A.18.2 The Generic Package Containers.Vectors
The language-defined generic package Containers.Vectors
provides private types Vector and Cursor, and a set of operations for
each type. A vector container allows insertion and deletion at any position,
but it is specifically optimized for insertion and deletion at the high
end (the end with the higher index) of the container. A vector container
also provides random access to its elements.
A vector
container behaves conceptually as an array that expands as necessary
as items are inserted. The
length of a vector is the number of
elements that the vector contains. The
capacity of a vector is
the maximum number of elements that can be inserted into the vector prior
to it being automatically expanded.
Elements in a vector container can be referred to
by an index value of a generic formal type. The first element of a vector
always has its index value equal to the lower bound of the formal type.
A vector container may contain
empty elements. Empty elements do not have a specified value.
Static Semantics
The generic library
package Containers.Vectors has the following declaration:
with Ada.Iterator_Interfaces;
generic
type Index_Type
is range <>;
type Element_Type
is private;
with function "=" (Left, Right : Element_Type)
return Boolean
is <>;
package Ada.Containers.Vectors
with Preelaborate, Remote_Types,
Nonblocking, Global =>
in out synchronized is
subtype Extended_Index
is
Index_Type'Base
range
Index_Type'First-1 ..
Index_Type'Min (Index_Type'Base'Last - 1, Index_Type'Last) + 1;
No_Index :
constant Extended_Index := Extended_Index'First;
type Vector
is tagged private
with Constant_Indexing => Constant_Reference,
Variable_Indexing => Reference,
Default_Iterator => Iterate,
Iterator_Element => Element_Type,
Iterator_View => Stable.Vector,
Aggregate => (Empty => Empty,
Add_Unnamed => Append,
New_Indexed => New_Vector,
Assign_Indexed => Replace_Element),
Stable_Properties => (Length, Capacity,
Tampering_With_Cursors_Prohibited,
Tampering_With_Elements_Prohibited),
Default_Initial_Condition =>
Length (Vector) = 0
and then
(
not Tampering_With_Cursors_Prohibited (Vector))
and then
(
not Tampering_With_Elements_Prohibited (Vector)),
Preelaborable_Initialization;
type Cursor
is private
with Preelaborable_Initialization;
Empty_Vector :
constant Vector;
No_Element :
constant Cursor;
function Has_Element (Position : Cursor)
return Boolean
with Nonblocking, Global =>
in all, Use_Formal =>
null;
function Has_Element (Container : Vector; Position : Cursor)
return Boolean
with Nonblocking, Global =>
null, Use_Formal =>
null;
package Vector_Iterator_Interfaces
is new
Ada.Iterator_Interfaces (Cursor, Has_Element);
function "=" (Left, Right : Vector) return Boolean;
function Tampering_With_Cursors_Prohibited
(Container : Vector)
return Boolean
with Nonblocking, Global =>
null, Use_Formal =>
null;
function Tampering_With_Elements_Prohibited
(Container : Vector)
return Boolean
with Nonblocking, Global =>
null, Use_Formal =>
null;
function Maximum_Length
return Count_Type
with Nonblocking, Global =>
null, Use_Formal =>
null;
function Empty (Capacity : Count_Type :=
implementation-defined)
return Vector
with Pre => Capacity <= Maximum_Length
or else raise Constraint_Error,
Post =>
Capacity (Empty'Result) >= Capacity
and then
not Tampering_With_Elements_Prohibited (Empty'Result)
and then
not Tampering_With_Cursors_Prohibited (Empty'Result)
and then
Length (Empty'Result) = 0;
function To_Vector (Length : Count_Type)
return Vector
with Pre => Length <= Maximum_Length
or else raise Constraint_Error,
Post =>
To_Vector'Result.Length = Length
and then
not Tampering_With_Elements_Prohibited (To_Vector'Result)
and then
not Tampering_With_Cursors_Prohibited (To_Vector'Result)
and then
To_Vector'Result.Capacity >= Length;
function To_Vector
(New_Item : Element_Type;
Length : Count_Type)
return Vector
with Pre => Length <= Maximum_Length
or else raise Constraint_Error,
Post =>
To_Vector'Result.Length = Length
and then
not Tampering_With_Elements_Prohibited (To_Vector'Result)
and then
not Tampering_With_Cursors_Prohibited (To_Vector'Result)
and then
To_Vector'Result.Capacity >= Length;
function New_Vector (First, Last : Index_Type)
return Vector
is
(To_Vector (Count_Type (Last - First + 1)))
with Pre => First = Index_Type'First;
function "&" (Left, Right : Vector) return Vector
with Pre => Length (Left) <= Maximum_Length - Length (Right)
or else raise Constraint_Error,
Post => Length (Vectors."&"'Result) =
Length (Left) + Length (Right) and then
not Tampering_With_Elements_Prohibited
(Vectors."&"'Result) and then
not Tampering_With_Cursors_Prohibited
(Vectors."&"'Result) and then
Vectors."&"'Result.Capacity >=
Length (Left) + Length (Right);
function "&" (Left : Vector;
Right : Element_Type) return Vector
with Pre => Length (Left) <= Maximum_Length - 1
or else raise Constraint_Error,
Post => Vectors."&"'Result.Length = Length (Left) + 1 and then
not Tampering_With_Elements_Prohibited
(Vectors."&"'Result) and then
not Tampering_With_Cursors_Prohibited
(Vectors."&"'Result) and then
Vectors."&"'Result.Capacity >= Length (Left) + 1;
function "&" (Left : Element_Type;
Right : Vector) return Vector
with Pre => Length (Right) <= Maximum_Length - 1
or else raise Constraint_Error,
Post => Length (Vectors."&"'Result) = Length (Right) + 1 and then
not Tampering_With_Elements_Prohibited
(Vectors."&"'Result) and then
not Tampering_With_Cursors_Prohibited
(Vectors."&"'Result) and then
Vectors."&"'Result.Capacity >= Length (Right) + 1;
function "&" (Left, Right : Element_Type) return Vector
with Pre => Maximum_Length >= 2 or else raise Constraint_Error,
Post => Length ("&"'Result) = 2 and then
not Tampering_With_Elements_Prohibited
(Vectors."&"'Result) and then
not Tampering_With_Cursors_Prohibited
(Vectors."&"'Result) and then
Vectors."&"'Result.Capacity >= 2;
function Capacity (Container : Vector)
return Count_Type
with Nonblocking, Global =>
null, Use_Formal =>
null;
procedure Reserve_Capacity (Container :
in out Vector;
Capacity :
in Count_Type)
with Pre =>
not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error,
Post => Container.Capacity >= Capacity;
function Length (Container : Vector)
return Count_Type
with Nonblocking, Global =>
null, Use_Formal =>
null;
procedure Set_Length (Container :
in out Vector;
Length :
in Count_Type)
with Pre => (
not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error)
and then
(Length <= Maximum_Length
or else raise Constraint_Error),
Post => Container.Length = Length
and then
Capacity (Container) >= Length;
function Is_Empty (Container : Vector)
return Boolean
with Nonblocking, Global =>
null, Use_Formal =>
null,
Post => Is_Empty'Result = (Length (Container) = 0);
procedure Clear (Container :
in out Vector)
with Pre =>
not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error,
Post => Length (Container) = 0;
function To_Cursor (Container : Vector;
Index : Extended_Index)
return Cursor
with Post => (
if Index
in
First_Index (Container) .. Last_Index (Container)
then Has_Element (Container, To_Cursor'Result)
else To_Cursor'Result = No_Element),
Nonblocking, Global =>
null, Use_Formal =>
null;
function To_Index (Position : Cursor)
return Extended_Index
with Nonblocking, Global =>
in all;
function To_Index (Container : Vector;
Position : Cursor)
return Extended_Index
with Pre => Position = No_Element
or else
Has_Element (Container, Position)
or else
raise Program_Error,
Post => (
if Position = No_Element
then To_Index'Result = No_Index
else To_Index'Result
in First_Index (Container) ..
