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335 | -- --
-- package Strings_Edit Copyright (c) Dmitry A. Kazakov --
-- Interface Luebeck --
-- Spring, 2000 --
-- --
-- Last revision : 22:14 08 May 2009 --
-- --
-- This library is free software; you can redistribute it and/or --
-- modify it under the terms of the GNU General Public License as --
-- published by the Free Software Foundation; either version 2 of --
-- the License, or (at your option) any later version. This 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 --
-- General Public License for more details. You should have --
-- received a copy of the GNU General Public License along with --
-- this library; if not, write to the Free Software Foundation, --
-- Inc., 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. --
--____________________________________________________________________--
--
-- The following I/O items are supported by the package:
--
-- (o) Integer numbers (generic, package Integer_Edit)
-- (o) Floating-point numbers (generic, package Float_Edit)
-- (o) Roman numbers (the child package Roman_Edit)
-- (o) Strings
--
-- The major differences to the standard Image/Value attributes and
-- Text_IO procedures.
--
-- 1. For numeric types, the base is neither written nor read. For
-- instance, output of 23 as hexadecimal gives 17, not 16#17#.
--
-- 2. Get procedures do not skip blank characters around input tokens,
-- except the cases when the blank charactes is required by the
-- syntax.
--
-- 3. Get procedures use the current string position pointer, so that
-- they can be consequently called advancing the pointer as the tokes
-- are recognized.
--
-- 4. Numeric get procedures allow to specify the expected value range.
-- When the actual value is out of the range then depending on
-- procedure parameters, either Constrain_Error is propagated or the
-- value is forced to the nearest range boundary.
--
-- 5. Put procedures also use the current string position pointer, which
-- allows to call them consequently.
--
-- 6. The format used for floating-number output is based on the number
-- precision, instead of rather typographic approach of Text_IO. The
-- precision can be specified either as the number of valid digits of
-- the current base (i.e. relative) or as the position of the last
-- valid digit (i.e. absolute). For instance, 12.345678 with relative
-- precision 3 gives 12.3. With absolute precision -3, it gives
-- 12.346.
--
-- G E T P R O C E D U R E S
--
-- Get procedures are used to scan strings. The first two parameters are
-- always Source and Pointer. Source is the string to be scaned. Pointer
-- indicates the current position. After successful completion it is
-- advanced to the first string position following the recognized item.
-- The value of Pointer shall be in the range Source'First ..
-- Source'Last+1. The Layout_Error exception is propagated when this
-- check fails. The third parameter usually accepts the value. The
-- following example shows how to use get procedures:
--
-- package Edit_Float is new Strings_Edit.Float_Edit (Float);
-- use Edit_Float;
--
-- Line : String (1..512); -- A line
-- Pointer : Integer;
-- Value : Float;
-- TabAndSpace : Ada.Strings.Maps.Character_Set :=
-- To_Set (" " & Ada.Characters.Latin_1.HT);
-- begin
-- ...
-- Pointer := Line'First;
-- Get (Line, Pointer, TabAndSpace); -- Skip tabs and spaces
-- Get (Line, Pointer, Value); -- Get number
-- Get (Line, Pointer, TabAndSpace); -- Skip tabs and spaces
-- ...
--
-- The numeric Get procedures have additional parameters controlling the
-- range of the input value. The parameters First and Last define the
-- range of the expected value. The exception Constraint_Error is
-- propagated when the value is not in the range. The exception can be
-- suppressed using the parameters ToFirst and ToLast, which cause the
-- input value to be substituted by the corresponding margin when the
-- parameter is True.
--
-- V A L U E F U N C T I O N S
--
-- Each get procedure returning some value has a corresponding function
-- Value. The function Value has the same parameter profile with the
-- exception that the parameter Pointer is absent and the value is
-- returned via result. Unlike Get the function Value tolerates spaces
-- and tabs around the converted value. The whole string should be
-- matched, otherwise, the exception Data_Error is propagated.
--
-- P U T P R O C E D U R E S
--
-- Put procedures place something into the output string Destination.
-- The string is written starting from Destination (Pointer). The
-- parameter Field defines the output size. When it has the value zero
-- then the output size is defined by the output item. Otherwise the
-- output is justified within the field and the parameter Justify
-- specifies output alignment and the parameter Fill gives the pad
-- character. When Field is greater than Destination'Last - Pointer + 1,
-- the later is used instead. After successful completion Pointer is
-- advanced to the first character following the output or to
-- Destination'Last + 1.
--
-- I M A G E F U N C T I O N S
--
-- Image functions convert a value into string. Unlike standard S'Image
-- they do not place an extra space character.
