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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- G N A T . F O R M A T T E D _ S T R I N G --
-- --
-- S p e c --
-- --
-- Copyright (C) 2014-2021, 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 3, 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. --
-- --
-- As a special exception under Section 7 of GPL version 3, you are granted --
-- additional permissions described in the GCC Runtime Library Exception, --
-- version 3.1, as published by the Free Software Foundation. --
-- --
-- You should have received a copy of the GNU General Public License and --
-- a copy of the GCC Runtime Library Exception along with this program; --
-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
-- <http://www.gnu.org/licenses/>. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
-- This package add support for formatted string as supported by C printf()
-- A simple usage is:
--
-- Put_Line (-(+"%s" & "a string"));
--
-- or with a constant for the format:
--
-- declare
-- Format : constant Formatted_String := +"%s";
-- begin
-- Put_Line (-(Format & "a string"));
-- end;
--
-- Finally a more complex example:
--
-- declare
-- F : Formatted_String := +"['%c' ; %10d]";
-- C : Character := 'v';
-- I : Integer := 98;
-- begin
-- F := F & C & I;
-- Put_Line (-F);
-- end;
-- Which will display:
-- ['v' ; 98]
-- Each format specifier is: %[flags][width][.precision][length]specifier
-- Specifiers:
-- d or i Signed decimal integer
-- u Unsigned decimal integer
-- o Unsigned octal
-- x Unsigned hexadecimal integer
-- X Unsigned hexadecimal integer (uppercase)
-- f Decimal floating point, lowercase
-- F Decimal floating point, uppercase
-- e Scientific notation (mantissa/exponent), lowercase
-- E Scientific notation (mantissa/exponent), uppercase
-- g Use the shortest representation: %e or %f
-- G Use the shortest representation: %E or %F
-- c Character
-- s String of characters
-- p Pointer address
-- % A % followed by another % character will write a single %
-- Flags:
-- - Left-justify within the given field width;
-- Right justification is the default.
-- + Forces to preceed the result with a plus or minus sign (+ or -)
-- even for positive numbers. By default, only negative numbers
-- are preceded with a - sign.
-- (space) If no sign is going to be written, a blank space is inserted
-- before the value.
-- # Used with o, x or X specifiers the value is preceeded with
-- 0, 0x or 0X respectively for values different than zero.
-- Used with a, A, e, E, f, F, g or G it forces the written
-- output to contain a decimal point even if no more digits
-- follow. By default, if no digits follow, no decimal point is
-- written.
-- ~ As above, but using Ada style based <base>#<number>#
-- 0 Left-pads the number with zeroes (0) instead of spaces when
-- padding is specified.
-- Width:
-- number Minimum number of characters to be printed. If the value to
-- be printed is shorter than this number, the result is padded
-- with blank spaces. The value is not truncated even if the
-- result is larger.
-- * The width is not specified in the format string, but as an
-- additional integer value argument preceding the argument that
-- has to be formatted.
-- Precision:
-- number For integer specifiers (d, i, o, u, x, X): precision specifies
-- the minimum number of digits to be written. If the value to be
-- written is shorter than this number, the result is padded with
-- leading zeros. The value is not truncated even if the result
-- is longer. A precision of 0 means that no character is written
-- for the value 0.
-- For e, E, f and F specifiers: this is the number of digits to
-- be printed after the decimal point (by default, this is 6).
-- For g and G specifiers: This is the maximum number of
-- significant digits to be printed.
-- For s: this is the maximum number of characters to be printed.
-- By default all characters are printed until the ending null
-- character is encountered.
-- If the period is specified without an explicit value for
-- precision, 0 is assumed.
-- .* The precision is not specified in the format string, but as an
-- additional integer value argument preceding the argument that
-- has to be formatted.
with Ada.Text_IO;
with System;
private with Ada.Finalization;
private with Ada.Strings.Unbounded;
package GNAT.Formatted_String is
use Ada;
type Formatted_String (<>) is private;
-- A format string as defined for printf routine. This string is the
-- actual format for all the parameters added with the "&" routines below.
