- We have just computed the maximum length (number of items). We must
-- now compare the requested length to the maximum length, as we do not
-- allow a vector expand beyond the maximum (because that would create
-- an internal array with a last index value greater than
-- Index_Type'Last, with no way to index those elements).
if Checks and then New_Length > Max_Length then
raise Constraint_Error with "Count is out of range";
end if;
if Checks and then New_Length > Container.Capacity then
raise Capacity_Error with "New length is larger than capacity";
end if;
J := To_Array_Index (Before);
if Before > Container.Last then
-- The new items are being appended to the vector, so no
-- sliding of existing elements is required.
EA (J .. New_Length) := (others => New_Item);
else
-- The new items are being inserted before some existing
-- elements, so we must slide the existing elements up to their
-- new home.
EA (J + Count .. New_Length) := EA (J .. Old_Length);
EA (J .. J + Count - 1) := (others => New_Item);
end if;
if Index_Type'Base'Last >= Count_Type'Pos (Count_Type'Last) then
Container.Last := No_Index + Index_Type'Base (New_Length);
else
Container.Last :=
Index_Type'Base (Count_Type'Base (No_Index) + New_Length);
end if;
end Insert;
procedure Insert_Vector
(Container : in out Vector;
Before : Extended_Index;
New_Item : Vector)
is
N : constant Count_Type := Length (New_Item);
B : Count_Type; -- index Before converted to Count_Type
begin
-- Use Insert_Space to create the "hole" (the destination slice) into
-- which we copy the source items.
Insert_Space (Container, Before, Count => N);
if N = 0 then
-- There's nothing else to do here (vetting of parameters was
-- performed already in Insert_Space), so we simply return.
return;
end if;
B := To_Array_Index (Before);
if Container'Address /= New_Item'Address then
-- This is the simple case. New_Item denotes an object different
-- from Container, so there's nothing special we need to do to copy
-- the source items to their destination, because all of the source
-- items are contiguous.
Container.Elements (B .. B + N - 1) := New_Item.Elements (1 .. N);
return;
end if;
-- We refer to array index value Before + N - 1 as J. This is the last
-- index value of the destination slice.
-- New_Item denotes the same object as Container, so an insertion has
-- potentially split the source items. The destination is always the
-- range [Before, J], but the source is [Index_Type'First, Before) and
-- (J, Container.Last]. We perform the copy in two steps, using each of
-- the two slices of the source items.
declare
subtype Src_Index_Subtype is Count_Type'Base range 1 .. B - 1;
Src : Elements_Array renames Container.Elements (Src_Index_Subtype);
begin
-- We first copy the source items that precede the space we
-- inserted. (If Before equals Index_Type'First, then this first
-- source slice will be empty, which is harmless.)
Container.Elements (B .. B + Src'Length - 1) := Src;
end;
declare
subtype Src_Index_Subtype is Count_Type'Base range
B + N .. Container.Length;
Src : Elements_Array renames Container.Elements (Src_Index_Subtype);
begin
-- We next copy the source items that follow the space we inserted.
Container.Elements (B + N - Src'Length .. B + N - 1) := Src;
end;
end Insert_Vector;
procedure Insert_Vector
(Container : in out Vector;
Before : Cursor;
New_Item : Vector)
is
Index : Index_Type'Base;
begin
if Checks and then Before.Container /= null
and then Before.Container /= Container'Unchecked_Access
then
raise Program_Error with "Before cursor denotes wrong container";
end if;
if Is_Empty (New_Item) then
return;
end if;
if Before.Container = null
or else Before.Index > Container.Last
then
if Checks and then Container.Last = Index_Type'Last then
raise Constraint_Error with
"vector is already at its maximum length";
end if;
Index := Container.Last + 1;
else
Index := Before.Index;
end if;
Insert_Vector (Container, Index, New_Item);
end Insert_Vector;
procedure Insert_Vector
(Container : in out Vector;
Before : Cursor;
New_Item : Vector;
Position : out Cursor)
is
Index : Index_Type'Base;
begin
if Checks and then Before.Container /= null
and then Before.Container /= Container'Unchecked_Access
then
raise Program_Error with "Before cursor denotes wrong container";
end if;
if Is_Empty (New_Item) then
if Before.Container = null
or else Before.Index > Container.Last
then
Position := No_Element;
else
Position := (Container'Unchecked_Access, Before.Index);
end if;
return;
end if;
if Before.Container = null
or else Before.Index > Container.Last
then
if Checks and then Container.Last = Index_Type'Last then
raise Constraint_Error with
"vector is already at its maximum length";
end if;
Index := Container.Last + 1;
else
Index := Before.Index;
end if;
Insert_Vector (Container, Index, New_Item);
Position := Cursor'(Container'Unchecked_Access, Index);
end Insert_Vector;
procedure Insert
(Container : in out Vector;
Before : Cursor;
New_Item : Element_Type;
Count : Count_Type := 1)
is
Index : Index_Type'Base;
begin
if Checks and then Before.Container /= null
and then Before.Container /= Container'Unchecked_Access
then
raise Program_Error with "Before cursor denotes wrong container";
end if;
if Count = 0 then
return;
end if;
if Before.Container = null
or else Before.Index > Container.Last
then
if Checks and then Container.Last = Index_Type'Last then
raise Constraint_Error with
