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-- --
-- --
-- G N A T . A R R A Y _ S P L I T --
-- --
-- S p e c --
-- --
-- Copyright (C) 2002-2021, 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 --
-- --
-- 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 --
-- <>. --
-- --
-- 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;
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 define 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
pragma Preelaborate;
Index_Error : exception;
-- Raised by all operations below if Index > Field_Count (S)
type Separator_Mode is
-- 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.
-- In this mode contiguous separators are handled as a single
-- separator and no empty slice is created.
type Slice_Set is private
with Iterable => (First => First_Cursor,
Next => Advance,
Has_Element => Has_Element,
Element => Slice);
-- 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 array 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);
function Create
(From : Element_Sequence;
Separators : Element_Sequence;
Mode : Separator_Mode := Single) return Slice_Set;
-- 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);
function Create
(From : Element_Sequence;
Separators : Element_Set;
Mode : Separator_Mode := Single) return Slice_Set;
-- 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 with Inline;
-- Returns the number of slices (fields) in S
function First_Cursor (Unused : Slice_Set) return Slice_Number is (1);
function Advance
(Unused : Slice_Set; Position : Slice_Number) return Slice_Number
is (Position + 1);
function Has_Element
(Cont : Slice_Set; Position : Slice_Number) return Boolean
is (Position <= Slice_Count (Cont));
-- Functions used to iterate over a Slice_Set
function Slice
(S : Slice_Set;
Index : Slice_Number) return Element_Sequence with Inline;
-- 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
Array_End : constant Element := Element'First;
type Element_Access is access Element_Sequence;
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 Data is record
Ref_Counter : Natural; -- 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;
type Data_Access is access all Data;
type Slice_Set is new Ada.Finalization.Controlled with record
D : Data_Access;
end record;
overriding procedure Initialize (S : in out Slice_Set);
overriding procedure Adjust (S : in out Slice_Set);
overriding procedure Finalize (S : in out Slice_Set);
end GNAT.Array_Split;