------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- S Y S T E M . V A L U E _ N -- -- -- -- S p e c -- -- -- -- Copyright (C) 2021-2022, 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 -- -- . -- -- -- -- 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. generic 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;