Last_Index (Container)),
Nonblocking, Global =>
null, Use_Formal =>
null;
function Element (Container : Vector;
Index : Index_Type)
return Element_Type
with Pre => Index
in
First_Index (Container) .. Last_Index (Container)
or else raise Constraint_Error,
Nonblocking, Global =>
null, Use_Formal => Element_Type;
function Element (Position : Cursor)
return Element_Type
with Pre => Position /= No_Element
or else raise Constraint_Error,
Nonblocking, Global =>
in all, Use_Formal => Element_Type;
function Element (Container : Vector;
Position : Cursor)
return Element_Type
with Pre => (Position /= No_Element
or else
raise Constraint_Error)
and then
(Has_Element (Container, Position)
or else raise Program_Error),
Nonblocking, Global =>
null, Use_Formal => Element_Type;
procedure Replace_Element (Container :
in out Vector;
Index :
in Index_Type;
New_Item :
in Element_Type)
with Pre => (
not Tampering_With_Elements_Prohibited (Container)
or else raise Program_Error)
and then
(Index
in
First_Index (Container) .. Last_Index (Container)
or else raise Constraint_Error);
procedure Replace_Element (Container :
in out Vector;
Position :
in Cursor;
New_item :
in Element_Type)
with Pre => (
not Tampering_With_Elements_Prohibited (Container)
or else raise Program_Error)
and then
(Position /= No_Element
or else raise Constraint_Error)
and then
(Has_Element (Container, Position)
or else raise Program_Error);
procedure Query_Element
(Container :
in Vector;
Index :
in Index_Type;
Process :
not null access procedure (Element :
in Element_Type))
with Pre => Index
in
First_Index (Container) .. Last_Index (Container)
or else raise Constraint_Error;
procedure Query_Element
(Position :
in Cursor;
Process :
not null access procedure (Element :
in Element_Type))
with Pre => Position /= No_Element
or else raise Constraint_Error,
Global =>
in all;
procedure Query_Element
(Container :
in Vector;
Position :
in Cursor;
Process :
not null access procedure (Element :
in Element_Type))
with Pre => (Position /= No_Element
or else raise Constraint_Error)
and then
(Has_Element (Container, Position)
or else raise Program_Error);
procedure Update_Element
(Container :
in out Vector;
Index :
in Index_Type;
Process :
not null access procedure
(Element :
in out Element_Type))
with Pre => Index
in
First_Index (Container) .. Last_Index (Container)
or else raise Constraint_Error;
procedure Update_Element
(Container :
in out Vector;
Position :
in Cursor;
Process :
not null access procedure
(Element :
in out Element_Type))
with Pre => (Position /= No_Element
or else raise Constraint_Error)
and then
(Has_Element (Container, Position)
or else raise Program_Error);
type Constant_Reference_Type
(Element : not null access constant Element_Type) is private
with Implicit_Dereference => Element,
Nonblocking, Global => in out synchronized,
Default_Initial_Condition => (raise Program_Error);
type Reference_Type (Element :
not null access Element_Type)
is private
with Implicit_Dereference => Element,
Nonblocking, Global =>
in out synchronized,
Default_Initial_Condition => (
raise Program_Error);
function Constant_Reference (Container :
aliased in Vector;
Index :
in Index_Type)
return Constant_Reference_Type
with Pre => Index
in
First_Index (Container) .. Last_Index (Container)
or else raise Constraint_Error,
Post => Tampering_With_Cursors_Prohibited (Container),
Nonblocking, Global =>
null, Use_Formal =>
null;
function Reference (Container :
aliased in out Vector;
Index :
in Index_Type)
return Reference_Type
with Pre => Index
in
First_Index (Container) .. Last_Index (Container)
or else raise Constraint_Error,
Post => Tampering_With_Cursors_Prohibited (Container),
Nonblocking, Global =>
null, Use_Formal =>
null;
function Constant_Reference (Container :
aliased in Vector;
Position :
in Cursor)
return Constant_Reference_Type
with Pre => (Position /= No_Element
or else raise Constraint_Error)
and then
(Has_Element (Container, Position)
or else raise Program_Error),
Post => Tampering_With_Cursors_Prohibited (Container),
Nonblocking, Global =>
null, Use_Formal =>
null;
function Reference (Container :
aliased in out Vector;
Position :
in Cursor)
return Reference_Type
with Pre => (Position /= No_Element
or else raise Constraint_Error)
and then
(Has_Element (Container, Position)
or else raise Program_Error),
Post => Tampering_With_Cursors_Prohibited (Container),
Nonblocking, Global =>
null, Use_Formal =>
null;
procedure Assign (Target :
in out Vector; Source :
in Vector)
with Pre =>
not Tampering_With_Cursors_Prohibited (Target)
or else raise Program_Error,
Post => Length (Source) = Length (Target)
and then
Capacity (Target) >= Length (Target);
function Copy (Source : Vector; Capacity : Count_Type := 0)
return Vector
with Pre => Capacity = 0
or else Capacity >= Length (Source)
or else raise Capacity_Error,
Post => Length (Copy'Result) = Length (Source)
and then
not Tampering_With_Elements_Prohibited (Copy'Result)
and then
not Tampering_With_Cursors_Prohibited (Copy'Result)
and then
Copy'Result.Capacity >= (
if Capacity = 0
then
Length (Source)
else Capacity);
procedure Move (Target :
in out Vector;
Source :
in out Vector)
with Pre => (
not Tampering_With_Cursors_Prohibited (Target)
or else raise Program_Error)
and then
(
not Tampering_With_Cursors_Prohibited (Source)
or else raise Program_Error),
Post => (
if not Target'Has_Same_Storage (Source)
then
Length (Target) = Length (Source)'Old
and then
Length (Source) = 0
and then
Capacity (Target) >= Length (Source)'Old);
procedure Insert_Vector (Container :
in out Vector;
Before :
in Extended_Index;
New_Item :
in Vector)
with Pre => (
not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error)
and then
(Before
in
First_Index (Container) .. Last_Index (Container) + 1
or else raise Constraint_Error)
and then
(Length (Container) <= Maximum_Length - Length (New_Item)
or else raise Constraint_Error),
Post => Length (Container)'Old + Length (New_Item) =
Length (Container)
and then
Capacity (Container) >= Length (Container);
procedure Insert_Vector (Container :
in out Vector;
Before :
in Cursor;
New_Item :
in Vector)
with Pre => (
not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error)
and then
(Before = No_Element
or else
Has_Element (Container, Before)
or else raise Program_Error)
and then
(Length (Container) <= Maximum_Length - Length (New_Item)
or else raise Constraint_Error),
Post => Length (Container)'Old + Length (New_Item) =
Length (Container)
and then
Capacity (Container) >= Length (Container);
procedure Insert_Vector (Container :
in out Vector;
Before :
in Cursor;
New_Item :
in Vector;
Position :
out Cursor)
with Pre => (
not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error)
and then
(Before = No_Element
or else
Has_Element (Container, Before)
or else raise Program_Error)
and then
(Length (Container) <= Maximum_Length - Length (New_Item)
or else raise Constraint_Error),
Post => Length (Container)'Old + Length (New_Item) =
Length (Container)
and then
Has_Element (Container, Position)
and then
Capacity (Container) >= Length (Container);
procedure Insert (Container :
in out Vector;
Before :
in Extended_Index;
New_Item :
in Element_Type;
Count :
in Count_Type := 1)
with Pre => (
not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error)
and then
(Before
in
First_Index (Container) .. Last_Index (Container) + 1
or else raise Constraint_Error)
and then
(Length (Container) <= Maximum_Length - Count
or else raise Constraint_Error),
Post => Length (Container)'Old + Count =
Length (Container)
and then
Capacity (Container) >= Length (Container);
procedure Insert (Container :
in out Vector;
Before :
in Cursor;
New_Item :
in Element_Type;
Count :
in Count_Type := 1)
with Pre => (
not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error)
and then
(Before = No_Element
or else
Has_Element (Container, Before)
or else raise Program_Error)
and then
(Length (Container) <= Maximum_Length - Count
or else raise Constraint_Error),
Post => Length (Container)'Old + Count =
Length (Container)
and then
Capacity (Container) >= Length (Container);
procedure Insert (Container :
in out Vector;
Before :
in Cursor;
New_Item :
in Element_Type;
Position :
out Cursor;
Count :
in Count_Type := 1)
with Pre => (
not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error)
and then
(Before = No_Element
or else
Has_Element (Container, Before)
or else raise Program_Error)
and then
(Length (Container) <= Maximum_Length - Count
or else raise Constraint_Error),
Post => Length (Container)'Old + Count =
Length (Container)
and then
Has_Element (Container, Position)
and then
Capacity (Container) >= Length (Container);
procedure Insert (Container :
in out Vector;
Before :
in Extended_Index;
Count :
in Count_Type := 1)
with Pre => (
not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error)
and then
(Before
in
First_Index (Container) .. Last_Index (Container) + 1
or else raise Constraint_Error)
and then
(Length (Container) <= Maximum_Length - Count
or else raise Constraint_Error),
Post => Length (Container)'Old + Count =
Length (Container)
and then
Capacity (Container) >= Length (Container);
procedure Insert (Container :
in out Vector;
Before :
in Cursor;
Position :
out Cursor;
Count :
in Count_Type := 1)
with Pre => (
not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error)
and then
(Before = No_Element
or else
Has_Element (Container, Before)
or else raise Program_Error)
and then
(Length (Container) <= Maximum_Length - Count
or else raise Constraint_Error),
Post => Length (Container)'Old + Count = Length (Container)
and then Has_Element (Container, Position)
and then
Capacity (Container) >= Length (Container);
procedure Prepend_Vector (Container :
in out Vector;
New_Item :
in Vector)
with Pre => (
not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error)
and then
(Length (Container) <= Maximum_Length - Length (New_Item)
or else raise Constraint_Error),
Post => Length (Container)'Old + Length (New_Item) =
Length (Container)
and then
Capacity (Container) >= Length (Container);
procedure Prepend (Container :
in out Vector;
New_Item :
in Element_Type;
Count :
in Count_Type := 1)
with Pre => (
not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error)
and then
(Length (Container) <= Maximum_Length - Count
or else raise Constraint_Error),
Post => Length (Container)'Old + Count =
Length (Container)
and then
Capacity (Container) >= Length (Container);
procedure Append_Vector (Container :
in out Vector;
New_Item :
in Vector)
with Pre => (
not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error)
and then
(Length (Container) <= Maximum_Length - Length (New_Item)
or else raise Constraint_Error),
Post => Length (Container)'Old + Length (New_Item) =
Length (Container)
and then
Capacity (Container) >= Length (Container);
procedure Append (Container :
in out Vector;
New_Item :
in Element_Type;
Count :
in Count_Type)
with Pre => (
not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error)
and then
(Length (Container) <= Maximum_Length - Count
or else raise Constraint_Error),
Post =>
Length (Container)'Old + Count = Length (Container)
and then
Capacity (Container) >= Length (Container);
procedure Append (Container :
in out Vector;
New_Item :
in Element_Type)
