1 ------------------------------------------------------------------------------
3 -- GNAT LIBRARY COMPONENTS --
5 -- A D A . C O N T A I N E R S . F O R M A L _ V E C T O R S --
9 -- Copyright (C) 2004-2015, Free Software Foundation, Inc. --
11 -- This specification is derived from the Ada Reference Manual for use with --
12 -- GNAT. The copyright notice above, and the license provisions that follow --
13 -- apply solely to the contents of the part following the private keyword. --
15 -- GNAT is free software; you can redistribute it and/or modify it under --
16 -- terms of the GNU General Public License as published by the Free Soft- --
17 -- ware Foundation; either version 3, or (at your option) any later ver- --
18 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
19 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
20 -- or FITNESS FOR A PARTICULAR PURPOSE. --
22 -- As a special exception under Section 7 of GPL version 3, you are granted --
23 -- additional permissions described in the GCC Runtime Library Exception, --
24 -- version 3.1, as published by the Free Software Foundation. --
26 -- You should have received a copy of the GNU General Public License and --
27 -- a copy of the GCC Runtime Library Exception along with this program; --
28 -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
29 -- <http://www.gnu.org/licenses/>. --
30 ------------------------------------------------------------------------------
32 -- This spec is derived from package Ada.Containers.Bounded_Vectors in the Ada
33 -- 2012 RM. The modifications are meant to facilitate formal proofs by making
34 -- it easier to express properties, and by making the specification of this
35 -- unit compatible with SPARK 2014. Note that the API of this unit may be
36 -- subject to incompatible changes as SPARK 2014 evolves.
39 type Index_Type is range <>;
40 type Element_Type is private;
42 with function "=" (Left, Right : Element_Type) return Boolean is <>;
44 Bounded : Boolean := True;
45 -- If True, the containers are bounded; the initial capacity is the maximum
46 -- size, and heap allocation will be avoided. If False, the containers can
47 -- grow via heap allocation.
49 package Ada.Containers.Formal_Vectors with
52 pragma Annotate (GNATprove, External_Axiomatization);
54 subtype Extended_Index is Index_Type'Base
55 range Index_Type'First - 1 ..
56 Index_Type'Min (Index_Type'Base'Last - 1, Index_Type'Last) + 1;
58 No_Index : constant Extended_Index := Extended_Index'First;
60 subtype Capacity_Range is
61 Count_Type range 0 .. Count_Type (Index_Type'Last - Index_Type'First + 1);
63 type Vector (Capacity : Capacity_Range) is limited private with
64 Default_Initial_Condition => Is_Empty (Vector);
65 -- In the bounded case, Capacity is the capacity of the container, which
66 -- never changes. In the unbounded case, Capacity is the initial capacity
67 -- of the container, and operations such as Reserve_Capacity and Append can
68 -- increase the capacity. The capacity never shrinks, except in the case of
71 -- Note that all objects of type Vector are constrained, including in the
72 -- unbounded case; you can't assign from one object to another if the
73 -- Capacity is different.
75 function Empty_Vector return Vector;
77 function "=" (Left, Right : Vector) return Boolean with
81 (New_Item : Element_Type;
82 Length : Capacity_Range) return Vector
86 function Capacity (Container : Vector) return Capacity_Range with
88 Post => Capacity'Result >= Container.Capacity;
90 procedure Reserve_Capacity
91 (Container : in out Vector;
92 Capacity : Capacity_Range)
95 Pre => (if Bounded then Capacity <= Container.Capacity);
97 function Length (Container : Vector) return Capacity_Range with
100 function Is_Empty (Container : Vector) return Boolean with
103 procedure Clear (Container : in out Vector) with
105 -- Note that this reclaims storage in the unbounded case. You need to call
106 -- this before a container goes out of scope in order to avoid storage
107 -- leaks. In addition, "X := ..." can leak unless you Clear(X) first.
