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) 1992-2014, 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 to 47 -- their upper case equivalent except for character literals. If S consists 48 -- 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 appears 64 -- at the end of the string or with a following blank). Minus is set True 65 -- if a minus sign was skipped, and False otherwise. On exit Ptr.all points 66 -- to the character after the sign, or to the first non-blank character 67 -- if no sign is present. Start is set to the point to the first non-blank 68 -- 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 also 73 -- raised in this case. 74 -- 75 -- This routine must not be called with Str'Last = Positive'Last. There is 76 -- no check for this case, the caller must ensure this condition is met. 77 78 procedure Scan_Plus_Sign 79 (Str : String; 80 Ptr : not null access Integer; 81 Max : Integer; 82 Start : out Positive); 83 -- Same as Scan_Sign, but allows only plus, not minus. This is used for 84 -- modular types. 85 86 function Scan_Exponent 87 (Str : String; 88 Ptr : not null access Integer; 89 Max : Integer; 90 Real : Boolean := False) return Integer; 91 -- Called to scan a possible exponent. Str, Ptr, Max are as described above 92 -- for Scan_Sign. If Ptr.all < Max and Str (Ptr.all) = 'E' or 'e', then an 93 -- exponent is scanned out, with the exponent value returned in Exp, and 94 -- Ptr.all updated to point past the exponent. If the exponent field is 95 -- incorrectly formed or not present, then Ptr.all is unchanged, and the 96 -- returned exponent value is zero. Real indicates whether a minus sign 97 -- is permitted (True = permitted). Very large exponents are handled by 98 -- returning a suitable large value. If the base is zero, then any value 99 -- is allowed, and otherwise the large value will either cause underflow 100 -- or overflow during the scaling process which is fine. 101 -- 102 -- This routine must not be called with Str'Last = Positive'Last. There is 103 -- no check for this case, the caller must ensure this condition is met. 104 105 procedure Scan_Trailing_Blanks (Str : String; P : Positive); 106 -- Checks that the remainder of the field Str (P .. Str'Last) is all 107 -- blanks. Raises Constraint_Error if a non-blank character is found. 108 109 procedure Scan_Underscore 110 (Str : String; 111 P : in out Natural; 112 Ptr : not null access Integer; 113 Max : Integer; 114 Ext : Boolean); 115 -- Called if an underscore is encountered while scanning digits. Str (P) 116 -- contains the underscore. Ptr it the pointer to be returned to the 117 -- ultimate caller of the scan routine, Max is the maximum subscript in 118 -- Str, and Ext indicates if extended digits are allowed. In the case 119 -- where the underscore is invalid, Constraint_Error is raised with Ptr 120 -- set appropriately, otherwise control returns with P incremented past 121 -- the underscore. 122 -- 123 -- This routine must not be called with Str'Last = Positive'Last. There is 124 -- no check for this case, the caller must ensure this condition is met. 125 126end System.Val_Util; 127