1------------------------------------------------------------------------------ 2-- -- 3-- GNAT COMPILER COMPONENTS -- 4-- -- 5-- S Y S T E M . V A L _ U N S -- 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-- 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 modular Unsigned 33-- values for use in Text_IO.Modular_IO, and the Value attribute. 34 35with System.Unsigned_Types; 36 37package System.Val_Uns is 38 pragma Pure; 39 40 function Scan_Raw_Unsigned 41 (Str : String; 42 Ptr : not null access Integer; 43 Max : Integer) return System.Unsigned_Types.Unsigned; 44 -- This function scans the string starting at Str (Ptr.all) for a valid 45 -- integer according to the syntax described in (RM 3.5(43)). The substring 46 -- scanned extends no further than Str (Max). Note: this does not scan 47 -- leading or trailing blanks, nor leading sign. 48 -- 49 -- There are three cases for the return: 50 -- 51 -- If a valid integer is found, then Ptr.all is updated past the last 52 -- character of the integer. 53 -- 54 -- If no valid integer is found, then Ptr.all points either to an initial 55 -- non-digit character, or to Max + 1 if the field is all spaces and the 56 -- exception Constraint_Error is raised. 57 -- 58 -- If a syntactically valid integer is scanned, but the value is out of 59 -- range, or, in the based case, the base value is out of range or there 60 -- is an out of range digit, then Ptr.all points past the integer, and 61 -- Constraint_Error is raised. 62 -- 63 -- Note: these rules correspond to the requirements for leaving the pointer 64 -- positioned in Text_IO.Get 65 -- 66 -- Note: if Str is empty, i.e. if Max is less than Ptr, then this is a 67 -- special case of an all-blank string, and Ptr is unchanged, and hence 68 -- is greater than Max as required in this case. 69 70 function Scan_Unsigned 71 (Str : String; 72 Ptr : not null access Integer; 73 Max : Integer) return System.Unsigned_Types.Unsigned; 74 -- Same as Scan_Raw_Unsigned, except scans optional leading 75 -- blanks, and an optional leading plus sign. 76 -- Note: if a minus sign is present, Constraint_Error will be raised. 77 -- Note: trailing blanks are not scanned. 78 79 function Value_Unsigned 80 (Str : String) return System.Unsigned_Types.Unsigned; 81 -- Used in computing X'Value (Str) where X is a modular integer type whose 82 -- modulus does not exceed the range of System.Unsigned_Types.Unsigned. Str 83 -- is the string argument of the attribute. Constraint_Error is raised if 84 -- the string is malformed, or if the value is out of range. 85 86end System.Val_Uns; 87