------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- S Y S T E M . V A L _ D E C -- -- -- -- S p e c -- -- -- -- Copyright (C) 1992-2005 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, 51 Franklin Street, Fifth Floor, -- -- Boston, MA 02110-1301, 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 decimal values where the size -- of the type is no greater than Standard.Integer'Size, for use in Text_IO. -- Decimal_IO, and the Value attribute for such decimal types. package System.Val_Dec is pragma Pure; function Scan_Decimal (Str : String; Ptr : access Integer; Max : Integer; Scale : Integer) return Integer; -- This function scans the string starting at Str (Ptr.all) for a valid -- real literal 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 real literal is found after scanning past any initial spaces, -- then Ptr.all is updated past the last character of the literal (but -- trailing spaces are not scanned out). The value returned is the value -- Integer'Integer_Value (decimal-literal-value), using the given Scale -- to determine this value. -- -- If no valid real literal 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_Decimal (Str : String; Scale : Integer) return Integer; -- Used in computing X'Value (Str) where X is a decimal types whose size -- does not exceed Standard.Integer'Size. 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, otherwise the value returned is the -- value Integer'Integer_Value (decimal-literal-value), using the given -- Scale to determine this value. end System.Val_Dec;