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-- --
-- --
-- S Y S T E M . V A L U E _ N --
-- --
-- S p e c --
-- --
-- Copyright (C) 2021, 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 --
-- --
-- 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 --
-- <>. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
-- This package is used to compute the Value attribute for enumeration types
-- other than those in packages Standard and System. See unit Exp_Imgv for
-- details of the format of constructed image tables.
type Index_Type is range <>;
package System.Value_N is
pragma Preelaborate;
type Hash_Function_Ptr is access function (S : String) return Natural;
function Value_Enumeration
(Names : String;
Indexes : System.Address;
Hash : Hash_Function_Ptr;
Num : Natural;
Str : String)
return Natural with Inline;
-- Used to compute Enum'Value (Str) where Enum is some enumeration type
-- other than those defined in package Standard. Names is a string with
-- a lower bound of 1 containing the characters of all the enumeration
-- literals concatenated together in sequence. Indexes is the address
-- of an array of type array (0 .. N) of Index_Type, where N is the
-- number of enumeration literals in the type. The Indexes values are
-- the starting subscript of each enumeration literal, indexed by Pos
-- values, with an extra entry at the end containing Names'Length + 1.
-- The parameter Hash is a (perfect) hash function for Names and Indexes.
-- The parameter Num is the value N - 1 (i.e. Enum'Pos (Enum'Last)).
-- The reason that Indexes is passed by address is that the actual type
-- is created on the fly by the expander.
-- Str is the argument of the attribute function, and may have leading
-- and trailing spaces, and letters can be upper or lower case or mixed.
-- If the image is found in Names, then the corresponding Pos value is
-- returned. If not, Constraint_Error is raised.
function Valid_Value_Enumeration
(Names : String;
Indexes : System.Address;
Hash : Hash_Function_Ptr;
Num : Natural;
Str : String)
return Boolean with Inline;
-- Returns True if Str is a valid Image of some enumeration literal, False
-- otherwise. That is, returns False if and only if Value_Enumeration would
-- raise Constraint_Error. The parameters have the same meaning as for
-- Value_Enumeration.
end System.Value_N;