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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S Y S T E M . V A L U E _ N --
-- --
-- B o d y --
-- --
-- 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 --
-- <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. --
-- --
------------------------------------------------------------------------------
with Ada.Unchecked_Conversion;
with System.Val_Util; use System.Val_Util;
package body System.Value_N is
function Value_Enumeration_Pos
(Names : String;
Indexes : System.Address;
Hash : Hash_Function_Ptr;
Num : Natural;
Str : String)
return Integer with Pure_Function;
-- Same as Value_Enumeration, except returns negative if Value_Enumeration
-- would raise Constraint_Error.
---------------------------
-- Value_Enumeration_Pos --
---------------------------
function Value_Enumeration_Pos
(Names : String;
Indexes : System.Address;
Hash : Hash_Function_Ptr;
Num : Natural;
Str : String)
return Integer
is
F, L : Integer;
H : Natural;
S : String (Str'Range) := Str;
subtype Names_Index is
Index_Type range Index_Type (Names'First)
.. Index_Type (Names'Last) + 1;
subtype Index is Natural range Natural'First .. Names'Length;
type Index_Table is array (Index) of Names_Index;
type Index_Table_Ptr is access Index_Table;
function To_Index_Table_Ptr is
new Ada.Unchecked_Conversion (System.Address, Index_Table_Ptr);
IndexesT : constant Index_Table_Ptr := To_Index_Table_Ptr (Indexes);
pragma Assert (Num + 1 in IndexesT'Range);
begin
Normalize_String (S, F, L);
declare
Normal : String renames S (F .. L);
begin
-- If we have a valid hash value, do a single lookup
H := (if Hash /= null then Hash.all (Normal) else Natural'Last);
if H /= Natural'Last then
if Names
(Natural (IndexesT (H)) ..
Natural (IndexesT (H + 1)) - 1) = Normal
then
return H;
end if;
-- Otherwise do a linear search
else
for J in 0 .. Num loop
if Names
(Natural (IndexesT (J)) ..
Natural (IndexesT (J + 1)) - 1) = Normal
then
return J;
end if;
end loop;
end if;
end;
return -1;
end Value_Enumeration_Pos;
-----------------------------
-- Valid_Value_Enumeration --
-----------------------------
function Valid_Value_Enumeration
(Names : String;
Indexes : System.Address;
Hash : Hash_Function_Ptr;
Num : Natural;
Str : String)
return Boolean
is
begin
return Value_Enumeration_Pos (Names, Indexes, Hash, Num, Str) >= 0;
end Valid_Value_Enumeration;
-----------------------
-- Value_Enumeration --
-----------------------
function Value_Enumeration
(Names : String;
Indexes : System.Address;
Hash : Hash_Function_Ptr;
Num : Natural;
Str : String)
return Natural
is
Result : constant Integer :=
Value_Enumeration_Pos (Names, Indexes, Hash, Num, Str);
begin
-- The comparison eliminates the need for a range check on return
if Result < 0 then
Bad_Value (Str);
else
return Result;
end if;
end Value_Enumeration;
end System.Value_N;
|
