1-- Copyright 1994 Grady Booch 2-- Copyright 1994-1997 David Weller 3-- Copyright 1998-2014 Simon Wright <simon@pushface.org> 4 5-- This package is free software; you can redistribute it and/or 6-- modify it under terms of the GNU General Public License as 7-- published by the Free Software Foundation; either version 2, or 8-- (at your option) any later version. This package is distributed in 9-- the hope that it will be useful, but WITHOUT ANY WARRANTY; without 10-- even the implied warranty of MERCHANTABILITY or FITNESS FOR A 11-- PARTICULAR PURPOSE. See the GNU General Public License for more 12-- details. You should have received a copy of the GNU General Public 13-- License distributed with this package; see file COPYING. If not, 14-- write to the Free Software Foundation, 59 Temple Place - Suite 15-- 330, Boston, MA 02111-1307, USA. 16 17-- As a special exception, if other files instantiate generics from 18-- this unit, or you link this unit with other files to produce an 19-- executable, this unit does not by itself cause the resulting 20-- executable to be covered by the GNU General Public License. This 21-- exception does not however invalidate any other reasons why the 22-- executable file might be covered by the GNU Public License. 23 24with System; 25 26package body BC.Containers.Stacks is 27 28 procedure Process_Top (S : in out Abstract_Stack'Class) is 29 begin 30 Process (Item_At (S, 1).all); 31 end Process_Top; 32 33 function Are_Equal (Left, Right : Abstract_Stack'Class) return Boolean is 34 begin 35 if System."=" (Left'Address, Right'Address) then 36 return True; 37 end if; 38 if Depth (Left) /= Depth (Right) then 39 return False; 40 end if; 41 declare 42 Left_Iter : Iterator'Class := New_Iterator (Left); 43 Right_Iter : Iterator'Class := New_Iterator (Right); 44 begin 45 while not Is_Done (Left_Iter) and then 46 not Is_Done (Right_Iter) loop 47 if Current_Item (Left_Iter) /= Current_Item (Right_Iter) then 48 return False; 49 end if; 50 Next (Left_Iter); 51 Next (Right_Iter); 52 end loop; 53 return True; 54 end; 55 end Are_Equal; 56 57 procedure Copy (From : Abstract_Stack'Class; 58 To : in out Abstract_Stack'Class) is 59 Iter : Iterator'Class := New_Iterator (From); 60 begin 61 if System."/=" (From'Address, To'Address) then 62 Clear (To); 63 Reset (Iter); 64 while not Is_Done (Iter) loop 65 Add (To, Current_Item (Iter)); 66 Next (Iter); 67 end loop; 68 end if; 69 end Copy; 70 71 function Available (S : in Abstract_Stack) return Natural is 72 pragma Warnings (Off, S); 73 begin 74 return Natural'Last; 75 end Available; 76 77 -- Subprograms to be overridden 78 79 procedure Add (S : in out Abstract_Stack; Elem : Item) is 80 begin 81 raise Should_Have_Been_Overridden; 82 end Add; 83 84 procedure Remove (S : in out Abstract_Stack; From : Positive) is 85 begin 86 raise Should_Have_Been_Overridden; 87 end Remove; 88 89 -- Iterators 90 91 procedure Reset (It : in out Stack_Iterator) is 92 S : Abstract_Stack'Class 93 renames Abstract_Stack'Class (It.For_The_Container.all); 94 begin 95 if Depth (S) = 0 then 96 It.Index := 0; 97 else 98 It.Index := 1; 99 end if; 100 end Reset; 101 102 procedure Next (It : in out Stack_Iterator) is 103 begin 104 It.Index := It.Index + 1; 105 end Next; 106 107 function Is_Done (It : Stack_Iterator) return Boolean is 108 S : Abstract_Stack'Class 109 renames Abstract_Stack'Class (It.For_The_Container.all); 110 begin 111 return It.Index = 0 or else It.Index > Depth (S); 112 end Is_Done; 113 114 function Current_Item (It : Stack_Iterator) return Item is 115 begin 116 if Is_Done (It) then 117 raise BC.Not_Found; 118 end if; 119 return Item_At (It.For_The_Container.all, It.Index).all; 120 end Current_Item; 121 122 function Current_Item_Ptr (It : Stack_Iterator) return Item_Ptr is 123 begin 124 if Is_Done (It) then 125 raise BC.Not_Found; 126 end if; 127 return Item_At (It.For_The_Container.all, It.Index); 128 end Current_Item_Ptr; 129 130 procedure Delete_Item_At (It : in out Stack_Iterator) is 131 S : Abstract_Stack'Class 132 renames Abstract_Stack'Class (It.For_The_Container.all); 133 begin 134 if Is_Done (It) then 135 raise BC.Not_Found; 136 end if; 137 Remove (S, It.Index); 138 end Delete_Item_At; 139 140end BC.Containers.Stacks; 141