"vector is already at its maximum length";
end if;
Index := Container.Last + 1;
else
Index := Before.Index;
end if;
Insert (Container, Index, New_Item, Count);
end Insert;
procedure Insert
(Container : in out Vector;
Before : Cursor;
New_Item : Element_Type;
Position : out Cursor;
Count : Count_Type := 1)
is
Index : Index_Type'Base;
begin
if Checks and then Before.Container /= null
and then Before.Container /= Container'Unchecked_Access
then
raise Program_Error with "Before cursor denotes wrong container";
end if;
if Count = 0 then
if Before.Container = null
or else Before.Index > Container.Last
then
Position := No_Element;
else
Position := (Container'Unchecked_Access, Before.Index);
end if;
return;
end if;
if Before.Container = null
or else Before.Index > Container.Last
then
if Checks and then Container.Last = Index_Type'Last then
raise Constraint_Error with
"vector is already at its maximum length";
end if;
Index := Container.Last + 1;
else
Index := Before.Index;
end if;
Insert (Container, Index, New_Item, Count);
Position := Cursor'(Container'Unchecked_Access, Index);
end Insert;
procedure Insert
(Container : in out Vector;
Before : Extended_Index;
Count : Count_Type := 1)
is
New_Item : Element_Type; -- Default-initialized value
pragma Warnings (Off, New_Item);
begin
Insert (Container, Before, New_Item, Count);
end Insert;
procedure Insert
(Container : in out Vector;
Before : Cursor;
Position : out Cursor;
Count : Count_Type := 1)
is
New_Item : Element_Type; -- Default-initialized value
pragma Warnings (Off, New_Item);
begin
Insert (Container, Before, New_Item, Position, Count);
end Insert;
------------------
-- Insert_Space --
------------------
procedure Insert_Space
(Container : in out Vector;
Before : Extended_Index;
Count : Count_Type := 1)
is
EA : Elements_Array renames Container.Elements;
Old_Length : constant Count_Type := Container.Length;
Max_Length : Count_Type'Base; -- determined from range of Index_Type
New_Length : Count_Type'Base; -- sum of current length and Count
Index : Index_Type'Base; -- scratch for intermediate values
J : Count_Type'Base; -- scratch
begin
-- The tampering bits exist to prevent an item from being harmfully
-- manipulated while it is being visited. Query, Update, and Iterate
-- increment the busy count on entry, and decrement the count on
-- exit. Insert checks the count to determine whether it is being called
-- while the associated callback procedure is executing.
TC_Check (Container.TC);
-- As a precondition on the generic actual Index_Type, the base type
-- must include Index_Type'Pred (Index_Type'First); this is the value
-- that Container.Last assumes when the vector is empty. However, we do
-- not allow that as the value for Index when specifying where the new
-- items should be inserted, so we must manually check. (That the user
-- is allowed to specify the value at all here is a consequence of the
-- declaration of the Extended_Index subtype, which includes the values
-- in the base range that immediately precede and immediately follow the
-- values in the Index_Type.)
if Checks and then Before < Index_Type'First then
raise Constraint_Error with
"Before index is out of range (too small)";
end if;
-- We do allow a value greater than Container.Last to be specified as
-- the Index, but only if it's immediately greater. This allows for the
-- case of appending items to the back end of the vector. (It is assumed
-- that specifying an index value greater than Last + 1 indicates some
-- deeper flaw in the caller's algorithm, so that case is treated as a
-- proper error.)
if Checks and then Before > Container.Last
and then Before > Container.Last + 1
then
raise Constraint_Error with
"Before index is out of range (too large)";
end if;
-- We treat inserting 0 items into the container as a no-op, even when
-- the container is busy, so we simply return.
if Count = 0 then
return;
end if;
-- There are two constraints we need to satisfy. The first constraint is
-- that a container cannot have more than Count_Type'Last elements, so
-- we must check the sum of the current length and the insertion count.
-- Note that we cannot simply add these values, because of the
-- possibility of overflow.
if Checks and then Old_Length > Count_Type'Last - Count then
raise Constraint_Error with "Count is out of range";
end if;
-- It is now safe compute the length of the new vector, without fear of
-- overflow.
New_Length := Old_Length + Count;
-- The second constraint is that the new Last index value cannot exceed
-- Index_Type'Last. In each branch below, we calculate the maximum
-- length (computed from the range of values in Index_Type), and then
-- compare the new length to the maximum length. If the new length is
-- acceptable, then we compute the new last index from that.
if Index_Type'Base'Last >= Count_Type'Pos (Count_Type'Last) then
-- We have to handle the case when there might be more values in the
-- range of Index_Type than in the range of Count_Type.
if Index_Type'First <= 0 then
-- We know that No_Index (the same as Index_Type'First - 1) is
-- less than 0, so it is safe to compute the following sum without
-- fear of overflow.
Index := No_Index + Index_Type'Base (Count_Type'Last);
if Index <= Index_Type'Last then
-- We have determined that range of Index_Type has at least as
-- many values as in Count_Type, so Count_Type'Last is the
-- maximum number of items that are allowed.
