File : s-valenu.ads
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT COMPILER COMPONENTS --
4 -- --
5 -- S Y S T E M . V A L _ E N U M --
6 -- --
7 -- S p e c --
8 -- --
9 -- Copyright (C) 1992-2009, Free Software Foundation, Inc. --
10 -- --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. --
17 -- --
18 -- --
19 -- --
20 -- --
21 -- --
22 -- You should have received a copy of the GNU General Public License and --
23 -- a copy of the GCC Runtime Library Exception along with this program; --
24 -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
25 -- <http://www.gnu.org/licenses/>. --
26 -- --
27 -- GNAT was originally developed by the GNAT team at New York University. --
28 -- Extensive contributions were provided by Ada Core Technologies Inc. --
29 -- --
30 ------------------------------------------------------------------------------
31
32 -- This package is used to compute the Value attribute for enumeration types
33 -- other than those in packages Standard and System. See unit Exp_Imgv for
34 -- details of the format of constructed image tables.
35
36 package System.Val_Enum is
37 pragma Pure;
38
39 function Value_Enumeration_8
40 (Names : String;
41 Indexes : System.Address;
42 Num : Natural;
43 Str : String)
44 return Natural;
45 -- Used to compute Enum'Value (Str) where Enum is some enumeration type
46 -- other than those defined in package Standard. Names is a string with
47 -- a lower bound of 1 containing the characters of all the enumeration
48 -- literals concatenated together in sequence. Indexes is the address
49 -- of an array of type array (0 .. N) of Natural_8, where N is the
50 -- number of enumeration literals in the type. The Indexes values are
51 -- the starting subscript of each enumeration literal, indexed by Pos
52 -- values, with an extra entry at the end containing Names'Length + 1.
53 -- The parameter Num is the value N - 1 (i.e. Enum'Pos (Enum'Last)).
54 -- The reason that Indexes is passed by address is that the actual type
55 -- is created on the fly by the expander.
56 --
57 -- Str is the argument of the attribute function, and may have leading
58 -- and trailing spaces, and letters can be upper or lower case or mixed.
59 -- If the image is found in Names, then the corresponding Pos value is
60 -- returned. If not, Constraint_Error is raised.
61
62 function Value_Enumeration_16
63 (Names : String;
64 Indexes : System.Address;
65 Num : Natural;
66 Str : String)
67 return Natural;
68 -- Identical to Value_Enumeration_8 except that it handles types
69 -- using array (0 .. Num) of Natural_16 for the Indexes table.
70
71 function Value_Enumeration_32
72 (Names : String;
73 Indexes : System.Address;
74 Num : Natural;
75 Str : String)
76 return Natural;
77 -- Identical to Value_Enumeration_8 except that it handles types
78 -- using array (0 .. Num) of Natural_32 for the Indexes table.
79
80 end System.Val_Enum;