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------------------------------------------------------------------------------
-- --
-- GNAT LIBRARY COMPONENTS --
-- --
-- ADA.CONTAINERS.FUNCTIONAL_BASE --
-- --
-- B o d y --
-- --
-- Copyright (C) 2016-2021, Free Software Foundation, Inc. --
-- --
-- This specification is derived from the Ada Reference Manual for use with --
-- GNAT. The copyright notice above, and the license provisions that follow --
-- apply solely to the contents of the part following the private keyword. --
-- --
-- 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/>. --
------------------------------------------------------------------------------
pragma Ada_2012;
with Ada.Unchecked_Deallocation;
package body Ada.Containers.Functional_Base with SPARK_Mode => Off is
function To_Count (Idx : Extended_Index) return Count_Type is
(Count_Type
(Extended_Index'Pos (Idx) -
Extended_Index'Pos (Extended_Index'First)));
function To_Index (Position : Count_Type) return Extended_Index is
(Extended_Index'Val
(Position + Extended_Index'Pos (Extended_Index'First)));
-- Conversion functions between Index_Type and Count_Type
function Find (C : Container; E : access Element_Type) return Count_Type;
-- Search a container C for an element equal to E.all, returning the
-- position in the underlying array.
procedure Resize (Base : Array_Base_Access);
-- Resize the underlying array if needed so that it can contain one more
-- element.
---------
-- "=" --
---------
function "=" (C1 : Container; C2 : Container) return Boolean is
begin
if C1.Length /= C2.Length then
return False;
end if;
for I in 1 .. C1.Length loop
if C1.Base.Elements (I).all /= C2.Base.Elements (I).all then
return False;
end if;
end loop;
return True;
end "=";
----------
-- "<=" --
----------
function "<=" (C1 : Container; C2 : Container) return Boolean is
begin
for I in 1 .. C1.Length loop
if Find (C2, C1.Base.Elements (I)) = 0 then
return False;
end if;
end loop;
return True;
end "<=";
---------
-- Add --
---------
function Add
(C : Container;
I : Index_Type;
E : Element_Type) return Container
is
begin
if To_Count (I) = C.Length + 1 and then C.Length = C.Base.Max_Length then
Resize (C.Base);
C.Base.Max_Length := C.Base.Max_Length + 1;
C.Base.Elements (C.Base.Max_Length) := new Element_Type'(E);
return Container'(Length => C.Base.Max_Length, Base => C.Base);
else
declare
A : constant Array_Base_Access := Content_Init (C.Length);
P : Count_Type := 0;
begin
A.Max_Length := C.Length + 1;
for J in 1 .. C.Length + 1 loop
if J /= To_Count (I) then
P := P + 1;
A.Elements (J) := C.Base.Elements (P);
else
A.Elements (J) := new Element_Type'(E);
end if;
end loop;
return Container'(Length => A.Max_Length,
Base => A);
end;
end if;
end Add;
------------------
-- Content_Init --
------------------
function Content_Init (L : Count_Type := 0) return Array_Base_Access
is
Max_Init : constant Count_Type := 100;
Size : constant Count_Type :=
(if L < Count_Type'Last - Max_Init then L + Max_Init
else Count_Type'Last);
Elements : constant Element_Array_Access :=
new Element_Array'(1 .. Size => <>);
begin
return new Array_Base'(Max_Length => 0, Elements => Elements);
end Content_Init;
----------
-- Find --
----------
function Find (C : Container; E : access Element_Type) return Count_Type is
begin
for I in 1 .. C.Length loop
if C.Base.Elements (I).all = E.all then
return I;
end if;
end loop;
return 0;
end Find;
function Find (C : Container; E : Element_Type) return Extended_Index is
(To_Index (Find (C, E'Unrestricted_Access)));
---------