Max_Length := Count_Type'Last;
else
-- The range of Index_Type has fewer values than in Count_Type,
-- so the maximum number of items is computed from the range of
-- the Index_Type.
Max_Length := Count_Type'Base (Index_Type'Last - No_Index);
end if;
else
-- No_Index is equal or greater than 0, so we can safely compute
-- the difference without fear of overflow (which we would have to
-- worry about if No_Index were less than 0, but that case is
-- handled above).
if Index_Type'Last - No_Index >=
Count_Type'Pos (Count_Type'Last)
then
-- We have determined that range of Index_Type has at least as
-- many values as in Count_Type, so Count_Type'Last is the
-- maximum number of items that are allowed.
Max_Length := Count_Type'Last;
else
-- The range of Index_Type has fewer values than in Count_Type,
-- so the maximum number of items is computed from the range of
-- the Index_Type.
Max_Length := Count_Type'Base (Index_Type'Last - No_Index);
end if;
end if;
elsif Index_Type'First <= 0 then
-- We know that No_Index (the same as Index_Type'First - 1) is less
-- than 0, so it is safe to compute the following sum without fear of
-- overflow.
J := Count_Type'Base (No_Index) + Count_Type'Last;
if J <= Count_Type'Base (Index_Type'Last) then
-- We have determined that range of Index_Type has at least as
-- many values as in Count_Type, so Count_Type'Last is the maximum
-- number of items that are allowed.
Max_Length := Count_Type'Last;
else
-- The range of Index_Type has fewer values than Count_Type does,
-- so the maximum number of items is computed from the range of
-- the Index_Type.
Max_Length :=
Count_Type'Base (Index_Type'Last) - Count_Type'Base (No_Index);
end if;
else
-- No_Index is equal or greater than 0, so we can safely compute the
-- difference without fear of overflow (which we would have to worry
-- about if No_Index were less than 0, but that case is handled
-- above).
Max_Length :=
Count_Type'Base (Index_Type'Last) - Count_Type'Base (No_Index);
end if;
-- We have just computed the maximum length (number of items). We must
-- now compare the requested length to the maximum length, as we do not
-- allow a vector expand beyond the maximum (because that would create
-- an internal array with a last index value greater than
-- Index_Type'Last, with no way to index those elements).
if Checks and then New_Length > Max_Length then
raise Constraint_Error with "Count is out of range";
end if;
-- An internal array has already been allocated, so we need to check
-- whether there is enough unused storage for the new items.
if Checks and then New_Length > Container.Capacity then
raise Capacity_Error with "New length is larger than capacity";
end if;
-- In this case, we're inserting space into a vector that has already
-- allocated an internal array, and the existing array has enough
-- unused storage for the new items.
if Before <= Container.Last then
-- The space is being inserted before some existing elements,
-- so we must slide the existing elements up to their new home.
J := To_Array_Index (Before);
EA (J + Count .. New_Length) := EA (J .. Old_Length);
end if;
-- New_Last is the last index value of the items in the container after
-- insertion. Use the wider of Index_Type'Base and Count_Type'Base to
-- compute its value from the New_Length.
if Index_Type'Base'Last >= Count_Type'Pos (Count_Type'Last) then
Container.Last := No_Index + Index_Type'Base (New_Length);
else
Container.Last :=
Index_Type'Base (Count_Type'Base (No_Index) + New_Length);
end if;
end Insert_Space;
procedure Insert_Space
(Container : in out Vector;
Before : Cursor;
Position : out Cursor;
Count : Count_Type := 1)
is
Index : Index_Type'Base;
begin
if Checks and then Before.Container /= null
and then Before.Container /= Container'Unchecked_Access
then
raise Program_Error with "Before cursor denotes wrong container";
end if;
if Count = 0 then
if Before.Container = null
or else Before.Index > Container.Last
then
Position := No_Element;
else
Position := (Container'Unchecked_Access, Before.Index);
end if;
return;
end if;
if Before.Container = null
or else Before.Index > Container.Last
then
if Checks and then Container.Last = Index_Type'Last then
raise Constraint_Error with
"vector is already at its maximum length";
end if;
Index := Container.Last + 1;
else
Index := Before.Index;
end if;
Insert_Space (Container, Index, Count => Count);
Position := Cursor'(Container'Unchecked_Access, Index);
end Insert_Space;
--------------
-- Is_Empty --
--------------
function Is_Empty (Container : Vector) return Boolean is
begin
return Container.Last < Index_Type'First;
end Is_Empty;
-------------
-- Iterate --
-------------
procedure Iterate
(Container : Vector;
Process : not null access procedure (Position : Cursor))
is
Busy : With_Busy (Container.TC'Unrestricted_Access);
begin
for Indx in Index_Type'First .. Container.Last loop
Process (Cursor'(Container'Unrestricted_Access, Indx));
end loop;
end Iterate;
function Iterate
(Container : Vector)
return Vector_Iterator_Interfaces.Reversible_Iterator'Class
is
V : constant Vector_Access := Container'Unrestricted_Access;
begin
-- The value of its Index component influences the behavior of the First
-- and Last selector functions of the iterator object. When the Index
-- component is No_Index (as is the case here), this means the iterator
-- object was constructed without a start expression. This is a complete
-- iterator, meaning that the iteration starts from the (logical)
-- beginning of the sequence of items.