--
with Ada.Strings.Maps; use Ada.Strings.Maps;
with Ada.Strings;
with Ada.Characters.Latin_1;
package Strings_Edit is
pragma Elaborate_Body (Strings_Edit);
MaxSmall : constant := 250; -- Bigger than any possible
Figures : constant String := "0123456789ABCDEF";
Blanks : constant String := ' ' & Ada.Characters.Latin_1.HT;
SpaceAndTab : constant Character_Set := To_Set (Blanks);
subtype Alignment is Ada.Strings.Alignment;
Center : Alignment renames Ada.Strings.Center;
Left : Alignment renames Ada.Strings.Left;
Right : Alignment renames Ada.Strings.Right;
subtype NumberBase is Integer range 2..16;
--
-- S T R I N G S
--
-- Get -- Skip blank characters
--
-- Source - The string to be processed
-- Pointer - The current position in the string
-- Blank - The blank character
--
-- This procedure skips the character Blank starting from Source
-- (Pointer). Pointer is advanced to the first non-Blank character or
-- to Source'Last + 1.
--
-- Exceptions :
--
-- Layout_Error - Pointer is not in Source'First..Source'Last + 1
--
procedure Get
( Source : String;
Pointer : in out Integer;
Blank : Character := ' '
);
--
-- Get -- Skip blank characters
--
-- Source - The string to be processed
-- Pointer - The current position in the string
-- Blanks - The set characters to be considered as blank ones
--
-- This procedure skips all the characters of the set Blanks starting
-- from Source (Pointer). Pointer is advanced to the first non-blank
-- character or to Source'Last + 1.
--
-- Exceptions :
--
-- Layout_Error - Pointer is not in Source'First..Source'Last + 1
--
procedure Get
( Source : String;
Pointer : in out Integer;
Blanks : Character_Set
);
--
-- Put -- Put a character into a string
--
-- Destination - The string that accepts the output
-- Pointer - The current position in the string
-- Value - The character to be put
-- Field - The output field
-- Justify - Alignment within the field
-- Fill - The fill character
--
-- This procedure places the specified character (Value parameter)
-- into the output string Destination. The string is written starting
-- from the Destination (Pointer).
--
-- Exceptions:
--
-- Layout_Error - Pointer is not in Destination'Range or there is
-- no room for the output.
--
procedure Put
( Destination : in out String;
Pointer : in out Integer;
Value : Character;
Field : Natural := 0;
Justify : Alignment := Left;
Fill : Character := ' '
);
--
-- Put -- Put a string into another string
--
-- Destination - The string that accepts the output
-- Pointer - The current position in the string
-- Value - The string to be put
-- Field - The output field
-- Justify - Alignment within the field
-- Fill - The fill character
--
-- This procedure places the specified by the Value parameter string
-- into the output string Destination. The string is written starting
-- from the Destination (Pointer).
--
-- Exceptions:
--
-- Layout_Error - Pointer is not in Destination'Range or there is
-- no room for the output.
--
procedure Put
( Destination : in out String;
Pointer : in out Integer;
Value : String;
Field : Natural := 0;
Justify : Alignment := Left;
Fill : Character := ' '
);
--
-- R O M A N N U M B E R S
--
-- Roman_Edit -- Child package for roman numbers
--
-- I N T E G E R N U M B E R S
--
-- Integer_Edit -- Generic child package for integer numbers
--
-- F L O A T I N G - P O I N T N U M B E R S
--
-- Float_Edit -- Generic child package for floating-point numbers
--
-- P R E F I X T E S T
--
--
-- Is_Prefix -- Test if Prefix is a prefix of Text
--
-- Prefix - To check
-- Source - The string
-- [ Pointer ] - To start at
-- [ Map ] - Used to convert characters before comparison
--
-- Returns :
--
-- True if Prefix is a prefix of Source
--
function Is_Prefix (Prefix, Source : String) return Boolean;
function Is_Prefix
( Prefix, Source : String;
Pointer : Integer
) return Boolean;
function Is_Prefix
( Prefix, Source : String;
Map : Character_Mapping
) return Boolean;
function Is_Prefix
( Prefix, Source : String;
Pointer : Integer;
Map : Character_Mapping
) return Boolean;
--
-- T R I M F U N C T I O N S
--
-- Trim -- Delete blank characters form string ends
--
-- Source - The string to be processed
-- Blank - The blank character
--
-- This function removes the Blank character from both ends of the
-- string and returns the result.
--
-- Returns :
--
-- The result string
--
function Trim
( Source : String;
Blank : Character := ' '
) return String;
--
-- Trim -- Delete blank characters form string ends
--
-- Source - The string to be processed
-- Blanks - The set of blank characters
--
-- This function removes any characters of the Blanks set from both
-- ends of the string and returns the result.
--
-- Returns :
--
-- The result string
--
function Trim
( Source : String;
Blanks : Character_Set
) return String;
private
pragma Inline (Is_Prefix);
--
-- GetDigit -- Get one digit
--
-- Symbol - To be decoded
--
-- Returns :
--
-- [0..15] The decoded digit value
-- [16] The Symbol is not a digit
--
function GetDigit (Symbol : Character) return Natural;
pragma Inline (GetDigit);
end Strings_Edit;
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