with Pre => (
not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error)
and then
(Length (Container) <= Maximum_Length - 1
or else raise Constraint_Error),
Post => Length (Container)'Old + 1 = Length (Container)
and then
Capacity (Container) >= Length (Container);
procedure Insert_Space (Container :
in out Vector;
Before :
in Extended_Index;
Count :
in Count_Type := 1)
with Pre => (
not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error)
and then
(Before
in
First_Index (Container) .. Last_Index (Container) + 1
or else raise Constraint_Error)
and then
(Length (Container) <= Maximum_Length - Count
or else raise Constraint_Error),
Post => Length (Container)'Old + Count =
Length (Container)
and then
Capacity (Container) >= Length (Container);
procedure Insert_Space (Container :
in out Vector;
Before :
in Cursor;
Position :
out Cursor;
Count :
in Count_Type := 1)
with Pre => (
not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error)
and then
(Before = No_Element
or else
Has_Element (Container, Before)
or else raise Program_Error)
and then
(Length (Container) <= Maximum_Length - Count
or else raise Constraint_Error),
Post => Length (Container)'Old + Count =
Length (Container)
and then
Has_Element (Container, Position)
and then
Capacity (Container) >= Length (Container);
procedure Delete (Container :
in out Vector;
Index :
in Extended_Index;
Count :
in Count_Type := 1)
with Pre => (
not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error)
and then
(Index
in
First_Index (Container) .. Last_Index (Container) + 1
or else raise Constraint_Error),
Post => Length (Container)'Old - Count <=
Length (Container);
procedure Delete (Container :
in out Vector;
Position :
in out Cursor;
Count :
in Count_Type := 1)
with Pre => (
not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error)
and then
(Position /= No_Element
or else raise Constraint_Error)
and then
(Has_Element (Container, Position)
or else raise Program_Error),
Post => Length (Container)'Old - Count <=
Length (Container)
and then
Position = No_Element;
procedure Delete_First (Container :
in out Vector;
Count :
in Count_Type := 1)
with Pre =>
not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error,
Post => Length (Container)'Old - Count <= Length (Container);
procedure Delete_Last (Container :
in out Vector;
Count :
in Count_Type := 1)
with Pre =>
not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error,
Post => Length (Container)'Old - Count <= Length (Container);
procedure Reverse_Elements (Container :
in out Vector)
with Pre =>
not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error;
procedure Swap (Container :
in out Vector;
I, J :
in Index_Type)
with Pre => (
not Tampering_With_Elements_Prohibited (Container)
or else raise Program_Error)
and then
(I
in First_Index (Container) .. Last_Index (Container)
or else raise Constraint_Error)
and then
(J
in First_Index (Container) .. Last_Index (Container)
or else raise Constraint_Error);
procedure Swap (Container :
in out Vector;
I, J :
in Cursor)
with Pre => (
not Tampering_With_Elements_Prohibited (Container)
or else raise Program_Error)
and then
(I /= No_Element
or else Constraint_Error)
and then
(J /= No_Element
or else Constraint_Error)
and then
(Has_Element (Container, I)
or else raise Program_Error)
and then
(Has_Element (Container, J)
or else raise Program_Error);
function First_Index (Container : Vector)
return Index_Type
with Nonblocking, Global =>
null, Use_Formal =>
null,
Post => First_Index'Result = Index_Type'First;
function First (Container : Vector)
return Cursor
with Nonblocking, Global =>
null, Use_Formal =>
null,
Post => (
if not Is_Empty (Container)
then Has_Element (Container, First'Result)
else First'Result = No_Element);
function First_Element (Container : Vector)
return Element_Type
with Pre => (
not Is_Empty (Container)
or else raise Constraint_Error);
function Last_Index (Container : Vector)
return Extended_Index
with Nonblocking, Global =>
null, Use_Formal =>
null,
Post => (
if Length (Container) = 0
then Last_Index'Result = No_Index
else Count_Type(Last_Index'Result - Index_Type'First) =
Length (Container) - 1);
function Last (Container : Vector)
return Cursor
with Nonblocking, Global =>
null, Use_Formal =>
null,
Post => (
if not Is_Empty (Container)
then Has_Element (Container, Last'Result)
else Last'Result = No_Element);
function Last_Element (Container : Vector)
return Element_Type
with Pre => (
not Is_Empty (Container)
or else raise Constraint_Error);
function Next (Position : Cursor)
return Cursor
with Nonblocking, Global =>
in all, Use_Formal =>
null,
Post => (
if Position = No_Element
then Next'Result = No_Element);
function Next (Container : Vector; Position : Cursor)
return Cursor
with Nonblocking, Global =>
null, Use_Formal =>
null,
Pre => Position = No_Element
or else
Has_Element (Container, Position)
or else raise Program_Error,
Post => (
if Position = No_Element
then Next'Result = No_Element
elsif Has_Element (Container, Next'Result)
then
To_Index (Container, Next'Result) =
To_Index (Container, Position) + 1
elsif Next'Result = No_Element
then
Position = Last (Container)
else False);
procedure Next (Position :
in out Cursor)
with Nonblocking, Global =>
in all, Use_Formal =>
null;
procedure Next (Container :
in Vector;
Position :
in out Cursor)
with Nonblocking, Global =>
null, Use_Formal =>
null,
Pre => Position = No_Element
or else
Has_Element (Container, Position)
or else raise Program_Error,
Post => (
if Position /= No_Element
then Has_Element (Container, Position));
function Previous (Position : Cursor)
return Cursor
with Nonblocking, Global =>
in all, Use_Formal =>
null,
Post => (
if Position = No_Element
then Previous'Result = No_Element);
function Previous (Container : Vector;
Position : Cursor)
return Cursor
with Nonblocking, Global =>
null, Use_Formal =>
null,
Pre => Position = No_Element
or else
Has_Element (Container, Position)
or else raise Program_Error,
Post => (
if Position = No_Element
then Previous'Result = No_Element
elsif Has_Element (Container, Previous'Result)
then
To_Index (Container, Previous'Result) =
To_Index (Container, Position) - 1
elsif Previous'Result = No_Element
then
Position = First (Container)
else False);
procedure Previous (Position :
in out Cursor)
with Nonblocking, Global =>
in all, Use_Formal =>
null;
procedure Previous (Container :
in Vector;
Position :
in out Cursor)
with Nonblocking, Global =>
null, Use_Formal =>
null,
Pre => Position = No_Element
or else
Has_Element (Container, Position)
or else raise Program_Error,
Post => (
if Position /= No_Element
then Has_Element (Container, Position));
function Find_Index (Container : Vector;
Item : Element_Type;
Index : Index_Type := Index_Type'First)
return Extended_Index;
function Find (Container : Vector;
Item : Element_Type;
Position : Cursor := No_Element)
return Cursor
with Pre => Position = No_Element
or else
Has_Element (Container, Position)
or else raise Program_Error,
Post => (
if Find'Result /= No_Element
then Has_Element (Container, Find'Result));
function Reverse_Find_Index (Container : Vector;
Item : Element_Type;
Index : Index_Type := Index_Type'Last)
return Extended_Index;
function Reverse_Find (Container : Vector;
Item : Element_Type;
Position : Cursor := No_Element)
return Cursor
with Pre => Position = No_Element
or else
Has_Element (Container, Position)
or else raise Program_Error,
Post => (
if Reverse_Find'Result /= No_Element
then Has_Element (Container, Reverse_Find'Result));
function Contains (Container : Vector;
Item : Element_Type)
return Boolean;
This paragraph
was deleted.
procedure Iterate
(Container :
in Vector;
Process :
not null access procedure (Position :
in Cursor))
with Allows_Exit;
procedure Reverse_Iterate
(Container :
in Vector;
Process :
not null access procedure (Position :
in Cursor))
with Allows_Exit;
function Iterate (Container :
in Vector)
return Vector_Iterator_Interfaces.Parallel_Reversible_Iterator'Class
with Post => Tampering_With_Cursors_Prohibited (Container);
function Iterate (Container :
in Vector; Start :
in Cursor)
return Vector_Iterator_Interfaces.Reversible_Iterator'Class
with Pre => (Start /= No_Element
or else raise Constraint_Error)
and then
(Has_Element (Container, Start)
or else raise Program_Error),
Post => Tampering_With_Cursors_Prohibited (Container);
generic
with function "<" (Left, Right : Element_Type)
return Boolean is <>;
package Generic_Sorting
with Nonblocking, Global =>
null is
function Is_Sorted (Container : Vector)
return Boolean;
procedure Sort (Container :
in out Vector)
with Pre =>
not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error;
procedure Merge (Target :
in out Vector;
Source :
in out Vector)
with Pre => (
not Tampering_With_Cursors_Prohibited (Target)
or else raise Program_Error)
and then
(
not Tampering_With_Cursors_Prohibited (Source)
or else raise Program_Error)
and then
(Length (Target) <= Maximum_Length - Length (Source)
or else raise Constraint_Error)
and then
((Length (Source) = 0
or else
not Target'Has_Same_Storage (Source))
or else raise Program_Error),
Post => (
declare
Result_Length :
constant Count_Type :=
Length (Source)'Old + Length (Target)'Old;
begin
(Length (Source) = 0
and then
Length (Target) = Result_Length
and then
Capacity (Target) >= Result_Length));
end Generic_Sorting;
type Vector (Base :
not null access Vectors.Vector)
is
tagged limited private
with Constant_Indexing => Constant_Reference,
Variable_Indexing => Reference,
Default_Iterator => Iterate,
Iterator_Element => Element_Type,
Stable_Properties => (Length, Capacity),
Global =>
null,
Default_Initial_Condition => Length (Vector) = 0,
Preelaborable_Initialization;
type Cursor
is private
with Preelaborable_Initialization;
Empty_Vector :
constant Vector;
No_Element :
constant Cursor;
function Has_Element (Position : Cursor)
return Boolean
with Nonblocking, Global =>
in all, Use_Formal =>
null;
package Vector_Iterator_Interfaces
is new
Ada.Iterator_Interfaces (Cursor, Has_Element);
procedure Assign (Target :
in out Vectors.Vector;
Source :
in Vector)
with Post => Length (Source) = Length (Target)
and then
Capacity (Target) >= Length (Target);
function Copy (Source : Vectors.Vector)
return Vector
with Post => Length (Copy'Result) = Length (Source);
type Constant_Reference_Type
(Element :
not null access constant Element_Type)
is private
with Implicit_Dereference => Element,
Nonblocking, Global =>
null, Use_Formal =>
null,
Default_Initial_Condition => (
raise Program_Error);
type Reference_Type
(Element :
not null access Element_Type)
is private
with Implicit_Dereference => Element,
Nonblocking, Global =>
null, Use_Formal =>
null,
Default_Initial_Condition => (
raise Program_Error);
-- Additional subprograms as described in the text
-- are declared here.
private
... -- not specified by the language
end Stable;
private
... -- not specified by the language
end Ada.Containers.Vectors;
The actual function for the generic formal function
"=" on Element_Type values is expected to define a reflexive
and symmetric relationship and return the same result value each time
it is called with a particular pair of values. If it behaves in some
other manner, the functions defined to use it return an unspecified value.
