------------------------------------------------------------------------------ -- -- -- GNAT RUNTIME COMPONENTS -- -- -- -- S Y S T E M . V A L _ I N T -- -- -- -- S p e c -- -- -- -- Copyright (C) 1992,1993,1994,1995,1996 Free Software Foundation, Inc. -- -- -- -- GNAT is free software; you can redistribute it and/or modify it under -- -- terms of the GNU General Public License as published by the Free Soft- -- -- ware Foundation; either version 2, or (at your option) any later ver- -- -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- -- for more details. You should have received a copy of the GNU General -- -- Public License distributed with GNAT; see file COPYING. If not, write -- -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, -- -- MA 02111-1307, USA. -- -- -- -- As a special exception, if other files instantiate generics from this -- -- unit, or you link this unit with other files to produce an executable, -- -- this unit does not by itself cause the resulting executable to be -- -- covered by the GNU General Public License. This exception does not -- -- however invalidate any other reasons why the executable file might be -- -- covered by the GNU Public License. -- -- -- -- GNAT was originally developed by the GNAT team at New York University. -- -- Extensive contributions were provided by Ada Core Technologies Inc. -- -- -- ------------------------------------------------------------------------------ -- This package contains routines for scanning signed Integer values for use -- in Text_IO.Integer_IO, and the Value attribute. package System.Val_Int is pragma Pure (Val_Int); function Scan_Integer (Str : String; Ptr : access Integer; Max : Integer) return Integer; -- This function scans the string starting at Str (Ptr.all) for a valid -- integer according to the syntax described in (RM 3.5(43)). The substring -- scanned extends no further than Str (Max). There are three cases for the -- return: -- -- If a valid integer is found after scanning past any initial spaces, then -- Ptr.all is updated past the last character of the integer (but trailing -- spaces are not scanned out). -- -- If no valid integer is found, then Ptr.all points either to an initial -- non-digit character, or to Max + 1 if the field is all spaces and the -- exception Constraint_Error is raised. -- -- If a syntactically valid integer is scanned, but the value is out of -- range, or, in the based case, the base value is out of range or there -- is an out of range digit, then Ptr.all points past the integer, and -- Constraint_Error is raised. -- -- Note: these rules correspond to the requirements for leaving the pointer -- positioned in Text_Io.Get -- -- Note: if Str is null, i.e. if Max is less than Ptr, then this is a -- special case of an all-blank string, and Ptr is unchanged, and hence -- is greater than Max as required in this case. function Value_Integer (Str : String) return Integer; -- Used in computing X'Value (Str) where X is a signed integer type whose -- base range does not exceed the base range of Integer. Str is the string -- argument of the attribute. Constraint_Error is raised if the string is -- malformed, or if the value is out of range. end System.Val_Int;