------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- S Y S T E M . V A L _ U T I L -- -- -- -- S p e c -- -- -- -- $Revision: 2 $ -- -- -- -- Copyright (c) 1992,1993,1994 NYU, All Rights Reserved -- -- -- -- The GNAT library is free software; you can redistribute it and/or modify -- -- it under terms of the GNU Library General Public License as published by -- -- the Free Software Foundation; either version 2, or (at your option) any -- -- later version. The GNAT library is distributed in the hope that it will -- -- be useful, but WITHOUT ANY WARRANTY; without even the implied warranty -- -- of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU -- -- Library General Public License for more details. You should have -- -- received a copy of the GNU Library General Public License along with -- -- the GNAT library; see the file COPYING.LIB. If not, write to the Free -- -- Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. -- -- -- ------------------------------------------------------------------------------ -- This package provides some common utilities used by the s-valxxx files package System.Val_Util is pragma Pure (Val_Util); procedure Normalize_String (S : in out String; F, L : out Positive'Base); -- This procedure scans the string S setting F to be the index of the first -- non-blank character of S and L to be the index of the last non-blank -- character of S. Any lower case characters present in S will be folded -- to their upper case equivalent except for character literals. If S -- consists of entirely blanks then Constraint_Error is raised. -- -- Note: if S is the null string, F is set to S'First, L to S'Last procedure Scan_Sign (Str : String; Ptr : access Positive'Base; Max : Positive'Base; Minus : out Boolean; Start : out Positive); -- The Str, Ptr, Max parameters are as for the scan routines (Str is the -- string to be scanned starting at Ptr.all, and Max is the index of the -- last character in the string). Scan_Sign first scans out any initial -- blanks, raising Constraint_Error if the field is all blank. It then -- checks for and skips an initial plus or minus, requiring a non-blank -- character to follow (Constraint_Error is raised if plus or minus -- appears at the end of the string or with a following blank). Minus is -- set True if a minus sign was skipped, and False otherwise. On exit -- Ptr.all points to the character after the sign, or to the first -- non-blank character if no sign is present. Start is set to the point -- to the first non-blank character (sign or digit after it). -- -- 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 Scan_Exponent (Str : String; Ptr : access Positive'Base; Max : Positive'Base; Real : Boolean := False) return Integer; -- Called to scan a possible exponent. Str, Ptr, Max are as described above -- for Scan_Sign. If Ptr.all < Max and Str (Ptr.all) = 'E' or 'e', then an -- exponent is scanned out, with the exponent value returned in Exp, and -- Ptr.all updated to point past the exponent. If the exponent field is -- incorrectly formed or not present, then Ptr.all is unchanged, and the -- returned exponent value is zero. Real indicates whether a minus sign -- is permitted (True = permitted). Very large exponents are handled by -- returning a suitable large value. If the base is zero, then any value -- is allowed, and otherwise the large value will either cause underflow -- or overflow during the scaling process which is fine. procedure Scan_Trailing_Blanks (Str : String; P : Positive); -- Checks that the remainder of the field Str (P .. Str'Last) is all -- blanks. Raises Constraint_Error if a non-blank character is found. end System.Val_Util;