The exact arguments and number of calls of this generic formal function
by the functions defined to use it are unspecified.
The type Vector is used to represent vectors. The
type Vector needs finalization
(see
7.6).
Empty_Vector represents the empty vector object.
It has a length of 0. If an object of type Vector is not otherwise initialized,
it is initialized to the same value as Empty_Vector.
No_Element represents a cursor that designates no
element. If an object of type Cursor is not otherwise initialized, it
is initialized to the same value as No_Element.
The primitive "=" operator for type Cursor
returns True if both cursors are No_Element, or designate the same element
in the same container.
Execution of the default implementation of the Input,
Output, Read, or Write attribute of type Cursor raises Program_Error.
Vector'Write for a Vector object V writes
Length(V) elements of the vector to the stream. It may also write
additional information about the vector.
Vector'Read reads the representation of a vector
from the stream, and assigns to Item a vector with the same length
and elements as was written by Vector'Write.
No_Index represents a position that does not correspond
to any element. The subtype Extended_Index includes the indices covered
by Index_Type plus the value No_Index and, if it exists, the successor
to the Index_Type'Last.
Some operations
check for “tampering with cursors” of a container because
they depend on the set of elements of the container remaining constant,
and others check for “tampering with elements” of a container
because they depend on elements of the container not being replaced.
When tampering with cursors is
prohibited
for a particular vector object
V, Program_Error
is propagated by the finalization of
V, as well as by a call that
passes
V to certain of the operations of this package, as indicated
by the precondition of such an operation. Similarly, when tampering with
elements is
prohibited for
V, Program_Error is propagated
by a call that passes
V to certain of the other operations of
this package, as indicated by the precondition of such an operation.
Paragraphs 91 through
97 are removed as preconditions now describe these rules.
function Has_Element (Position : Cursor) return Boolean
with Nonblocking, Global => in all, Use_Formal => null;
Returns True if
Position designates an element, and returns False otherwise.
function Has_Element (Container : Vector; Position : Cursor)
return Boolean
with Nonblocking, Global =>
null, Use_Formal =>
null;
Returns True if
Position designates an element in Container, and returns False otherwise.
function "=" (Left, Right : Vector) return Boolean;
If Left and Right
denote the same vector object, then the function returns True. If Left
and Right have different lengths, then the function returns False. Otherwise,
it compares each element in Left to the corresponding element in Right
using the generic formal equality operator. If any such comparison returns
False, the function returns False; otherwise, it returns True. Any exception
raised during evaluation of element equality is propagated.
function Tampering_With_Cursors_Prohibited
(Container : Vector) return Boolean
with Nonblocking, Global => null, Use_Formal => null;
Returns True if
tampering with cursors or tampering with elements is currently prohibited
for Container, and returns False otherwise.
function Tampering_With_Elements_Prohibited
(Container : Vector) return Boolean
with Nonblocking, Global => null, Use_Formal => null;
Always returns False,
regardless of whether tampering with elements is prohibited.
function Maximum_Length return Count_Type
with Nonblocking, Global => null, Use_Formal => null;
Returns the maximum
Length of a Vector, based on the index type.
function Empty (Capacity : Count_Type := implementation-defined)
return Vector
with Pre => Capacity <= Maximum_Length
or else raise Constraint_Error,
Post =>
Capacity (Empty'Result) >= Capacity and then
not Tampering_With_Elements_Prohibited (Empty'Result) and then
not Tampering_With_Cursors_Prohibited (Empty'Result) and then
Length (Empty'Result) = 0;
Returns an empty
vector.
function To_Vector (Length : Count_Type) return Vector
with Pre => Length <= Maximum_Length or else raise Constraint_Error,
Post =>
To_Vector'Result.Length = Length and then
not Tampering_With_Elements_Prohibited (To_Vector'Result)
and then
not Tampering_With_Cursors_Prohibited (To_Vector'Result)
and then
To_Vector'Result.Capacity >= Length;
Returns a vector
with a length of Length, filled with empty elements.
function To_Vector
(New_Item : Element_Type;
Length : Count_Type) return Vector
with Pre => Length <= Maximum_Length or else raise Constraint_Error,
Post =>
To_Vector'Result.Length = Length and then
not Tampering_With_Elements_Prohibited (To_Vector'Result)
and then
not Tampering_With_Cursors_Prohibited (To_Vector'Result)
and then
To_Vector'Result.Capacity >= Length;
Returns a vector
with a length of Length, filled with elements initialized to the value
New_Item.
function "&" (Left, Right : Vector) return Vector
with Pre => Length (Left) <= Maximum_Length - Length (Right)
or else raise Constraint_Error,
Post => Length (Vectors."&"'Result) =
Length (Left) + Length (Right) and then
not Tampering_With_Elements_Prohibited (Vectors."&"'Result)
and then
not Tampering_With_Cursors_Prohibited (Vectors."&"'Result)
and then
Vectors."&"'Result.Capacity >=
Length (Left) + Length (Right);
Returns a vector
comprising the elements of Left followed by the elements of Right.
function "&" (Left : Vector;
Right : Element_Type) return Vector
with Pre => Length (Left) <= Maximum_Length - 1
or else raise Constraint_Error,
Post => Vectors."&"'Result.Length = Length (Left) + 1 and then
not Tampering_With_Elements_Prohibited (Vectors."&"'Result)
and then
not Tampering_With_Cursors_Prohibited (Vectors."&"'Result)
and then
Vectors."&"'Result.Capacity >= Length (Left) + 1;
Returns a vector
comprising the elements of Left followed by the element Right.
function "&" (Left : Element_Type;
Right : Vector) return Vector
with Pre => Length (Right) <= Maximum_Length - 1
or else raise Constraint_Error,
Post => Length (Vectors."&"'Result) = Length (Right) + 1 and then
not Tampering_With_Elements_Prohibited (Vectors."&"'Result)
and then
not Tampering_With_Cursors_Prohibited (Vectors."&"'Result)
and then
Vectors."&"'Result.Capacity >= Length (Right) + 1;
Returns a vector
comprising the element Left followed by the elements of Right.
function "&" (Left, Right : Element_Type) return Vector
with Pre => Maximum_Length >= 2 or else raise Constraint_Error,
Post => Length ("&"'Result) = 2 and then
not Tampering_With_Elements_Prohibited (Vectors."&"'Result)
and then
not Tampering_With_Cursors_Prohibited (Vectors."&"'Result)
and then
Vectors."&"'Result.Capacity >= 2;
Returns a vector
comprising the element Left followed by the element Right.
function Capacity (Container : Vector) return Count_Type
with Nonblocking, Global => null, Use_Formal => null;
Returns the capacity
of Container.
procedure Reserve_Capacity (Container : in out Vector;
Capacity : in Count_Type)
with Pre => not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error,
Post => Container.Capacity >= Capacity;
If the capacity
of Container is already greater than or equal to Capacity, then Reserve_Capacity
has no effect. Otherwise, Reserve_Capacity allocates additional storage
as necessary to ensure that the length of the resulting vector can become
at least the value Capacity without requiring an additional call to Reserve_Capacity,
and is large enough to hold the current length of Container. Reserve_Capacity
then, as necessary, moves elements into the new storage and deallocates
any storage no longer needed. Any exception raised during allocation
is propagated and Container is not modified.
function Length (Container : Vector) return Count_Type
with Nonblocking, Global => null, Use_Formal => null;
Returns the number
of elements in Container.
procedure Set_Length (Container : in out Vector;
Length : in Count_Type)
with Pre => (not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error) and then
(Length <= Maximum_Length or else raise Constraint_Error),
Post => Container.Length = Length and then
Capacity (Container) >= Length;
If Length is larger
than the capacity of Container, Set_Length calls Reserve_Capacity (Container,
Length), then sets the length of the Container to Length. If Length is
greater than the original length of Container, empty elements are added
to Container; otherwise, elements are removed from Container.
function Is_Empty (Container : Vector) return Boolean
with Nonblocking, Global => null, Use_Formal => null,
Post => Is_Empty'Result = (Length (Container) = 0);
Returns True if
Container is empty.
procedure Clear (Container : in out Vector)
with Pre => not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error,
Post => Length (Container) = 0;
Removes all the
elements from Container. The capacity of Container does not change.
function To_Cursor (Container : Vector;
Index : Extended_Index) return Cursor
with Post => (if Index in
First_Index (Container) .. Last_Index (Container)
then Has_Element (Container, To_Cursor'Result)
else To_Cursor'Result = No_Element),
Nonblocking, Global => null, Use_Formal => null;
Returns a cursor
designating the element at position Index in Container; returns No_Element
if Index does not designate an element. For the purposes of determining
whether the parameters overlap in a call to To_Cursor, the Container
parameter is not considered to overlap with any object (including itself).
function To_Index (Position : Cursor) return Extended_Index
with Nonblocking, Global => in all, Use_Formal => null;
If Position is No_Element,
No_Index is returned. Otherwise, the index (within its containing vector)
of the element designated by Position is returned.
function To_Index (Container : Vector;
Position : Cursor) return Extended_Index
with Pre => Position = No_Element or else
Has_Element (Container, Position) or else
raise Program_Error,
Post => (if Position = No_Element then To_Index'Result = No_Index
else To_Index'Result in First_Index (Container) ..
