1------------------------------------------------------------------------------ 2-- -- 3-- GNAT RUN-TIME COMPONENTS -- 4-- -- 5-- S Y S T E M . V A L _ I N T -- 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 signed Integer values for use 33-- in Text_IO.Integer_IO, and the Value attribute. 34 35package System.Val_Int is 36 pragma Pure; 37 38 function Scan_Integer 39 (Str : String; 40 Ptr : not null access Integer; 41 Max : Integer) return Integer; 42 -- This function scans the string starting at Str (Ptr.all) for a valid 43 -- integer according to the syntax described in (RM 3.5(43)). The substring 44 -- scanned extends no further than Str (Max). There are three cases for the 45 -- return: 46 -- 47 -- If a valid integer is found after scanning past any initial spaces, then 48 -- Ptr.all is updated past the last character of the integer (but trailing 49 -- spaces are not scanned out). 50 -- 51 -- If no valid integer is found, then Ptr.all points either to an initial 52 -- non-digit character, or to Max + 1 if the field is all spaces and the 53 -- exception Constraint_Error is raised. 54 -- 55 -- If a syntactically valid integer is scanned, but the value is out of 56 -- range, or, in the based case, the base value is out of range or there 57 -- is an out of range digit, then Ptr.all points past the integer, and 58 -- Constraint_Error is raised. 59 -- 60 -- Note: these rules correspond to the requirements for leaving the pointer 61 -- positioned in Text_Io.Get 62 -- 63 -- Note: if Str is null, i.e. if Max is less than Ptr, then this is a 64 -- special case of an all-blank string, and Ptr is unchanged, and hence 65 -- is greater than Max as required in this case. 66 67 function Value_Integer (Str : String) return Integer; 68 -- Used in computing X'Value (Str) where X is a signed integer type whose 69 -- base range does not exceed the base range of Integer. Str is the string 70 -- argument of the attribute. Constraint_Error is raised if the string is 71 -- malformed, or if the value is out of range. 72 73end System.Val_Int; 74