1------------------------------------------------------------------------------ 2-- -- 3-- GNAT COMPILER COMPONENTS -- 4-- -- 5-- S Y S T E M . V A L _ U T I L -- 6-- -- 7-- S p e c -- 8-- -- 9-- Copyright (C) 1992-2012, Free Software Foundation, Inc. -- 10-- -- 11-- GNAT is free software; you can redistribute it and/or modify it under -- 12-- terms of the GNU General Public License as published by the Free Soft- -- 13-- ware Foundation; either version 3, or (at your option) any later ver- -- 14-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- 15-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- 16-- or FITNESS FOR A PARTICULAR PURPOSE. -- 17-- -- 18-- As a special exception under Section 7 of GPL version 3, you are granted -- 19-- additional permissions described in the GCC Runtime Library Exception, -- 20-- version 3.1, as published by the Free Software Foundation. -- 21-- -- 22-- You should have received a copy of the GNU General Public License and -- 23-- a copy of the GCC Runtime Library Exception along with this program; -- 24-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- 25-- <http://www.gnu.org/licenses/>. -- 26-- -- 27-- GNAT was originally developed by the GNAT team at New York University. -- 28-- Extensive contributions were provided by Ada Core Technologies Inc. -- 29-- -- 30------------------------------------------------------------------------------ 31 32-- This package provides some common utilities used by the s-valxxx files 33 34package System.Val_Util is 35 pragma Pure; 36 37 procedure Bad_Value (S : String); 38 pragma No_Return (Bad_Value); 39 -- Raises constraint error with message: bad input for 'Value: "xxx" 40 41 procedure Normalize_String 42 (S : in out String; 43 F, L : out Integer); 44 -- This procedure scans the string S setting F to be the index of the first 45 -- non-blank character of S and L to be the index of the last non-blank 46 -- character of S. Any lower case characters present in S will be folded 47 -- to their upper case equivalent except for character literals. If S 48 -- consists of entirely blanks then Constraint_Error is raised. 49 -- 50 -- Note: if S is the null string, F is set to S'First, L to S'Last 51 52 procedure Scan_Sign 53 (Str : String; 54 Ptr : not null access Integer; 55 Max : Integer; 56 Minus : out Boolean; 57 Start : out Positive); 58 -- The Str, Ptr, Max parameters are as for the scan routines (Str is the 59 -- string to be scanned starting at Ptr.all, and Max is the index of the 60 -- last character in the string). Scan_Sign first scans out any initial 61 -- blanks, raising Constraint_Error if the field is all blank. It then 62 -- checks for and skips an initial plus or minus, requiring a non-blank 63 -- character to follow (Constraint_Error is raised if plus or minus 64 -- appears at the end of the string or with a following blank). Minus is 65 -- set True if a minus sign was skipped, and False otherwise. On exit 66 -- Ptr.all points to the character after the sign, or to the first 67 -- non-blank character if no sign is present. Start is set to the point 68 -- to the first non-blank character (sign or digit after it). 69 -- 70 -- Note: if Str is null, i.e. if Max is less than Ptr, then this is a 71 -- special case of an all-blank string, and Ptr is unchanged, and hence 72 -- is greater than Max as required in this case. Constraint_Error is 73 -- also raised in this case. 74 75 procedure Scan_Plus_Sign 76 (Str : String; 77 Ptr : not null access Integer; 78 Max : Integer; 79 Start : out Positive); 80 -- Same as Scan_Sign, but allows only plus, not minus. 81 -- This is used for modular types. 82 83 function Scan_Exponent 84 (Str : String; 85 Ptr : not null access Integer; 86 Max : Integer; 87 Real : Boolean := False) return Integer; 88 -- Called to scan a possible exponent. Str, Ptr, Max are as described above 89 -- for Scan_Sign. If Ptr.all < Max and Str (Ptr.all) = 'E' or 'e', then an 90 -- exponent is scanned out, with the exponent value returned in Exp, and 91 -- Ptr.all updated to point past the exponent. If the exponent field is 92 -- incorrectly formed or not present, then Ptr.all is unchanged, and the 93 -- returned exponent value is zero. Real indicates whether a minus sign 94 -- is permitted (True = permitted). Very large exponents are handled by 95 -- returning a suitable large value. If the base is zero, then any value 96 -- is allowed, and otherwise the large value will either cause underflow 97 -- or overflow during the scaling process which is fine. 98 99 procedure Scan_Trailing_Blanks (Str : String; P : Positive); 100 -- Checks that the remainder of the field Str (P .. Str'Last) is all 101 -- blanks. Raises Constraint_Error if a non-blank character is found. 102 103 procedure Scan_Underscore 104 (Str : String; 105 P : in out Natural; 106 Ptr : not null access Integer; 107 Max : Integer; 108 Ext : Boolean); 109 -- Called if an underscore is encountered while scanning digits. Str (P) 110 -- contains the underscore. Ptr it the pointer to be returned to the 111 -- ultimate caller of the scan routine, Max is the maximum subscript in 112 -- Str, and Ext indicates if extended digits are allowed. In the case 113 -- where the underscore is invalid, Constraint_Error is raised with Ptr 114 -- set appropriately, otherwise control returns with P incremented past 115 -- the underscore. 116 117end System.Val_Util; 118