1------------------------------------------------------------------------------ 2-- -- 3-- GNAT COMPILER COMPONENTS -- 4-- -- 5-- S Y S T E M . V A L _ R E A L -- 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 32package System.Val_Real is 33 pragma Pure; 34 35 function Scan_Real 36 (Str : String; 37 Ptr : not null access Integer; 38 Max : Integer) return Long_Long_Float; 39 -- This function scans the string starting at Str (Ptr.all) for a valid 40 -- real literal according to the syntax described in (RM 3.5(43)). The 41 -- substring scanned extends no further than Str (Max). There are three 42 -- cases for the return: 43 -- 44 -- If a valid real is found after scanning past any initial spaces, then 45 -- Ptr.all is updated past the last character of the real (but trailing 46 -- spaces are not scanned out). 47 -- 48 -- If no valid real is found, then Ptr.all points either to an initial 49 -- non-blank character, or to Max + 1 if the field is all spaces and the 50 -- exception Constraint_Error is raised. 51 -- 52 -- If a syntactically valid real is scanned, but the value is out of 53 -- range, or, in the based case, the base value is out of range or there 54 -- is an out of range digit, then Ptr.all points past the real literal, 55 -- and Constraint_Error is raised. 56 -- 57 -- Note: these rules correspond to the requirements for leaving the 58 -- pointer positioned in Text_Io.Get 59 -- 60 -- Note: if Str is null, i.e. if Max is less than Ptr, then this is a 61 -- special case of an all-blank string, and Ptr is unchanged, and hence 62 -- is greater than Max as required in this case. 63 64 function Value_Real (Str : String) return Long_Long_Float; 65 -- Used in computing X'Value (Str) where X is a floating-point type or an 66 -- ordinary fixed-point type. Str is the string argument of the attribute. 67 -- Constraint_Error is raised if the string is malformed, or if the value 68 -- out of range of Long_Long_Float. 69 70end System.Val_Real; 71