Last_Index (Container)),
Nonblocking, Global => null, Use_Formal => null;
Returns the index
(within Container) of the element designated by Position; returns No_Index
if Position does not designate an element. For the purposes of determining
whether the parameters overlap in a call to To_Index, the Container parameter
is not considered to overlap with any object (including itself).
function Element (Container : Vector;
Index : Index_Type)
return Element_Type
with Pre => Index in First_Index (Container) .. Last_Index (Container)
or else raise Constraint_Error,
Nonblocking, Global => null, Use_Formal => Element_Type;
Element returns
the element at position Index.
function Element (Position : Cursor) return Element_Type
with Pre => Position /= No_Element or else raise Constraint_Error,
Nonblocking, Global => in all, Use_Formal => Element_Type;
Element returns
the element designated by Position.
function Element (Container : Vector;
Position : Cursor) return Element_Type
with Pre => (Position /= No_Element
or else raise Constraint_Error) and then
(Has_Element (Container, Position)
or else raise Program_Error),
Nonblocking, Global => null, Use_Formal => Element_Type;
Element returns
the element designated by Position in Container.
procedure Replace_Element (Container : in out Vector;
Index : in Index_Type;
New_Item : in Element_Type)
with Pre => (not Tampering_With_Elements_Prohibited (Container)
or else raise Program_Error) and then
(Index in First_Index (Container) .. Last_Index (Container)
or else raise Constraint_Error);
Replace_Element
assigns the value New_Item to the element at position Index. Any exception
raised during the assignment is propagated. The element at position Index
is not an empty element after successful call to Replace_Element. For
the purposes of determining whether the parameters overlap in a call
to Replace_Element, the Container parameter is not considered to overlap
with any object (including itself), and the Index parameter is considered
to overlap with the element at position Index.
procedure Replace_Element (Container : in out Vector;
Position : in Cursor;
New_Item : in Element_Type)
with Pre => (not Tampering_With_Elements_Prohibited (Container)
or else raise Program_Error) and then
(Position /= No_Element
or else raise Constraint_Error) and then
(Has_Element (Container, Position)
or else raise Program_Error);
Replace_Element
assigns New_Item to the element designated by Position. Any exception
raised during the assignment is propagated. The element at Position is
not an empty element after successful call to Replace_Element. For the
purposes of determining whether the parameters overlap in a call to Replace_Element,
the Container parameter is not considered to overlap with any object
(including itself).
procedure Query_Element
(Container : in Vector;
Index : in Index_Type;
Process : not null access procedure (Element : in Element_Type))
with Pre => Index in First_Index (Container) .. Last_Index (Container)
or else raise Constraint_Error;
Query_Element calls
Process.all with the element at position Index as the argument.
Tampering with the elements of Container is prohibited during the execution
of the call on Process.all. Any exception raised by Process.all
is propagated.
procedure Query_Element
(Position : in Cursor;
Process : not null access procedure (Element : in Element_Type))
with Pre => Position /= No_Element or else raise Constraint_Error
Global => in all;
Query_Element calls
Process.all with the element designated by Position as the argument.
Tampering with the elements of the vector that contains the element designated
by Position is prohibited during the execution of the call on Process.all.
Any exception raised by Process.all is propagated.
procedure Query_Element
(Container : in Vector;
Position : in Cursor;
Process : not null access procedure (Element : in Element_Type))
with Pre => (Position /= No_Element
or else raise Constraint_Error) and then
(Has_Element (Container, Position)
or else raise Program_Error);
Query_Element calls
Process.all with the element designated by Position as the argument.
Tampering with the elements of Container is prohibited during the execution
of the call on Process.all. Any exception raised by Process.all
is propagated.
procedure Update_Element
(Container : in out Vector;
Index : in Index_Type;
Process : not null access procedure
(Element : in out Element_Type))
with Pre => Index in First_Index (Container) .. Last_Index (Container)
or else raise Constraint_Error;
Update_Element calls
Process.all with the element at position Index as the argument.
Tampering with the elements of Container is prohibited during the execution
of the call on Process.all. Any exception raised by Process.all
is propagated.
If Element_Type is unconstrained and definite,
then the actual Element parameter of Process.all shall be unconstrained.
The element at position
Index is not an empty element after successful completion of this operation.
procedure Update_Element
(Container : in out Vector;
Position : in Cursor;
Process : not null access procedure
(Element : in out Element_Type))
with Pre => (Position /= No_Element
or else raise Constraint_Error) and then
(Has_Element (Container, Position)
or else raise Program_Error);
Update_Element calls
Process.all with the element designated by Position as the argument.
Tampering with the elements of Container is prohibited during the execution
of the call on Process.all. Any exception raised by Process.all
is propagated.
If Element_Type is unconstrained and definite,
then the actual Element parameter of Process.all shall be unconstrained.
The element designated
by Position is not an empty element after successful completion of this
operation.
type Constant_Reference_Type
(Element : not null access constant Element_Type) is private
with Implicit_Dereference => Element,
Nonblocking, Global => in out synchronized,
Default_Initial_Condition => (raise Program_Error);
type Reference_Type (Element : not null access Element_Type) is private
with Implicit_Dereference => Element,
Nonblocking, Global => in out synchronized,
Default_Initial_Condition => (raise Program_Error);
The types Constant_Reference_Type
and Reference_Type need finalization.
This paragraph
was deleted.
function Constant_Reference (Container : aliased in Vector;
Index : in Index_Type)
return Constant_Reference_Type
with Pre => Index in First_Index (Container) .. Last_Index (Container)
or else raise Constraint_Error,
Post => Tampering_With_Cursors_Prohibited (Container),
Nonblocking, Global => null, Use_Formal => null;
This function (combined
with the Constant_Indexing and Implicit_Dereference aspects) provides
a convenient way to gain read access to an individual element of a vector
given an index value.
Constant_Reference returns an object whose discriminant
is an access value that designates the element at position Index. Tampering
with the elements of Container is prohibited while the object returned
by Constant_Reference exists and has not been finalized.
function Reference (Container : aliased in out Vector;
Index : in Index_Type)
return Reference_Type
with Pre => Index in First_Index (Container) .. Last_Index (Container)
or else raise Constraint_Error,
Post => Tampering_With_Cursors_Prohibited (Container),
Nonblocking, Global => null, Use_Formal => null;
This function (combined
with the Variable_Indexing and Implicit_Dereference aspects) provides
a convenient way to gain read and write access to an individual element
of a vector given an index value.
Reference returns an object whose discriminant
is an access value that designates the element at position Index. Tampering
with the elements of Container is prohibited while the object returned
by Reference exists and has not been finalized.
The element at position Index is not an empty
element after successful completion of this operation.
function Constant_Reference (Container : aliased in Vector;
Position : in Cursor)
return Constant_Reference_Type
with Pre => (Position /= No_Element
or else raise Constraint_Error) and then
(Has_Element (Container, Position)
or else raise Program_Error),
Post => Tampering_With_Cursors_Prohibited (Container),
Nonblocking, Global => null, Use_Formal => null;
This function (combined
with the Constant_Indexing and Implicit_Dereference aspects) provides
a convenient way to gain read access to an individual element of a vector
given a cursor.
Constant_Reference returns an object whose discriminant
is an access value that designates the element designated by Position.
Tampering with the elements of Container is prohibited while the object
returned by Constant_Reference exists and has not been finalized.
function Reference (Container : aliased in out Vector;
Position : in Cursor)
return Reference_Type
with Pre => (Position /= No_Element
or else raise Constraint_Error) and then
(Has_Element (Container, Position)
or else raise Program_Error),
Post => Tampering_With_Cursors_Prohibited (Container),
Nonblocking, Global => null, Use_Formal => null;
This function (combined
with the Variable_Indexing and Implicit_Dereference aspects) provides
a convenient way to gain read and write access to an individual element
of a vector given a cursor.
Reference returns an object whose discriminant
is an access value that designates the element designated by Position.
Tampering with the elements of Container is prohibited while the object
returned by Reference exists and has not been finalized.