-- Note: For a forward iterator, Container.First is the beginning, and
-- for a reverse iterator, Container.Last is the beginning.
return It : constant Iterator :=
(Limited_Controlled with
Container => V,
Index => No_Index)
do
Busy (Container.TC'Unrestricted_Access.all);
end return;
end Iterate;
function Iterate
(Container : Vector;
Start : Cursor)
return Vector_Iterator_Interfaces.Reversible_Iterator'Class
is
V : constant Vector_Access := Container'Unrestricted_Access;
begin
-- It was formerly the case that when Start = No_Element, the partial
-- iterator was defined to behave the same as for a complete iterator,
-- and iterate over the entire sequence of items. However, those
-- semantics were unintuitive and arguably error-prone (it is too easy
-- to accidentally create an endless loop), and so they were changed,
-- per the ARG meeting in Denver on 2011/11. However, there was no
-- consensus about what positive meaning this corner case should have,
-- and so it was decided to simply raise an exception. This does imply,
-- however, that it is not possible to use a partial iterator to specify
-- an empty sequence of items.
if Checks and then Start.Container = null then
raise Constraint_Error with
"Start position for iterator equals No_Element";
end if;
if Checks and then Start.Container /= V then
raise Program_Error with
"Start cursor of Iterate designates wrong vector";
end if;
if Checks and then Start.Index > V.Last then
raise Constraint_Error with
"Start position for iterator equals No_Element";
end if;
-- The value of its Index component influences the behavior of the First
-- and Last selector functions of the iterator object. When the Index
-- component is not No_Index (as is the case here), it means that this
-- is a partial iteration, over a subset of the complete sequence of
-- items. The iterator object was constructed with a start expression,
-- indicating the position from which the iteration begins. Note that
-- the start position has the same value irrespective of whether this is
-- a forward or reverse iteration.
return It : constant Iterator :=
(Limited_Controlled with
Container => V,
Index => Start.Index)
do
Busy (Container.TC'Unrestricted_Access.all);
end return;
end Iterate;
----------
-- Last --
----------
function Last (Container : Vector) return Cursor is
begin
if Is_Empty (Container) then
return No_Element;
else
return (Container'Unrestricted_Access, Container.Last);
end if;
end Last;
function Last (Object : Iterator) return Cursor is
begin
-- The value of the iterator object's Index component influences the
-- behavior of the Last (and First) selector function.
-- When the Index component is No_Index, this means the iterator object
-- was constructed without a start expression, in which case the
-- (reverse) iteration starts from the (logical) beginning of the entire
-- sequence (corresponding to Container.Last, for a reverse iterator).
-- Otherwise, this is iteration over a partial sequence of items. When
-- the Index component is not No_Index, the iterator object was
-- constructed with a start expression, that specifies the position from
-- which the (reverse) partial iteration begins.
if Object.Index = No_Index then
return Last (Object.Container.all);
else
return Cursor'(Object.Container, Object.Index);
end if;
end Last;
------------------
-- Last_Element --
------------------
function Last_Element (Container : Vector) return Element_Type is
begin
if Checks and then Container.Last = No_Index then
raise Constraint_Error with "Container is empty";
end if;
return Container.Elements (Container.Length);
end Last_Element;
----------------
-- Last_Index --
----------------
function Last_Index (Container : Vector) return Extended_Index is
begin
return Container.Last;
end Last_Index;
------------
-- Length --
------------
function Length (Container : Vector) return Count_Type is
L : constant Index_Type'Base := Container.Last;
F : constant Index_Type := Index_Type'First;
begin
-- The base range of the index type (Index_Type'Base) might not include
-- all values for length (Count_Type). Contrariwise, the index type
-- might include values outside the range of length. Hence we use
-- whatever type is wider for intermediate values when calculating
-- length. Note that no matter what the index type is, the maximum
-- length to which a vector is allowed to grow is always the minimum
-- of Count_Type'Last and (IT'Last - IT'First + 1).
-- For example, an Index_Type with range -127 .. 127 is only guaranteed
-- to have a base range of -128 .. 127, but the corresponding vector
-- would have lengths in the range 0 .. 255. In this case we would need
-- to use Count_Type'Base for intermediate values.
-- Another case would be the index range -2**63 + 1 .. -2**63 + 10. The
-- vector would have a maximum length of 10, but the index values lie
-- outside the range of Count_Type (which is only 32 bits). In this
-- case we would need to use Index_Type'Base for intermediate values.
if Count_Type'Base'Last >= Index_Type'Pos (Index_Type'Base'Last) then
return Count_Type'Base (L) - Count_Type'Base (F) + 1;
else
return Count_Type (L - F + 1);
end if;
end Length;
----------
-- Move --
----------
procedure Move
(Target : in out Vector;
Source : in out Vector)
is
begin
if Target'Address = Source'Address then
return;
end if;
TC_Check (Target.TC);
TC_Check (Source.TC);
if Checks and then Target.Capacity < Source.Length then
raise Capacity_Error -- ???