109 procedure Assign (Target : in out Vector; Source : Vector) with
111 Pre => (if Bounded then Length (Source) <= Target.Capacity);
115 Capacity : Capacity_Range := 0) return Vector
118 Pre => (if Bounded then (Capacity = 0 or Length (Source) <= Capacity));
122 Index : Index_Type) return Element_Type
125 Pre => Index in First_Index (Container) .. Last_Index (Container);
127 procedure Replace_Element
128 (Container : in out Vector;
130 New_Item : Element_Type)
133 Pre => Index in First_Index (Container) .. Last_Index (Container);
136 (Container : in out Vector;
140 Pre => (if Bounded then
141 Length (Container) + Length (New_Item) <= Container.Capacity);
144 (Container : in out Vector;
145 New_Item : Element_Type)
148 Pre => (if Bounded then
149 Length (Container) < Container.Capacity);
151 procedure Delete_Last
152 (Container : in out Vector)
156 procedure Reverse_Elements (Container : in out Vector) with
159 procedure Swap (Container : in out Vector; I, J : Index_Type) with
161 Pre => I in First_Index (Container) .. Last_Index (Container)
162 and then J in First_Index (Container) .. Last_Index (Container);
164 function First_Index (Container : Vector) return Index_Type with
167 function First_Element (Container : Vector) return Element_Type with
169 Pre => not Is_Empty (Container);
171 function Last_Index (Container : Vector) return Extended_Index with
174 function Last_Element (Container : Vector) return Element_Type with
176 Pre => not Is_Empty (Container);
181 Index : Index_Type := Index_Type'First) return Extended_Index
185 function Reverse_Find_Index
188 Index : Index_Type := Index_Type'Last) return Extended_Index
194 Item : Element_Type) return Boolean
200 Position : Extended_Index) return Boolean
205 with function "<" (Left, Right : Element_Type) return Boolean is <>;
206 package Generic_Sorting is
208 function Is_Sorted (Container : Vector) return Boolean with
211 procedure Sort (Container : in out Vector) with
216 function First_To_Previous
218 Current : Index_Type) return Vector
222 Pre => Current in First_Index (Container) .. Last_Index (Container);
224 function Current_To_Last
226 Current : Index_Type) return Vector
230 Pre => Current in First_Index (Container) .. Last_Index (Container);
231 -- First_To_Previous returns a container containing all elements preceding
232 -- Current (excluded) in Container. Current_To_Last returns a container
233 -- containing all elements following Current (included) in Container.
234 -- These two new functions can be used to express invariant properties in
235 -- loops which iterate over containers. First_To_Previous returns the part
236 -- of the container already scanned and Current_To_Last the part not
240 pragma SPARK_Mode (Off);
242 pragma Inline (First_Index);
243 pragma Inline (Last_Index);
244 pragma Inline (Element);
245 pragma Inline (First_Element);
246 pragma Inline (Last_Element);
247 pragma Inline (Replace_Element);
248 pragma Inline (Contains);
250 subtype Array_Index is Capacity_Range range 1 .. Capacity_Range'Last;
251 type Elements_Array is array (Array_Index range <>) of Element_Type;
252 function "=" (L, R : Elements_Array) return Boolean is abstract;
254 type Elements_Array_Ptr is access all Elements_Array;
256 type Vector (Capacity : Capacity_Range) is limited record
257 -- In the bounded case, the elements are stored in Elements. In the
258 -- unbounded case, the elements are initially stored in Elements, until
259 -- we run out of room, then we switch to Elements_Ptr.
260 Last : Extended_Index := No_Index;
261 Elements_Ptr : Elements_Array_Ptr := null;
262 Elements : aliased Elements_Array (1 .. Capacity);
265 -- The primary reason Vector is limited is that in the unbounded case, once
266 -- Elements_Ptr is in use, assignment statements won't work. "X := Y;" will
267 -- cause X and Y to share state; that is, X.Elements_Ptr = Y.Elements_Ptr,
268 -- so for example "Append (X, ...);" will modify BOTH X and Y. That would
269 -- allow SPARK to "prove" things that are false. We could fix that by
270 -- making Vector a controlled type, and override Adjust to make a deep
271 -- copy, but finalization is not allowed in SPARK.
273 -- Note that (unfortunately) this means that 'Old and 'Loop_Entry are not
274 -- allowed on Vectors.
276 function Empty_Vector return Vector is
277 ((Capacity => 0, others => <>));
279 end Ada.Containers.Formal_Vectors;