The element designated by Position is not an empty
element after successful completion of this operation.
procedure Assign (Target : in out Vector; Source : in Vector)
with Pre => not Tampering_With_Cursors_Prohibited (Target)
or else raise Program_Error,
Post => Length (Source) = Length (Target) and then
Capacity (Target) >= Length (Target);
If Target denotes
the same object as Source, the operation has no effect. If the length
of Source is greater than the capacity of Target, Reserve_Capacity (Target,
Length (Source)) is called. The elements of Source are then copied to
Target as for an
assignment_statement
assigning Source to Target (this includes setting the length of Target
to be that of Source).
function Copy (Source : Vector; Capacity : Count_Type := 0)
return Vector
with Pre => Capacity = 0 or else Capacity >= Length (Source)
or else raise Capacity_Error,
Post => Length (Copy'Result) = Length (Source) and then
not Tampering_With_Elements_Prohibited (Copy'Result)
and then
not Tampering_With_Cursors_Prohibited (Copy'Result)
and then
Copy'Result.Capacity >= (if Capacity = 0 then
Length (Source) else Capacity);
Returns a vector
whose elements are initialized from the corresponding elements of Source.
procedure Move (Target : in out Vector;
Source : in out Vector)
with Pre => (not Tampering_With_Cursors_Prohibited (Target)
or else raise Program_Error) and then
(not Tampering_With_Cursors_Prohibited (Source)
or else raise Program_Error),
Post => (if not Target'Has_Same_Storage (Source) then
Length (Target) = Length (Source)'Old and then
Length (Source) = 0 and then
Capacity (Target) >= Length (Source)'Old);
If Target denotes
the same object as Source, then the operation has no effect. Otherwise,
Move first calls Reserve_Capacity (Target, Length (Source)) and then
Clear (Target); then, each element from Source is removed from Source
and inserted into Target in the original order.
procedure Insert_Vector (Container : in out Vector;
Before : in Extended_Index;
New_Item : in Vector)
with Pre => (not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error) and then
(Before in
First_Index (Container) .. Last_Index (Container) + 1
or else raise Constraint_Error) and then
(Length (Container) <= Maximum_Length - Length (New_Item)
or else raise Constraint_Error),
Post => Length (Container)'Old + Length (New_Item) =
Length (Container) and then
Capacity (Container) >= Length (Container);
If Length(New_Item) is 0, then Insert_Vector does
nothing. Otherwise, it computes the new length NL as the sum of
the current length and Length (New_Item); if the value of Last appropriate
for length NL would be greater than Index_Type'Last, then Constraint_Error
is propagated.
If the current vector
capacity is less than NL, Reserve_Capacity (Container, NL)
is called to increase the vector capacity. Then Insert_Vector slides
the elements in the range Before .. Last_Index (Container) up by Length(New_Item)
positions, and then copies the elements of New_Item to the positions
starting at Before. Any exception raised during the copying is propagated.
procedure Insert_Vector (Container : in out Vector;
Before : in Cursor;
New_Item : in Vector)
with Pre => (not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error) and then
(Before = No_Element or else
Has_Element (Container, Before)
or else raise Program_Error) and then
(Length (Container) <= Maximum_Length - Length (New_Item)
or else raise Constraint_Error),
Post => Length (Container)'Old + Length (New_Item) =
Length (Container) and then
Capacity (Container) >= Length (Container);
If Length(New_Item)
is 0, then Insert_Vector does nothing. If Before is No_Element, then
the call is equivalent to Insert_Vector (Container, Last_Index (Container)
+ 1, New_Item); otherwise, the call is equivalent to Insert_Vector (Container,
To_Index (Before), New_Item);
procedure Insert_Vector (Container : in out Vector;
Before : in Cursor;
New_Item : in Vector;
Position : out Cursor)
with Pre => (not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error) and then
(Before = No_Element or else
Has_Element (Container, Before)
or else raise Program_Error) and then
(Length (Container) <= Maximum_Length - Length (New_Item)
or else raise Constraint_Error),
Post => Length (Container)'Old + Length (New_Item) =
Length (Container) and then
Has_Element (Container, Position) and then
Capacity (Container) >= Length (Container);
If Before equals
No_Element, then let T be Last_Index (Container) + 1; otherwise,
let T be To_Index (Before). Insert_Vector (Container, T,
New_Item) is called, and then Position is set to To_Cursor (Container,
T).
procedure Insert (Container : in out Vector;
Before : in Extended_Index;
New_Item : in Element_Type;
Count : in Count_Type := 1)
with Pre => (not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error) and then
(Before in
First_Index (Container) .. Last_Index (Container) + 1
or else raise Constraint_Error) and then
(Length (Container) <= Maximum_Length - Count
or else raise Constraint_Error),
Post => Length (Container)'Old + Count = Length (Container) and then
Capacity (Container) >= Length (Container);
Equivalent to Insert
(Container, Before, To_Vector (New_Item, Count));
procedure Insert (Container : in out Vector;
Before : in Cursor;
New_Item : in Element_Type;
Count : in Count_Type := 1)
with Pre => (not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error) and then
(Before = No_Element or else
Has_Element (Container, Before)
or else raise Program_Error) and then
(Length (Container) <= Maximum_Length - Count
or else raise Constraint_Error),
Post => Length (Container)'Old + Count = Length (Container) and then
Capacity (Container) >= Length (Container);
Equivalent to Insert
(Container, Before, To_Vector (New_Item, Count));
procedure Insert (Container : in out Vector;
Before : in Cursor;
New_Item : in Element_Type;
Position : out Cursor;
Count : in Count_Type := 1)
with Pre => (not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error) and then
(Before = No_Element or else
Has_Element (Container, Before)
or else raise Program_Error) and then
(Length (Container) <= Maximum_Length - Count
or else raise Constraint_Error),
Post => Length (Container)'Old + Count = Length (Container) and then
Has_Element (Container, Position) and then
Capacity (Container) >= Length (Container);
Equivalent to Insert
(Container, Before, To_Vector (New_Item, Count), Position);
procedure Insert (Container : in out Vector;
Before : in Extended_Index;
Count : in Count_Type := 1)
with Pre => (not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error) and then
(Before in
First_Index (Container) .. Last_Index (Container) + 1
or else raise Constraint_Error) and then
(Length (Container) <= Maximum_Length - Count
or else raise Constraint_Error),
Post => Length (Container)'Old + Count = Length (Container) and then
Capacity (Container) >= Length (Container);
If Count is 0, then Insert does nothing. Otherwise,
it computes the new length NL as the sum of the current length
and Count; if the value of Last appropriate for length NL would
be greater than Index_Type'Last, then Constraint_Error is propagated.
If the current vector
capacity is less than
NL, Reserve_Capacity (Container,
NL)
is called to increase the vector capacity. Then Insert slides the elements
in the range Before .. Last_Index (Container) up by Count positions,
and then inserts elements that are initialized by default (see
3.3.1)
in the positions starting at Before.
procedure Insert (Container : in out Vector;
Before : in Cursor;
Position : out Cursor;
Count : in Count_Type := 1)
with Pre => (not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error) and then
(Before = No_Element or else
Has_Element (Container, Before)
or else raise Program_Error) and then
(Length (Container) <= Maximum_Length - Count
or else raise Constraint_Error),
Post => Length (Container)'Old + Count = Length (Container) and then
Has_Element (Container, Position) and then
Capacity (Container) >= Length (Container);
If Before equals
No_Element, then let T be Last_Index (Container) + 1; otherwise,
let T be To_Index (Before). Insert (Container, T, Count)
is called, and then Position is set to To_Cursor (Container, T).
procedure Prepend_Vector (Container : in out Vector;
New_Item : in Vector)
with Pre => (not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error) and then
(Length (Container) <= Maximum_Length - Length (New_Item)
or else raise Constraint_Error),
Post => Length (Container)'Old + Length (New_Item) =
Length (Container) and then
Capacity (Container) >= Length (Container);
Equivalent to Insert
(Container, First_Index (Container), New_Item).
procedure Prepend (Container : in out Vector;
New_Item : in Element_Type;
Count : in Count_Type := 1)
with Pre => (not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error) and then
(Length (Container) <= Maximum_Length - Count
or else raise Constraint_Error),
Post => Length (Container)'Old + Count = Length (Container) and then
Capacity (Container) >= Length (Container);
Equivalent to Insert
(Container, First_Index (Container), New_Item, Count).
procedure Append_Vector (Container : in out Vector;
New_Item : in Vector)
with Pre => (not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error) and then
(Length (Container) <= Maximum_Length - Length (New_Item)
or else raise Constraint_Error),
Post => Length (Container)'Old + Length (New_Item) =
Length (Container) and then
Capacity (Container) >= Length (Container);
Equivalent to Insert
(Container, Last_Index (Container) + 1, New_Item).
procedure Append (Container : in out Vector;
New_Item : in Element_Type;
Count : in Count_Type)
with Pre => (not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error) and then
(Length (Container) <= Maximum_Length - Count
or else raise Constraint_Error),
Post => Length (Container)'Old + Count = Length (Container) and then
Capacity (Container) >= Length (Container);
Equivalent to Insert
(Container, Last_Index (Container) + 1, New_Item, Count).
procedure Append (Container : in out Vector;
New_Item : in Element_Type)
with Pre => (not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error) and then
(Length (Container) <= Maximum_Length - 1
or else raise Constraint_Error),
Post => Length (Container)'Old + 1 = Length (Container) and then
Capacity (Container) >= Length (Container);
Equivalent to Insert
(Container, Last_Index (Container) + 1, New_Item, 1).
procedure Insert_Space (Container : in out Vector;
Before : in Extended_Index;
Count : in Count_Type := 1)
with Pre => (not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error) and then
(Before in
First_Index (Container) .. Last_Index (Container) + 1
or else raise Constraint_Error) and then
(Length (Container) <= Maximum_Length - Count
or else raise Constraint_Error),
Post => Length (Container)'Old + Count = Length (Container) and then
Capacity (Container) >= Length (Container);
If Count is 0, then Insert_Space does nothing.
Otherwise, it computes the new length NL as the sum of the current
length and Count; if the value of Last appropriate for length NL
would be greater than Index_Type'Last, then Constraint_Error is propagated.
