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------------------------------------------------------------------------------
-- --
-- GNAT RUN-TIME COMPONENTS --
-- --
-- S Y S T E M . I M A G E _ U --
-- --
-- S p e c --
-- --
-- Copyright (C) 1992-2023, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 3, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. --
-- --
-- As a special exception under Section 7 of GPL version 3, you are granted --
-- additional permissions described in the GCC Runtime Library Exception, --
-- version 3.1, as published by the Free Software Foundation. --
-- --
-- You should have received a copy of the GNU General Public License and --
-- a copy of the GCC Runtime Library Exception along with this program; --
-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
-- <http://www.gnu.org/licenses/>. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
-- This package contains the routines for supporting the Image attribute for
-- modular integer types, and also for conversion operations required in
-- Text_IO.Modular_IO for such types.
-- Preconditions in this unit are meant for analysis only, not for run-time
-- checking, so that the expected exceptions are raised. This is enforced by
-- setting the corresponding assertion policy to Ignore. Postconditions and
-- contract cases should not be executed at runtime as well, in order not to
-- slow down the execution of these functions.
pragma Assertion_Policy (Pre => Ignore,
Post => Ignore,
Contract_Cases => Ignore,
Ghost => Ignore,
Subprogram_Variant => Ignore);
with System.Value_U_Spec;
generic
type Uns is mod <>;
-- Additional parameters for ghost subprograms used inside contracts
with package U_Spec is new System.Value_U_Spec (Uns => Uns) with Ghost;
package System.Image_U is
use all type U_Spec.Uns_Option;
Unsigned_Width_Ghost : constant Natural := U_Spec.Max_Log10 + 2 with Ghost;
procedure Image_Unsigned
(V : Uns;
S : in out String;
P : out Natural)
with
Pre => S'First = 1
and then S'Last < Integer'Last
and then S'Last >= Unsigned_Width_Ghost,
Post => P in S'Range
and then U_Spec.Is_Value_Unsigned_Ghost (S (1 .. P), V);
pragma Inline (Image_Unsigned);
-- Computes Uns'Image (V) and stores the result in S (1 .. P) setting
-- the resulting value of P. The caller guarantees that S is long enough to
-- hold the result, and that S'First is 1.
procedure Set_Image_Unsigned
(V : Uns;
S : in out String;
P : in out Natural)
with
Pre => P < Integer'Last
and then S'Last < Integer'Last
and then S'First <= P + 1
and then S'First <= S'Last
and then P <= S'Last - Unsigned_Width_Ghost + 1,
Post => S (S'First .. P'Old) = S'Old (S'First .. P'Old)
and then P in P'Old + 1 .. S'Last
and then U_Spec.Only_Decimal_Ghost (S, From => P'Old + 1, To => P)
and then U_Spec.Scan_Based_Number_Ghost
(S, From => P'Old + 1, To => P)
= U_Spec.Wrap_Option (V);
-- Stores the image of V in S starting at S (P + 1), P is updated to point
-- to the last character stored. The value stored is identical to the value
-- of Uns'Image (V) except that no leading space is stored. The caller
-- guarantees that S is long enough to hold the result. S need not have a
-- lower bound of 1.
end System.Image_U;
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