1 ------------------------------------------------------------------------------
3 -- GNAT RUNTIME COMPONENTS --
5 -- S Y S T E M . W I D _ E N U M --
10 -- Copyright (C) 1992-2000 Free Software Foundation, Inc. --
12 -- GNAT is free software; you can redistribute it and/or modify it under --
13 -- terms of the GNU General Public License as published by the Free Soft- --
14 -- ware Foundation; either version 2, or (at your option) any later ver- --
15 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
16 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
17 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
18 -- for more details. You should have received a copy of the GNU General --
19 -- Public License distributed with GNAT; see file COPYING. If not, write --
20 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
21 -- MA 02111-1307, USA. --
23 -- As a special exception, if other files instantiate generics from this --
24 -- unit, or you link this unit with other files to produce an executable, --
25 -- this unit does not by itself cause the resulting executable to be --
26 -- covered by the GNU General Public License. This exception does not --
27 -- however invalidate any other reasons why the executable file might be --
28 -- covered by the GNU Public License. --
30 -- GNAT was originally developed by the GNAT team at New York University. --
31 -- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
33 ------------------------------------------------------------------------------
35 -- This package contains the routine used for Enumeration_Type'Width
37 package System
.Wid_Enum
is
38 pragma Pure
(Wid_Enum
);
40 function Width_Enumeration_8
42 Indexes
: System
.Address
;
45 -- Used to compute Enum'Width where Enum is some enumeration subtype
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 reason that Indexes is passed by address is that the actual type
54 -- is created on the fly by the expander.
56 -- Lo and Hi are the Pos values of the lower and upper bounds of the
57 -- subtype. The result is the value of Width, i.e. the maximum value
58 -- of the length of any enumeration literal in the given range.
60 function Width_Enumeration_16
62 Indexes
: System
.Address
;
65 -- Identical to Width_Enumeration_8 except that it handles types
66 -- using array (0 .. Num) of Natural_16 for the Indexes table.
68 function Width_Enumeration_32
70 Indexes
: System
.Address
;
73 -- Identical to Width_Enumeration_8 except that it handles types
74 -- using array (0 .. Num) of Natural_32 for the Indexes table.