-- Get --
---------
function Get (C : Container; I : Index_Type) return Element_Type is
(C.Base.Elements (To_Count (I)).all);
------------------
-- Intersection --
------------------
function Intersection (C1 : Container; C2 : Container) return Container is
L : constant Count_Type := Num_Overlaps (C1, C2);
A : constant Array_Base_Access := Content_Init (L);
P : Count_Type := 0;
begin
A.Max_Length := L;
for I in 1 .. C1.Length loop
if Find (C2, C1.Base.Elements (I)) > 0 then
P := P + 1;
A.Elements (P) := C1.Base.Elements (I);
end if;
end loop;
return Container'(Length => P, Base => A);
end Intersection;
------------
-- Length --
------------
function Length (C : Container) return Count_Type is (C.Length);
---------------------
-- Num_Overlaps --
---------------------
function Num_Overlaps (C1 : Container; C2 : Container) return Count_Type is
P : Count_Type := 0;
begin
for I in 1 .. C1.Length loop
if Find (C2, C1.Base.Elements (I)) > 0 then
P := P + 1;
end if;
end loop;
return P;
end Num_Overlaps;
------------
-- Remove --
------------
function Remove (C : Container; I : Index_Type) return Container is
begin
if To_Count (I) = C.Length then
return Container'(Length => C.Length - 1, Base => C.Base);
else
declare
A : constant Array_Base_Access := Content_Init (C.Length - 1);
P : Count_Type := 0;
begin
A.Max_Length := C.Length - 1;
for J in 1 .. C.Length loop
if J /= To_Count (I) then
P := P + 1;
A.Elements (P) := C.Base.Elements (J);
end if;
end loop;
return Container'(Length => C.Length - 1, Base => A);
end;
end if;
end Remove;
------------
-- Resize --
------------
procedure Resize (Base : Array_Base_Access) is
begin
if Base.Max_Length < Base.Elements'Length then
return;
end if;
pragma Assert (Base.Max_Length = Base.Elements'Length);
if Base.Max_Length = Count_Type'Last then
raise Constraint_Error;
end if;
declare
procedure Finalize is new Ada.Unchecked_Deallocation
(Object => Element_Array,
Name => Element_Array_Access_Base);
New_Length : constant Positive_Count_Type :=
(if Base.Max_Length > Count_Type'Last / 2 then Count_Type'Last
else 2 * Base.Max_Length);
Elements : constant Element_Array_Access :=
new Element_Array (1 .. New_Length);
Old_Elmts : Element_Array_Access_Base := Base.Elements;
begin
Elements (1 .. Base.Max_Length) := Base.Elements.all;
Base.Elements := Elements;
Finalize (Old_Elmts);
end;
end Resize;
---------
-- Set --
---------
function Set
(C : Container;
I : Index_Type;
E : Element_Type) return Container
is
Result : constant Container :=
Container'(Length => C.Length,
Base => Content_Init (C.Length));
begin
Result.Base.Max_Length := C.Length;
Result.Base.Elements (1 .. C.Length) := C.Base.Elements (1 .. C.Length);
Result.Base.Elements (To_Count (I)) := new Element_Type'(E);
return Result;
end Set;
-----------
-- Union --
-----------
function Union (C1 : Container; C2 : Container) return Container is
N : constant Count_Type := Num_Overlaps (C1, C2);
begin
-- if C2 is completely included in C1 then return C1
if N = Length (C2) then
return C1;
end if;
-- else loop through C2 to find the remaining elements
declare
L : constant Count_Type := Length (C1) - N + Length (C2);
A : constant Array_Base_Access := Content_Init (L);
P : Count_Type := Length (C1);
begin
A.Max_Length := L;
A.Elements (1 .. C1.Length) := C1.Base.Elements (1 .. C1.Length);
for I in 1 .. C2.Length loop
if Find (C1, C2.Base.Elements (I)) = 0 then
P := P + 1;
A.Elements (P) := C2.Base.Elements (I);
end if;
end loop;
return Container'(Length => L, Base => A);
end;
end Union;
end Ada.Containers.Functional_Base;