with "Target capacity is less than Source length";
end if;
-- Clear Target now, in case element assignment fails
Target.Last := No_Index;
Target.Elements (1 .. Source.Length) :=
Source.Elements (1 .. Source.Length);
Target.Last := Source.Last;
Source.Last := No_Index;
end Move;
----------
-- Next --
----------
function Next (Position : Cursor) return Cursor is
begin
if Position.Container = null then
return No_Element;
elsif Position.Index < Position.Container.Last then
return (Position.Container, Position.Index + 1);
else
return No_Element;
end if;
end Next;
function Next (Object : Iterator; Position : Cursor) return Cursor is
begin
if Position.Container = null then
return No_Element;
end if;
if Checks and then Position.Container /= Object.Container then
raise Program_Error with
"Position cursor of Next designates wrong vector";
end if;
return Next (Position);
end Next;
procedure Next (Position : in out Cursor) is
begin
if Position.Container = null then
return;
elsif Position.Index < Position.Container.Last then
Position.Index := Position.Index + 1;
else
Position := No_Element;
end if;
end Next;
-------------
-- Prepend --
-------------
procedure Prepend
(Container : in out Vector;
New_Item : Element_Type;
Count : Count_Type := 1)
is
begin
Insert (Container, Index_Type'First, New_Item, Count);
end Prepend;
--------------------
-- Prepend_Vector --
--------------------
procedure Prepend_Vector (Container : in out Vector; New_Item : Vector) is
begin
Insert_Vector (Container, Index_Type'First, New_Item);
end Prepend_Vector;
--------------
-- Previous --
--------------
procedure Previous (Position : in out Cursor) is
begin
if Position.Container = null then
return;
elsif Position.Index > Index_Type'First then
Position.Index := Position.Index - 1;
else
Position := No_Element;
end if;
end Previous;
function Previous (Position : Cursor) return Cursor is
begin
if Position.Container = null then
return No_Element;
elsif Position.Index > Index_Type'First then
return (Position.Container, Position.Index - 1);
else
return No_Element;
end if;
end Previous;
function Previous (Object : Iterator; Position : Cursor) return Cursor is
begin
if Position.Container = null then
return No_Element;
end if;
if Checks and then Position.Container /= Object.Container then
raise Program_Error with
"Position cursor of Previous designates wrong vector";
end if;
return Previous (Position);
end Previous;
----------------------
-- Pseudo_Reference --
----------------------
function Pseudo_Reference
(Container : aliased Vector'Class) return Reference_Control_Type
is
TC : constant Tamper_Counts_Access := Container.TC'Unrestricted_Access;
begin
return R : constant Reference_Control_Type := (Controlled with TC) do
Busy (TC.all);
end return;
end Pseudo_Reference;
-------------------
-- Query_Element --
-------------------
procedure Query_Element
(Container : Vector;
Index : Index_Type;
Process : not null access procedure (Element : Element_Type))
is
Lock : With_Lock (Container.TC'Unrestricted_Access);
V : Vector renames Container'Unrestricted_Access.all;
begin
if Checks and then Index > Container.Last then
raise Constraint_Error with "Index is out of range";
end if;
Process (V.Elements (To_Array_Index (Index)));
end Query_Element;
procedure Query_Element
(Position : Cursor;
Process : not null access procedure (Element : Element_Type))
is
begin
if Checks and then Position.Container = null then
raise Constraint_Error with "Position cursor has no element";
end if;
Query_Element (Position.Container.all, Position.Index, Process);
end Query_Element;
---------------
-- Put_Image --
---------------
procedure Put_Image
(S : in out Ada.Strings.Text_Buffers.Root_Buffer_Type'Class; V : Vector)
is
First_Time : Boolean := True;
use System.Put_Images;
begin
Array_Before (S);
for X of V loop
if First_Time then
First_Time := False;
else
Simple_Array_Between (S);
end if;
Element_Type'Put_Image (S, X);
end loop;
Array_After (S);
end Put_Image;
----------
-- Read --
----------
procedure Read
(Stream : not null access Root_Stream_Type'Class;
Container : out Vector)
is
Length : Count_Type'Base;
Last : Index_Type'Base := No_Index;
begin
Clear (Container);
Count_Type'Base'Read (Stream, Length);
Reserve_Capacity (Container, Capacity => Length);
for Idx in Count_Type range 1 .. Length loop
Last := Last + 1;
Element_Type'Read (Stream, Container.Elements (Idx));
Container.Last := Last;
end loop;
end Read;
procedure Read
(Stream : not null access Root_Stream_Type'Class;
Position : out Cursor)
is
begin
raise Program_Error with "attempt to stream vector cursor";
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 Vector;
Position : Cursor) return Reference_Type
is
begin
if Checks and then Position.Container = null then
raise Constraint_Error with "Position cursor has no element";
end if;
if Checks and then Position.Container /= Container'Unrestricted_Access
then
raise Program_Error with "Position cursor denotes wrong container";
end if;
if Checks and then Position.Index > Position.Container.Last then
raise Constraint_Error with "Position cursor is out of range";
end if;
declare
A : Elements_Array renames Container.Elements;
J : constant Count_Type := To_Array_Index (Position.Index);
TC : constant Tamper_Counts_Access :=
Container.TC'Unrestricted_Access;
begin
return R : constant Reference_Type :=
(Element => A (J)'Unchecked_Access,
Control => (Controlled with TC))
do
Busy (TC.all);
end return;
end;
end Reference;
function Reference
(Container : aliased in out Vector;