-- Note that a Formatted_String object can't be reused as it serves as
-- recipient for the final result. That is, each use of "&" will build
-- incrementally the final result string which can be retrieved with
-- the "-" routine below.
Format_Error : exception;
-- Raised for every mismatch between the parameter and the expected format
-- and for malformed format.
function "+" (Format : String) return Formatted_String;
-- Create the format string
function "-" (Format : Formatted_String) return String;
-- Get the result of the formatted string corresponding to the current
-- rendering (up to the last parameter formated).
function "&"
(Format : Formatted_String;
Var : Character) return Formatted_String;
-- A character, expect a %c
function "&"
(Format : Formatted_String;
Var : String) return Formatted_String;
-- A string, expect a %s
function "&"
(Format : Formatted_String;
Var : Boolean) return Formatted_String;
-- A boolean image, expect a %s
function "&"
(Format : Formatted_String;
Var : Integer) return Formatted_String;
-- An integer, expect a %d, %o, %x, %X
function "&"
(Format : Formatted_String;
Var : Long_Integer) return Formatted_String;
-- As above
function "&"
(Format : Formatted_String;
Var : System.Address) return Formatted_String;
-- An address, expect a %p
function "&"
(Format : Formatted_String;
Var : Float) return Formatted_String;
-- A float, expect %f, %e, %F, %E, %g, %G
function "&"
(Format : Formatted_String;
Var : Long_Float) return Formatted_String;
-- As above
function "&"
(Format : Formatted_String;
Var : Duration) return Formatted_String;
-- As above
-- Some generics
generic
type Int is range <>;
with procedure Put
(To : out String;
Item : Int;
Base : Text_IO.Number_Base);
function Int_Format
(Format : Formatted_String;
Var : Int) return Formatted_String;
-- As for Integer above
generic
type Int is mod <>;
with procedure Put
(To : out String;
Item : Int;
Base : Text_IO.Number_Base);
function Mod_Format
(Format : Formatted_String;
Var : Int) return Formatted_String;
-- As for Integer above
generic
type Flt is digits <>;
with procedure Put
(To : out String;
Item : Flt;
Aft : Text_IO.Field;
Exp : Text_IO.Field);
function Flt_Format
(Format : Formatted_String;
Var : Flt) return Formatted_String;
-- As for Float above
generic
type Flt is delta <>;
with procedure Put
(To : out String;
Item : Flt;
Aft : Text_IO.Field;
Exp : Text_IO.Field);
function Fixed_Format
(Format : Formatted_String;
Var : Flt) return Formatted_String;
-- As for Float above
generic
type Flt is delta <> digits <>;
with procedure Put
(To : out String;
Item : Flt;
Aft : Text_IO.Field;
Exp : Text_IO.Field);
function Decimal_Format
(Format : Formatted_String;
Var : Flt) return Formatted_String;
-- As for Float above
generic
type Enum is (<>);
function Enum_Format
(Format : Formatted_String;
Var : Enum) return Formatted_String;
-- As for String above, output the string representation of the enumeration
private
use Ada.Strings.Unbounded;
type I_Vars is array (Positive range 1 .. 2) of Integer;
-- Used to keep 2 numbers for the possible * for the width and precision
type Data (Size : Natural) is record
Ref_Count : Natural := 1;
Index : Positive := 1; -- format index for next value
Result : Unbounded_String; -- current value
Current : Natural; -- the current format number
Stored_Value : Natural := 0; -- number of stored values in Stack
Stack : I_Vars;
Format : String (1 .. Size); -- the format string
end record;
type Data_Access is access Data;
-- The formatted string record is controlled and do not need an initialize
-- as it requires an explit initial value. This is given with "+" and
-- properly initialize the record at this point.
type Formatted_String is new Finalization.Controlled with record
D : Data_Access;
end record;
overriding procedure Adjust (F : in out Formatted_String);
overriding procedure Finalize (F : in out Formatted_String);
end GNAT.Formatted_String;