comparison gcc/ada/libgnat/s-vallld.ads @ 111:04ced10e8804

gcc 7
author kono
date Fri, 27 Oct 2017 22:46:09 +0900
parents
children 84e7813d76e9
comparison
equal deleted inserted replaced
68:561a7518be6b 111:04ced10e8804
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT COMPILER COMPONENTS --
4 -- --
5 -- S Y S T E M . V A L _ L L D --
6 -- --
7 -- S p e c --
8 -- --
9 -- Copyright (C) 1992-2017, 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 -- As a special exception under Section 7 of GPL version 3, you are granted --
19 -- additional permissions described in the GCC Runtime Library Exception, --
20 -- version 3.1, as published by the Free Software Foundation. --
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 contains routines for scanning decimal values where the size
33 -- of the type is greater than Standard.Integer'Size, for use in Text_IO.
34 -- Decimal_IO, and the Value attribute for such decimal types.
35
36 package System.Val_LLD is
37 pragma Pure;
38
39 function Scan_Long_Long_Decimal
40 (Str : String;
41 Ptr : not null access Integer;
42 Max : Integer;
43 Scale : Integer) return Long_Long_Integer;
44 -- This function scans the string starting at Str (Ptr.all) for a valid
45 -- real literal according to the syntax described in (RM 3.5(43)). The
46 -- substring scanned extends no further than Str (Max). There are three
47 -- cases for the return:
48 --
49 -- If a valid real literal is found after scanning past any initial spaces,
50 -- then Ptr.all is updated past the last character of the literal (but
51 -- trailing spaces are not scanned out). The value returned is the value
52 -- Long_Long_Integer'Integer_Value (decimal-literal-value), using the given
53 -- Scale to determine this value.
54 --
55 -- If no valid real literal is found, then Ptr.all points either to an
56 -- initial non-digit character, or to Max + 1 if the field is all spaces
57 -- and the exception Constraint_Error is raised.
58 --
59 -- If a syntactically valid integer is scanned, but the value is out of
60 -- range, or, in the based case, the base value is out of range or there
61 -- is an out of range digit, then Ptr.all points past the integer, and
62 -- Constraint_Error is raised.
63 --
64 -- Note: these rules correspond to the requirements for leaving the
65 -- pointer positioned in Text_Io.Get
66 --
67 -- Note: if Str is null, i.e. if Max is less than Ptr, then this is a
68 -- special case of an all-blank string, and Ptr is unchanged, and hence
69 -- is greater than Max as required in this case.
70
71 function Value_Long_Long_Decimal
72 (Str : String;
73 Scale : Integer) return Long_Long_Integer;
74 -- Used in computing X'Value (Str) where X is a decimal types whose size
75 -- exceeds Standard.Integer'Size. Str is the string argument of the
76 -- attribute. Constraint_Error is raised if the string is malformed
77 -- or if the value is out of range, otherwise the value returned is the
78 -- value Long_Long_Integer'Integer_Value (decimal-literal-value), using
79 -- the given Scale to determine this value.
80
81 end System.Val_LLD;