Index : Index_Type) return Reference_Type
is
begin
if Checks and then Index > Container.Last then
raise Constraint_Error with "Index is out of range";
end if;
declare
A : Elements_Array renames Container.Elements;
J : constant Count_Type := To_Array_Index (Index);
TC : constant Tamper_Counts_Access :=
Container.TC'Unrestricted_Access;
begin
return R : constant Reference_Type :=
(Element => A (J)'Unchecked_Access,
Control => (Controlled with TC))
do
Busy (TC.all);
end return;
end;
end Reference;
---------------------
-- Replace_Element --
---------------------
procedure Replace_Element
(Container : in out Vector;
Index : Index_Type;
New_Item : Element_Type)
is
begin
TE_Check (Container.TC);
if Checks and then Index > Container.Last then
raise Constraint_Error with "Index is out of range";
end if;
Container.Elements (To_Array_Index (Index)) := New_Item;
end Replace_Element;
procedure Replace_Element
(Container : in out Vector;
Position : Cursor;
New_Item : Element_Type)
is
begin
TE_Check (Container.TC);
if Checks and then Position.Container = null then
raise Constraint_Error with "Position cursor has no element";
end if;
if Checks and then Position.Container /= Container'Unrestricted_Access
then
raise Program_Error with "Position cursor denotes wrong container";
end if;
if Checks and then Position.Index > Container.Last then
raise Constraint_Error with "Position cursor is out of range";
end if;
Container.Elements (To_Array_Index (Position.Index)) := New_Item;
end Replace_Element;
----------------------
-- Reserve_Capacity --
----------------------
procedure Reserve_Capacity
(Container : in out Vector;
Capacity : Count_Type)
is
begin
if Checks and then Capacity > Container.Capacity then
raise Capacity_Error with "Capacity is out of range";
end if;
end Reserve_Capacity;
----------------------
-- Reverse_Elements --
----------------------
procedure Reverse_Elements (Container : in out Vector) is
E : Elements_Array renames Container.Elements;
Idx : Count_Type;
Jdx : Count_Type;
begin
if Container.Length <= 1 then
return;
end if;
-- The exception behavior for the vector container must match that for
-- the list container, so we check for cursor tampering here (which will
-- catch more things) instead of for element tampering (which will catch
-- fewer things). It's true that the elements of this vector container
-- could be safely moved around while (say) an iteration is taking place
-- (iteration only increments the busy counter), and so technically
-- all we would need here is a test for element tampering (indicated
-- by the lock counter), that's simply an artifact of our array-based
-- implementation. Logically Reverse_Elements requires a check for
-- cursor tampering.
TC_Check (Container.TC);
Idx := 1;
Jdx := Container.Length;
while Idx < Jdx loop
declare
EI : constant Element_Type := E (Idx);
begin
E (Idx) := E (Jdx);
E (Jdx) := EI;
end;
Idx := Idx + 1;
Jdx := Jdx - 1;
end loop;
end Reverse_Elements;
------------------
-- Reverse_Find --
------------------
function Reverse_Find
(Container : Vector;
Item : Element_Type;
Position : Cursor := No_Element) return Cursor
is
Last : Index_Type'Base;
begin
if Checks and then Position.Container /= null
and then Position.Container /= Container'Unrestricted_Access
then
raise Program_Error with "Position cursor denotes wrong container";
end if;
Last :=
(if Position.Container = null or else Position.Index > Container.Last
then Container.Last
else Position.Index);
-- Per AI05-0022, the container implementation is required to detect
-- element tampering by a generic actual subprogram.
declare
Lock : With_Lock (Container.TC'Unrestricted_Access);
begin
for Indx in reverse Index_Type'First .. Last loop
if Container.Elements (To_Array_Index (Indx)) = Item then
return Cursor'(Container'Unrestricted_Access, Indx);
end if;
end loop;
return No_Element;
end;
end Reverse_Find;
------------------------
-- Reverse_Find_Index --
------------------------
function Reverse_Find_Index
(Container : Vector;
Item : Element_Type;
Index : Index_Type := Index_Type'Last) return Extended_Index
is
-- Per AI05-0022, the container implementation is required to detect
-- element tampering by a generic actual subprogram.
Lock : With_Lock (Container.TC'Unrestricted_Access);
Last : constant Index_Type'Base :=
Index_Type'Min (Container.Last, Index);
begin
for Indx in reverse Index_Type'First .. Last loop
if Container.Elements (To_Array_Index (Indx)) = Item then
return Indx;
end if;
end loop;
return No_Index;
end Reverse_Find_Index;
---------------------
-- Reverse_Iterate --
---------------------
procedure Reverse_Iterate
(Container : Vector;
Process : not null access procedure (Position : Cursor))
is
Busy : With_Busy (Container.TC'Unrestricted_Access);
begin
for Indx in reverse Index_Type'First .. Container.Last loop
Process (Cursor'(Container'Unrestricted_Access, Indx));
end loop;
end Reverse_Iterate;
----------------
-- Set_Length --
----------------
procedure Set_Length (Container : in out Vector; Length : Count_Type) is
Count : constant Count_Type'Base := Container.Length - Length;
begin
-- Set_Length allows the user to set the length explicitly, instead of
-- implicitly as a side-effect of deletion or insertion. If the
-- requested length is less than the current length, this is equivalent
-- to deleting items from the back end of the vector. If the requested
-- length is greater than the current length, then this is equivalent to
-- inserting "space" (nonce items) at the end.
