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Diffstat (limited to 'gcc/ada/s-valuns.ads')
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1 files changed, 83 insertions, 0 deletions
diff --git a/gcc/ada/s-valuns.ads b/gcc/ada/s-valuns.ads new file mode 100644 index 00000000000..cc732815f3f --- /dev/null +++ b/gcc/ada/s-valuns.ads @@ -0,0 +1,83 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT COMPILER COMPONENTS -- +-- -- +-- S Y S T E M . V A L _ U N S -- +-- -- +-- S p e c -- +-- -- +-- $Revision: 1.9 $ -- +-- -- +-- 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. -- +-- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). -- +-- -- +------------------------------------------------------------------------------ + +-- This package contains routines for scanning modular Unsigned +-- values for use in Text_IO.Modular, and the Value attribute. + +with System.Unsigned_Types; + +package System.Val_Uns is +pragma Pure (Val_Uns); + + function Scan_Unsigned + (Str : String; + Ptr : access Integer; + Max : Integer) + return System.Unsigned_Types.Unsigned; + -- 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 that if a minus sign is present, and + -- the integer value is non-zero, then constraint error will be 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_Unsigned + (Str : String) + return System.Unsigned_Types.Unsigned; + -- Used in computing X'Value (Str) where X is a modular integer type whose + -- modulus does not exceed the range of System.Unsigned_Types.Unsigned. 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_Uns; |