| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT COMPILER COMPONENTS -- |
| -- -- |
| -- S Y S T E M . V A L _ U T I L -- |
| -- -- |
| -- 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 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 Integer); |
| -- 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 Integer; |
| Max : Integer; |
| 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. Constraint_Error is |
| -- also raised in this case. |
| |
| function Scan_Exponent |
| (Str : String; |
| Ptr : access Integer; |
| Max : Integer; |
| 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. |
| |
| procedure Scan_Underscore |
| (Str : String; |
| P : in out Natural; |
| Ptr : access Integer; |
| Max : Integer; |
| Ext : Boolean); |
| -- Called if an underscore is encountered while scanning digits. Str (P) |
| -- contains the underscore. Ptr it the pointer to be returned to the |
| -- ultimate caller of the scan routine, Max is the maximum subscript in |
| -- Str, and Ext indicates if extended digits are allowed. In the case |
| -- where the underscore is invalid, Constraint_Error is raised with Ptr |
| -- set appropriately, otherwise control returns with P incremented past |
| -- the underscore. |
| |
| end System.Val_Util; |