if Count >= 0 then
Container.Delete_Last (Count);
elsif Checks and then Container.Last >= Index_Type'Last then
raise Constraint_Error with "vector is already at its maximum length";
else
Container.Insert_Space (Container.Last + 1, -Count);
end if;
end Set_Length;
----------
-- Swap --
----------
procedure Swap (Container : in out Vector; I, J : Index_Type) is
E : Elements_Array renames Container.Elements;
begin
TE_Check (Container.TC);
if Checks and then I > Container.Last then
raise Constraint_Error with "I index is out of range";
end if;
if Checks and then J > Container.Last then
raise Constraint_Error with "J index is out of range";
end if;
if I = J then
return;
end if;
declare
EI_Copy : constant Element_Type := E (To_Array_Index (I));
begin
E (To_Array_Index (I)) := E (To_Array_Index (J));
E (To_Array_Index (J)) := EI_Copy;
end;
end Swap;
procedure Swap (Container : in out Vector; I, J : Cursor) is
begin
if Checks and then I.Container = null then
raise Constraint_Error with "I cursor has no element";
end if;
if Checks and then J.Container = null then
raise Constraint_Error with "J cursor has no element";
end if;
if Checks and then I.Container /= Container'Unrestricted_Access then
raise Program_Error with "I cursor denotes wrong container";
end if;
if Checks and then J.Container /= Container'Unrestricted_Access then
raise Program_Error with "J cursor denotes wrong container";
end if;
Swap (Container, I.Index, J.Index);
end Swap;
--------------------
-- To_Array_Index --
--------------------
function To_Array_Index (Index : Index_Type'Base) return Count_Type'Base is
Offset : Count_Type'Base;
begin
-- We know that
-- Index >= Index_Type'First
-- hence we also know that
-- Index - Index_Type'First >= 0
-- The issue is that even though 0 is guaranteed to be a value in
-- the type Index_Type'Base, there's no guarantee that the difference
-- is a value in that type. To prevent overflow we use the wider
-- of Count_Type'Base and Index_Type'Base to perform intermediate
-- calculations.
if Index_Type'Base'Last >= Count_Type'Pos (Count_Type'Last) then
Offset := Count_Type'Base (Index - Index_Type'First);
else
Offset := Count_Type'Base (Index) -
Count_Type'Base (Index_Type'First);
end if;
-- The array index subtype for all container element arrays
-- always starts with 1.
return 1 + Offset;
end To_Array_Index;
---------------
-- To_Cursor --
---------------
function To_Cursor
(Container : Vector;
Index : Extended_Index) return Cursor
is
begin
if Index not in Index_Type'First .. Container.Last then
return No_Element;
end if;
return Cursor'(Container'Unrestricted_Access, Index);
end To_Cursor;
--------------
-- To_Index --
--------------
function To_Index (Position : Cursor) return Extended_Index is
begin
if Position.Container = null then
return No_Index;
end if;
if Position.Index <= Position.Container.Last then
return Position.Index;
end if;
return No_Index;
end To_Index;
---------------
-- To_Vector --
---------------
function To_Vector (Length : Count_Type) return Vector is
Index : Count_Type'Base;
Last : Index_Type'Base;
begin
if Length = 0 then
return Empty_Vector;
end if;
-- We create a vector object with a capacity that matches the specified
-- Length, but we do not allow the vector capacity (the length of the
-- internal array) to exceed the number of values in Index_Type'Range
-- (otherwise, there would be no way to refer to those components via an
-- index). We must therefore check whether the specified Length would
-- create a Last index value greater than Index_Type'Last.
if Index_Type'Base'Last >= Count_Type'Pos (Count_Type'Last) then
-- We perform a two-part test. First we determine whether the
-- computed Last value lies in the base range of the type, and then
-- determine whether it lies in the range of the index (sub)type.
-- Last must satisfy this relation:
-- First + Length - 1 <= Last
-- We regroup terms:
-- First - 1 <= Last - Length
-- Which can rewrite as:
-- No_Index <= Last - Length
if Checks and then
Index_Type'Base'Last - Index_Type'Base (Length) < No_Index
then
raise Constraint_Error with "Length is out of range";
end if;
-- We now know that the computed value of Last is within the base
-- range of the type, so it is safe to compute its value:
Last := No_Index + Index_Type'Base (Length);
-- Finally we test whether the value is within the range of the
-- generic actual index subtype:
if Checks and then Last > Index_Type'Last then
raise Constraint_Error with "Length is out of range";
end if;
elsif Index_Type'First <= 0 then
-- Here we can compute Last directly, in the normal way. We know that
-- No_Index is less than 0, so there is no danger of overflow when
-- adding the (positive) value of Length.
