Ada Programming/Libraries/GNAT.Array Split

-- --                                                                         -- --                         GNAT COMPILER COMPONENTS                         -- --                                                                         -- --                     G N A T. A R R A Y _ S P L I T                     -- --                                                                         -- --                                 S p e c                                  -- --                                                                         -- --          Copyright (C) 2002-2006, 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,  51  Franklin  Street,  Fifth  Floor, -- -- Boston, MA 02110-1301, USA. -- --                                                                         -- -- -- -- -- -- -- -- -- GNAT was originally developed  by the GNAT team at  New York University. -- -- Extensive contributions were provided by Ada Core Technologies Inc.     -- --                                                                         -- --

-- Useful array-manipulation routines: given a set of separators, split -- an array wherever the separators appear, and provide direct access -- to the resulting slices.

with Ada.Finalization;

generic type Element is (<>); -- Element of the array, this must be a discrete type

type Element_Sequence is array (Positive range <>) of Element; -- The array which is a sequence of element

type Element_Set is private; -- This type represent a set of elements. This set does not defined a  --  specific order of the elements. The conversion of a sequence to a  --  set and membership tests in the set is performed using the routines -- To_Set and Is_In defined below.

with function To_Set (Sequence : Element_Sequence) return Element_Set; -- Returns an Element_Set given an Element_Sequence. Duplicate elements -- can be ignored during this conversion.

with function Is_In (Item : Element; Set : Element_Set) return Boolean; -- Returns True if Item is found in Set, False otherwise

package GNAT.Array_Split is

Index_Error : exception; -- Raised by all operations below if Index > Field_Count (S)

type Separator_Mode is    (Single,      --  In this mode the array is cut at each element in the separator      --  set. If two separators are contiguous the result at that position      --  is an empty slice.

Multiple -- In this mode contiguous separators are handled as a single -- separator and no empty slice is created. );

type Slice_Set is private; -- This type uses by-reference semantics. This is a set of slices as  --  returned by Create or Set routines below. The abstraction represents -- a set of items. Each item is a part of the original string named a  --  Slice. It is possible to access individual slices by using the Slice -- routine below. The first slice in the Set is at the position/index -- 1. The total number of slices in the set is returned by Slice_Count.

procedure Create (S         : out Slice_Set;      From       : Element_Sequence;      Separators : Element_Sequence;      Mode       : Separator_Mode := Single); -- Create a cut array object. From is the source array, and Separators -- is a sequence of Element along which to split the array. The source -- array is sliced at separator boundaries. The separators are not -- included as part of the resulting slices. --  --  Note that if From is terminated by a separator an extra empty element -- is added to the slice set. If From only contains a separator the slice -- set contains two empty elements.

procedure Create (S         : out Slice_Set;      From       : Element_Sequence;      Separators : Element_Set;      Mode       : Separator_Mode := Single); -- Same as above but using a Element_Set

procedure Set (S         : in out Slice_Set;      Separators : Element_Sequence;      Mode       : Separator_Mode := Single); -- Change the set of separators. The source array will be split according -- to this new set of separators.

procedure Set (S         : in out Slice_Set;      Separators : Element_Set;      Mode       : Separator_Mode := Single); -- Same as above but using a Element_Set

type Slice_Number is new Natural; -- Type used to count number of slices

function Slice_Count (S : Slice_Set) return Slice_Number; pragma Inline (Slice_Count); -- Returns the number of slices (fields) in S

function Slice (S    : Slice_Set;      Index : Slice_Number) return Element_Sequence; pragma Inline (Slice); -- Returns the slice at position Index. First slice is 1. If Index is 0 -- the whole array is returned including the separators (this is the   --  original source array).

type Position is (Before, After); -- Used to designate position of separator

type Slice_Separators is array (Position) of Element; -- Separators found before and after the slice

Array_End : constant Element; -- This is the separator returned for the start or the end of the array

function Separators (S    : Slice_Set;      Index : Slice_Number) return Slice_Separators; -- Returns the separators used to slice (front and back) the slice at   --  position Index. For slices at start and end of the original array, the -- Array_End value is returned for the corresponding outer bound. In  --  Multiple mode only the element closest to the slice is returned. -- if Index = 0, returns (Array_End, Array_End).

type Separators_Indexes is array (Positive range <>) of Positive;

function Separators (S : Slice_Set) return Separators_Indexes; -- Returns indexes of all separators used to slice original source array S

private

Array_End : constant Element := Element'First;

type Element_Access is access Element_Sequence;

type Counter is access Natural;

type Indexes_Access is access Separators_Indexes;

type Slice_Info is record Start : Positive; Stop : Natural; end record; -- Starting/Ending position of a slice. This does not include separators

type Slices_Indexes is array (Slice_Number range <>) of Slice_Info; type Slices_Access is access Slices_Indexes; -- All indexes for fast access to slices. In the Slice_Set we keep only -- the original array and the indexes where each slice start and stop.

type Slice_Set is new Ada.Finalization.Controlled with record Ref_Counter : Counter;           -- Reference counter, by-address sem Source     : Element_Access; N_Slice    : Slice_Number := 0;  -- Number of slices found Indexes    : Indexes_Access; Slices     : Slices_Access; end record;

procedure Initialize (S : in out Slice_Set); procedure Adjust    (S : in out Slice_Set); procedure Finalize  (S : in out Slice_Set);

end GNAT.Array_Split; |GNAT.Array Split