If the current vector
capacity is less than NL, Reserve_Capacity (Container, NL)
is called to increase the vector capacity. Then Insert_Space slides the
elements in the range Before .. Last_Index (Container) up by Count positions,
and then inserts empty elements in the positions starting at Before.
procedure Insert_Space (Container : in out Vector;
Before : in Cursor;
Position : out Cursor;
Count : in Count_Type := 1)
with Pre => (not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error) and then
(Before = No_Element or else
Has_Element (Container, Before)
or else raise Program_Error) and then
(Length (Container) <= Maximum_Length - Count
or else raise Constraint_Error),
Post => Length (Container)'Old + Count = Length (Container) and then
Has_Element (Container, Position) and then
Capacity (Container) >= Length (Container);
If Before equals
No_Element, then let T be Last_Index (Container) + 1; otherwise,
let T be To_Index (Before). Insert_Space (Container, T,
Count) is called, and then Position is set to To_Cursor (Container, T).
procedure Delete (Container : in out Vector;
Index : in Extended_Index;
Count : in Count_Type := 1)
with Pre => (not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error) and then
(Index in
First_Index (Container) .. Last_Index (Container) + 1
or else raise Constraint_Error),
Post => Length (Container)'Old - Count <= Length (Container);
If Count is 0, Delete
has no effect. Otherwise, Delete slides the elements (if any) starting
at position Index + Count down to Index. Any exception raised during
element assignment is propagated.
procedure Delete (Container : in out Vector;
Position : in out Cursor;
Count : in Count_Type := 1)
with Pre => (not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error) and then
(Position /= No_Element
or else raise Constraint_Error) and then
(Has_Element (Container, Position)
or else raise Program_Error),
Post => Length (Container)'Old - Count <= Length (Container)
and then Position = No_Element;
Delete (Container,
To_Index (Position), Count) is called, and then Position is set to No_Element.
procedure Delete_First (Container : in out Vector;
Count : in Count_Type := 1)
with Pre => not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error,
Post => Length (Container)'Old - Count <= Length (Container);
Equivalent to Delete
(Container, First_Index (Container), Count).
procedure Delete_Last (Container : in out Vector;
Count : in Count_Type := 1)
with Pre => not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error,
Post => Length (Container)'Old - Count <= Length (Container);
If Length (Container)
<= Count, then Delete_Last is equivalent to Clear (Container). Otherwise,
it is equivalent to Delete (Container, Index_Type'Val(Index_Type'Pos(Last_Index
(Container)) – Count + 1), Count).
procedure Reverse_Elements (Container : in out Vector)
with Pre => not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error;
Reorders the elements
of Container in reverse order.
procedure Swap (Container : in out Vector;
I, J : in Index_Type)
with Pre => (not Tampering_With_Elements_Prohibited (Container)
or else raise Program_Error) and then
(I in First_Index (Container) .. Last_Index (Container)
or else raise Constraint_Error) and then
(J in First_Index (Container) .. Last_Index (Container)
or else raise Constraint_Error);
Swap exchanges the
values of the elements at positions I and J.
procedure Swap (Container : in out Vector;
I, J : in Cursor)
with Pre => (not Tampering_With_Elements_Prohibited (Container)
or else raise Program_Error) and then
(I /= No_Element or else Constraint_Error) and then
(J /= No_Element or else Constraint_Error) and then
(Has_Element (Container, I)
or else raise Program_Error) and then
(Has_Element (Container, J)
or else raise Program_Error);
Swap exchanges the
values of the elements designated by I and J.
function First_Index (Container : Vector) return Index_Type
with Nonblocking, Global => null, Use_Formal => null,
Post => First_Index'Result = Index_Type'First;
Returns the value
Index_Type'First.
function First (Container : Vector) return Cursor
with Nonblocking, Global => null, Use_Formal => null,
Post => (if not Is_Empty (Container)
then Has_Element (Container, First'Result)
else First'Result = No_Element);
If Container is
empty, First returns No_Element. Otherwise, it returns a cursor that
designates the first element in Container.
function First_Element (Container : Vector)
return Element_Type
with Pre => (not Is_Empty (Container)
or else raise Constraint_Error);
Equivalent to Element
(Container, First_Index (Container)).
function Last_Index (Container : Vector) return Extended_Index
with Nonblocking, Global => null, Use_Formal => null,
Post => (if Length (Container) = 0 then Last_Index'Result = No_Index
else Count_Type(Last_Index'Result - Index_Type'First) =
Length (Container) - 1);
If Container is
empty, Last_Index returns No_Index. Otherwise, it returns the position
of the last element in Container.
function Last (Container : Vector) return Cursor
with Nonblocking, Global => null, Use_Formal => null,
Post => (if not Is_Empty (Container)
then Has_Element (Container, Last'Result)
else Last'Result = No_Element);
If Container is
empty, Last returns No_Element. Otherwise, it returns a cursor that designates
the last element in Container.
function Last_Element (Container : Vector)
return Element_Type
with Pre => (not Is_Empty (Container)
or else raise Constraint_Error);
Equivalent to Element
(Container, Last_Index (Container)).
function Next (Position : Cursor) return Cursor
with Nonblocking, Global => in all, Use_Formal => null,
Post => (if Position = No_Element then Next'Result = No_Element);
If Position equals
No_Element or designates the last element of the container, then Next
returns the value No_Element. Otherwise, it returns a cursor that designates
the element with index To_Index (Position) + 1 in the same vector as
Position.
function Next (Container : Vector;
Position : Cursor) return Cursor
with Nonblocking, Global => null, Use_Formal => null,
Pre => Position = No_Element or else
Has_Element (Container, Position)
or else raise Program_Error,
Post => (if Position = No_Element then Next'Result = No_Element
elsif Has_Element (Container, Next'Result) then
To_Index (Container, Next'Result) =
To_Index (Container, Position) + 1
elsif Next'Result = No_Element then
Position = Last (Container)
else False);
Returns a cursor
designating the next element in Container, if any.
procedure Next (Position : in out Cursor)
with Nonblocking, Global => in all, Use_Formal => null;
Equivalent to Position
:= Next (Position).
procedure Next (Container : in Vector;
Position : in out Cursor)
with Nonblocking, Global => null, Use_Formal => null,
Pre => Position = No_Element or else
Has_Element (Container, Position)
or else raise Program_Error,
Post => (if Position /= No_Element
then Has_Element (Container, Position));
Equivalent to Position
:= Next (Container, Position).
function Previous (Position : Cursor) return Cursor
with Nonblocking, Global => in all, Use_Formal => null,
Post => (if Position = No_Element
then Previous'Result = No_Element);
If Position equals
No_Element or designates the first element of the container, then Previous
returns the value No_Element. Otherwise, it returns a cursor that designates
the element with index To_Index (Position) – 1 in the same vector
as Position.
function Previous (Container : Vector;
Position : Cursor) return Cursor
with Nonblocking, Global => null, Use_Formal => null,
Pre => Position = No_Element or else
Has_Element (Container, Position)
or else raise Program_Error,
Post => (if Position = No_Element then Previous'Result = No_Element
elsif Has_Element (Container, Previous'Result) then
To_Index (Container, Previous'Result) =
To_Index (Container, Position) - 1
elsif Previous'Result = No_Element then
Position = First (Container)
else False);
Returns a cursor
designating the previous element in Container, if any.
procedure Previous (Position : in out Cursor)
with Nonblocking, Global => in all, Use_Formal => null;
Equivalent to Position
:= Previous (Position).
procedure Previous (Container : in Vector;
Position : in out Cursor)
with Nonblocking, Global => null, Use_Formal => null,
Pre => Position = No_Element or else
Has_Element (Container, Position)
or else raise Program_Error,
Post => (if Position /= No_Element
then Has_Element (Container, Position));
Equivalent to Position
:= Previous (Container, Position).
function Find_Index (Container : Vector;
Item : Element_Type;
Index : Index_Type := Index_Type'First)
return Extended_Index;
Searches the elements
of Container for an element equal to Item (using the generic formal equality
operator). The search starts at position Index and proceeds towards Last_Index
(Container). If no equal element is found, then Find_Index returns No_Index.
Otherwise, it returns the index of the first equal element encountered.
function Find (Container : Vector;
Item : Element_Type;
Position : Cursor := No_Element)
return Cursor
with Pre => Position = No_Element or else
Has_Element (Container, Position)
or else raise Program_Error,
Post => (if Find'Result /= No_Element
then Has_Element (Container, Find'Result));
Find searches the
elements of Container for an element equal to Item (using the generic
formal equality operator). The search starts at the first element if
Position equals No_Element, and at the element designated by Position
otherwise. It proceeds towards the last element of Container. If no equal
element is found, then Find returns No_Element. Otherwise, it returns
a cursor designating the first equal element encountered.
function Reverse_Find_Index (Container : Vector;
Item : Element_Type;
Index : Index_Type := Index_Type'Last)
return Extended_Index;
Searches the elements
of Container for an element equal to Item (using the generic formal equality
operator). The search starts at position Index or, if Index is greater
than Last_Index (Container), at position Last_Index (Container). It proceeds
towards First_Index (Container). If no equal element is found, then Reverse_Find_Index
returns No_Index. Otherwise, it returns the index of the first equal
element encountered.
function Reverse_Find (Container : Vector;
Item : Element_Type;
Position : Cursor := No_Element)
return Cursor
with Pre => Position = No_Element or else
Has_Element (Container, Position)
or else raise Program_Error,
Post => (if Reverse_Find'Result /= No_Element
then Has_Element (Container, Reverse_Find'Result));
Reverse_Find searches
the elements of Container for an element equal to Item (using the generic
formal equality operator). The search starts at the last element if Position
equals No_Element, and at the element designated by Position otherwise.
It proceeds towards the first element of Container. If no equal element
is found, then Reverse_Find returns No_Element. Otherwise, it returns
a cursor designating the first equal element encountered.
function Contains (Container : Vector;
Item : Element_Type) return Boolean;
Equivalent to Has_Element
(Find (Container, Item)).
Paragraphs 225
and 226 were moved above.
procedure Iterate
(Container : in Vector;
Process : not null access procedure (Position : in Cursor))
with Allows_Exit;
Invokes Process.all
with a cursor that designates each element in Container, in index order.