Index := Count_Type'Base (No_Index) + Length; -- Last
if Checks and then Index > Count_Type'Base (Index_Type'Last) then
raise Constraint_Error with "Length is out of range";
end if;
-- We know that the computed value (having type Count_Type) of Last
-- is within the range of the generic actual index subtype, so it is
-- safe to convert to Index_Type:
Last := Index_Type'Base (Index);
else
-- Here Index_Type'First (and Index_Type'Last) is positive, so we
-- must test the length indirectly (by working backwards from the
-- largest possible value of Last), in order to prevent overflow.
Index := Count_Type'Base (Index_Type'Last) - Length; -- No_Index
if Checks and then Index < Count_Type'Base (No_Index) then
raise Constraint_Error with "Length is out of range";
end if;
-- We have determined that the value of Length would not create a
-- Last index value outside of the range of Index_Type, so we can now
-- safely compute its value.
Last := Index_Type'Base (Count_Type'Base (No_Index) + Length);
end if;
return V : Vector (Capacity => Length) do
V.Last := Last;
end return;
end To_Vector;
function To_Vector
(New_Item : Element_Type;
Length : Count_Type) return Vector
is
Index : Count_Type'Base;
Last : Index_Type'Base;
begin
if Length = 0 then
return Empty_Vector;
end if;
-- We create a vector object with a capacity that matches the specified
-- Length, but we do not allow the vector capacity (the length of the
-- internal array) to exceed the number of values in Index_Type'Range
-- (otherwise, there would be no way to refer to those components via an
-- index). We must therefore check whether the specified Length would
-- create a Last index value greater than Index_Type'Last.
if Index_Type'Base'Last >= Count_Type'Pos (Count_Type'Last) then
-- We perform a two-part test. First we determine whether the
-- computed Last value lies in the base range of the type, and then
-- determine whether it lies in the range of the index (sub)type.
-- Last must satisfy this relation:
-- First + Length - 1 <= Last
-- We regroup terms:
-- First - 1 <= Last - Length
-- Which can rewrite as:
-- No_Index <= Last - Length
if Checks and then
Index_Type'Base'Last - Index_Type'Base (Length) < No_Index
then
raise Constraint_Error with "Length is out of range";
end if;
-- We now know that the computed value of Last is within the base
-- range of the type, so it is safe to compute its value:
Last := No_Index + Index_Type'Base (Length);
-- Finally we test whether the value is within the range of the
-- generic actual index subtype:
if Checks and then Last > Index_Type'Last then
raise Constraint_Error with "Length is out of range";
end if;
elsif Index_Type'First <= 0 then
-- Here we can compute Last directly, in the normal way. We know that
-- No_Index is less than 0, so there is no danger of overflow when
-- adding the (positive) value of Length.
Index := Count_Type'Base (No_Index) + Length; -- same value as V.Last
if Checks and then Index > Count_Type'Base (Index_Type'Last) then
raise Constraint_Error with "Length is out of range";
end if;
-- We know that the computed value (having type Count_Type) of Last
-- is within the range of the generic actual index subtype, so it is
-- safe to convert to Index_Type:
Last := Index_Type'Base (Index);
else
-- Here Index_Type'First (and Index_Type'Last) is positive, so we
-- must test the length indirectly (by working backwards from the
-- largest possible value of Last), in order to prevent overflow.
Index := Count_Type'Base (Index_Type'Last) - Length; -- No_Index
if Checks and then Index < Count_Type'Base (No_Index) then
raise Constraint_Error with "Length is out of range";
end if;
-- We have determined that the value of Length would not create a
-- Last index value outside of the range of Index_Type, so we can now
-- safely compute its value.
Last := Index_Type'Base (Count_Type'Base (No_Index) + Length);
end if;
return V : Vector (Capacity => Length) do
V.Elements := (others => New_Item);
V.Last := Last;
end return;
end To_Vector;
--------------------
-- Update_Element --
--------------------
procedure Update_Element
(Container : in out Vector;
Index : Index_Type;
Process : not null access procedure (Element : in out Element_Type))
is
Lock : With_Lock (Container.TC'Unchecked_Access);
begin
if Checks and then Index > Container.Last then
raise Constraint_Error with "Index is out of range";
end if;
Process (Container.Elements (To_Array_Index (Index)));
end Update_Element;
procedure Update_Element
(Container : in out Vector;
Position : Cursor;
Process : not null access procedure (Element : in out Element_Type))
is
begin
if Checks and then Position.Container = null then
raise Constraint_Error with "Position cursor has no element";
end if;
if Checks and then Position.Container /= Container'Unrestricted_Access
then
raise Program_Error with "Position cursor denotes wrong container";
end if;
Update_Element (Container, Position.Index, Process);
end Update_Element;
-----------
-- Write --
-----------
procedure Write
(Stream : not null access Root_Stream_Type'Class;
Container : Vector)
is
N : Count_Type;
begin
N := Container.Length;
Count_Type'Base'Write (Stream, N);
for J in 1 .. N loop
Element_Type'Write (Stream, Container.Elements (J));
end loop;
end Write;
procedure Write
(Stream : not null access Root_Stream_Type'Class;
Position : Cursor)
is
begin
raise Program_Error with "attempt to stream vector cursor";
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.Bounded_Vectors;