------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- S Y S T E M . V A L U E _ D -- -- -- -- S p e c -- -- -- -- Copyright (C) 2020-2024, 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 3, 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. -- -- -- -- As a special exception under Section 7 of GPL version 3, you are granted -- -- additional permissions described in the GCC Runtime Library Exception, -- -- version 3.1, as published by the Free Software Foundation. -- -- -- -- You should have received a copy of the GNU General Public License and -- -- a copy of the GCC Runtime Library Exception along with this program; -- -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- -- . -- -- -- -- GNAT was originally developed by the GNAT team at New York University. -- -- Extensive contributions were provided by Ada Core Technologies Inc. -- -- -- ------------------------------------------------------------------------------ -- This package contains the routines for supporting the Value attribute for -- decimal fixed point types, and also for conversion operations required in -- Text_IO.Decimal_IO for such types. generic type Int is range <>; type Uns is mod <>; with procedure Scaled_Divide (X, Y, Z : Int; Q, R : out Int; Round : Boolean); package System.Value_D is pragma Preelaborate; function Scan_Decimal (Str : String; Ptr : not null access Integer; Max : Integer; Scale : Integer) return Int; -- 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 -- Int'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 Int; -- Used in computing X'Value (Str) where X is a decimal fixed-point type. -- 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 of Int (not -- the range of the fixed-point type, which must be done by the caller). -- Otherwise the value returned is the value Int'Integer_Value -- (decimal-literal-value), using Scale to determine this value. end System.Value_D;