Tampering with the cursors of Container is prohibited during the execution
of a call on Process.all. Any exception raised by Process.all
is propagated.
procedure Reverse_Iterate
(Container : in Vector;
Process : not null access procedure (Position : in Cursor))
with Allows_Exit;
Iterates over the
elements in Container as per procedure Iterate, except that elements
are traversed in reverse index order.
function Iterate (Container : in Vector)
return Vector_Iterator_Interfaces.Parallel_Reversible_Iterator'Class
with Post => Tampering_With_Cursors_Prohibited (Container);
Iterate returns
an iterator object (see
5.5.1) that will
generate a value for a loop parameter (see
5.5.2)
designating each node in Container, starting with the first node and
moving the cursor as per the Next function when used as a forward iterator,
and starting with the last node and moving the cursor as per the Previous
function when used as a reverse iterator, and processing all nodes concurrently
when used as a parallel iterator. Tampering with the cursors of Container
is prohibited while the iterator object exists (in particular, in the
sequence_of_statements
of the
loop_statement
whose
iterator_specification
denotes this object). The iterator object needs finalization.
function Iterate (Container : in Vector; Start : in Cursor)
return Vector_Iterator_Interfaces.Reversible_Iterator'Class
with Pre => (Start /= No_Element
or else raise Constraint_Error) and then
(Has_Element (Container, Start)
or else raise Program_Error),
Post => Tampering_With_Cursors_Prohibited (Container);
Iterate returns
a reversible iterator object (see
5.5.1)
that will generate a value for a loop parameter (see
5.5.2)
designating each node in Container, starting with the node designated
by Start and moving the cursor as per the Next function when used as
a forward iterator, or moving the cursor as per the Previous function
when used as a reverse iterator. Tampering with the cursors of Container
is prohibited while the iterator object exists (in particular, in the
sequence_of_statements
of the
loop_statement
whose
iterator_specification
denotes this object). The iterator object needs finalization.
The actual function for the generic formal function
"<" of Generic_Sorting is expected to return the same value
each time it is called with a particular pair of element values. It should
define a strict weak ordering relationship (see
A.18);
it should not modify Container. If the actual for "<" behaves
in some other manner, the behavior of the subprograms of Generic_Sorting
are unspecified. The number of times the subprograms of Generic_Sorting
call "<" is unspecified.
function Is_Sorted (Container : Vector) return Boolean;
Returns True if
the elements are sorted smallest first as determined by the generic formal
"<" operator; otherwise, Is_Sorted returns False. Any exception
raised during evaluation of "<" is propagated.
procedure Sort (Container : in out Vector)
with Pre => not Tampering_With_Cursors_Prohibited (Container)
or else raise Program_Error;
Reorders the elements
of Container such that the elements are sorted smallest first as determined
by the generic formal "<" operator provided. Any exception
raised during evaluation of "<" is propagated.
procedure Merge (Target : in out Vector;
Source : in out Vector)
with Pre => (not Tampering_With_Cursors_Prohibited (Target)
or else raise Program_Error) and then
(not Tampering_With_Cursors_Prohibited (Source)
or else raise Program_Error) and then
(Length (Target) <= Maximum_Length - Length (Source)
or else raise Constraint_Error) and then
((Length (Source) = 0 or else
not Target'Has_Same_Storage (Source))
or else raise Program_Error),
Post => (declare
Result_Length : constant Count_Type :=
Length (Source)'Old + Length (Target)'Old;
begin
(Length (Source) = 0 and then
Length (Target) = Result_Length and then
Capacity (Target) >= Result_Length));
Merge removes elements
from Source and inserts them into Target; afterwards, Target contains
the union of the elements that were initially in Source and Target; Source
is left empty. If Target and Source are initially sorted smallest first,
then Target is ordered smallest first as determined by the generic formal
"<" operator; otherwise, the order of elements in Target
is unspecified. Any exception raised during evaluation of "<"
is propagated.
The nested package Vectors.Stable provides a type
Stable.Vector that represents a
stable vector,
which is one that cannot grow and shrink. Such a vector can be created
by calling the To_Vector or Copy functions, or by establishing a
stabilized
view of an ordinary vector.
The subprograms
of package Containers.Vectors that have a parameter or result of type
Vector are included in the nested package Stable with the same specification,
except that the following are omitted:
Tampering_With_Cursors_Prohibited, Tampering_With_Elements_Prohibited,
Reserve_Capacity, Assign, Move, Insert, Insert_Space, Insert_Vector,
Append, Append_Vector, Prepend, Prepend_Vector, Clear, Delete, Delete_First,
Delete_Last, and Set_Length
The generic package
Generic_Sorting is also included with the same specification, except
that Merge is omitted.
The operations of this package are equivalent
to those for ordinary vectors, except that the calls to Tampering_With_Cursors_Prohibited
and Tampering_With_Elements_Prohibited that occur in preconditions are
replaced by False, and any that occur in postconditions are replaced
by True.
If a stable vector is declared with the Base discriminant
designating a pre-existing ordinary vector, the stable vector represents
a stabilized view of the underlying ordinary vector, and any operation
on the stable vector is reflected on the underlying ordinary vector.
While a stabilized view exists, any operation that tampers with elements
performed on the underlying vector is prohibited. The finalization of
a stable vector that provides such a view removes this restriction on
the underlying ordinary vector (though some other restriction can exist
due to other concurrent iterations or stabilized views).
If a stable vector is declared without specifying
Base, the object is necessarily initialized. The initializing expression
of the stable vector, typically a call on To_Vector or Copy, determines
the Length of the vector. The Length of a stable vector never changes
after initialization.
Bounded (Run-Time) Errors
Reading the value of an empty
element by calling Element, Query_Element, Update_Element, Constant_Reference,
Reference, Swap, Is_Sorted, Sort, Merge, "=", Find, or Reverse_Find
is a bounded error. The implementation may treat the element as having
any normal value (see
13.9.1) of the element
type, or raise Constraint_Error
or Program_Error
before modifying the vector.
Calling Merge in an instance
of Generic_Sorting with either Source or Target not ordered smallest
first using the provided generic formal "<" operator is
a bounded error. Either Program_Error is raised after Target is updated
as described for Merge, or the operation works as defined.
It is a bounded error for
the actual function associated with a generic formal subprogram, when
called as part of an operation of this package, to tamper with elements
of any Vector parameter of the operation. Either Program_Error is raised,
or the operation works as defined on the value of the Vector either prior
to, or subsequent to, some or all of the modifications to the Vector.
It is a bounded error to call
any subprogram declared in the visible part of Containers.Vectors when
the associated container has been finalized. If the operation takes Container
as an
in out parameter, then it raises Constraint_Error or Program_Error.
Otherwise, the operation either proceeds as it would for an empty container,
or it raises Constraint_Error
or Program_Error.
A
Cursor value is
ambiguous if any of the following have occurred
since it was created:
Insert, Insert_Space, Insert_Vector, or Delete
has been called on the vector that contains the element the cursor designates
with an index value (or a cursor designating an element at such an index
value) less than or equal to the index value of the element designated
by the cursor; or
The vector that contains the element it designates
has been passed to the Sort or Merge procedures of an instance of Generic_Sorting,
or to the Reverse_Elements procedure.
It
is a bounded error to call any subprogram other than "=" or
Has_Element declared in Containers.Vectors with an ambiguous (but not
invalid, see below) cursor parameter. Possible results are:
The cursor may be treated as if it were No_Element;
The cursor may designate some element in the vector
(but not necessarily the element that it originally designated);
Constraint_Error may be raised; or
Program_Error may be raised.
Erroneous Execution
A Cursor value is
invalid if any of the following have occurred since it was created:
The vector that contains the element it designates
has been finalized;
The vector that contains the element it designates
has been used as the Target of a call to Assign, or as the target of
an
assignment_statement;
The vector that contains the element it designates
has been used as the Source or Target of a call to Move; or
The element it designates has been deleted or removed
from the vector that previously contained the element.
The result of "=" or Has_Element is unspecified
if it is called with an invalid cursor parameter.
Execution is erroneous if any other subprogram declared in Containers.Vectors
is called with an invalid cursor parameter.
Execution is erroneous if the vector associated
with the result of a call to Reference or Constant_Reference is finalized
before the result object returned by the call to Reference or Constant_Reference
is finalized.
Implementation Requirements
No storage associated with a vector object shall
be lost upon assignment or scope exit.
The execution of an
assignment_statement
for a vector shall have the effect of copying the elements from the source
vector object to the target vector object and changing the length of
the target object to that of the source object.
Implementation Advice
Containers.Vectors should be implemented similarly
to an array. In particular, if the length of a vector is N, then
the worst-case time complexity of Element should
be O(log N);
the worst-case time complexity of Append with Count=1
when N is less than the capacity of the vector should be O(log
N); and
the worst-case time complexity of Prepend with
Count=1 and Delete_First with Count=1 should be O(N log
N).
The worst-case time complexity of a call on procedure
Sort of an instance of Containers.Vectors.Generic_Sorting should be O(N**2),
and the average time complexity should be better than O(N**2).
Containers.Vectors.Generic_Sorting.Sort and Containers.Vectors.Generic_Sorting.Merge
should minimize copying of elements.
Move should not copy elements, and should minimize
copying of internal data structures.
If an exception is propagated from a vector operation,
no storage should be lost, nor any elements removed from a vector unless
specified by the operation.
NOTE 1 All elements of a vector occupy
locations in the internal array. If a sparse container is required, a
Hashed_Map can be used rather than a vector.
NOTE 2 If Index_Type'Base'First =
Index_Type'First an instance of Ada.Containers.Vectors will raise Constraint_Error.
A value below Index_Type'First is required so that an empty vector has
a meaningful value of Last_Index.
Ada 2005 and 2012 Editions sponsored in part by Ada-Europe
