File : g-arrspl.ads
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT COMPILER COMPONENTS --
4 -- --
5 -- G N A T . A R R A Y _ S P L I T --
6 -- --
7 -- S p e c --
8 -- --
9 -- Copyright (C) 2002-2015, 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 -- --
19 -- --
20 -- --
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 -- Useful array-manipulation routines: given a set of separators, split
33 -- an array wherever the separators appear, and provide direct access
34 -- to the resulting slices.
35
36 with Ada.Finalization;
37
38 generic
39 type Element is (<>);
40 -- Element of the array, this must be a discrete type
41
42 type Element_Sequence is array (Positive range <>) of Element;
43 -- The array which is a sequence of element
44
45 type Element_Set is private;
46 -- This type represent a set of elements. This set does not define a
47 -- specific order of the elements. The conversion of a sequence to a
48 -- set and membership tests in the set is performed using the routines
49 -- To_Set and Is_In defined below.
50
51 with function To_Set (Sequence : Element_Sequence) return Element_Set;
52 -- Returns an Element_Set given an Element_Sequence. Duplicate elements
53 -- can be ignored during this conversion.
54
55 with function Is_In (Item : Element; Set : Element_Set) return Boolean;
56 -- Returns True if Item is found in Set, False otherwise
57
58 package GNAT.Array_Split is
59
60 Index_Error : exception;
61 -- Raised by all operations below if Index > Field_Count (S)
62
63 type Separator_Mode is
64 (Single,
65 -- In this mode the array is cut at each element in the separator
66 -- set. If two separators are contiguous the result at that position
67 -- is an empty slice.
68
69 Multiple
70 -- In this mode contiguous separators are handled as a single
71 -- separator and no empty slice is created.
72 );
73
74 type Slice_Set is private;
75 -- This type uses by-reference semantics. This is a set of slices as
76 -- returned by Create or Set routines below. The abstraction represents
77 -- a set of items. Each item is a part of the original array named a
78 -- Slice. It is possible to access individual slices by using the Slice
79 -- routine below. The first slice in the Set is at the position/index
80 -- 1. The total number of slices in the set is returned by Slice_Count.
81
82 procedure Create
83 (S : out Slice_Set;
84 From : Element_Sequence;
85 Separators : Element_Sequence;
86 Mode : Separator_Mode := Single);
87 -- Create a cut array object. From is the source array, and Separators
88 -- is a sequence of Element along which to split the array. The source
89 -- array is sliced at separator boundaries. The separators are not
90 -- included as part of the resulting slices.
91 --
92 -- Note that if From is terminated by a separator an extra empty element
93 -- is added to the slice set. If From only contains a separator the slice
94 -- set contains two empty elements.
95
96 procedure Create
97 (S : out Slice_Set;
98 From : Element_Sequence;
99 Separators : Element_Set;
100 Mode : Separator_Mode := Single);
101 -- Same as above but using a Element_Set
102
103 procedure Set
104 (S : in out Slice_Set;
105 Separators : Element_Sequence;
106 Mode : Separator_Mode := Single);
107 -- Change the set of separators. The source array will be split according
108 -- to this new set of separators.
109
110 procedure Set
111 (S : in out Slice_Set;
112 Separators : Element_Set;
113 Mode : Separator_Mode := Single);
114 -- Same as above but using a Element_Set
115
116 type Slice_Number is new Natural;
117 -- Type used to count number of slices
118
119 function Slice_Count (S : Slice_Set) return Slice_Number;
120 pragma Inline (Slice_Count);
121 -- Returns the number of slices (fields) in S
122
123 function Slice
124 (S : Slice_Set;
125 Index : Slice_Number) return Element_Sequence;
126 pragma Inline (Slice);
127 -- Returns the slice at position Index. First slice is 1. If Index is 0
128 -- the whole array is returned including the separators (this is the
129 -- original source array).
130
131 type Position is (Before, After);
132 -- Used to designate position of separator
133
134 type Slice_Separators is array (Position) of Element;
135 -- Separators found before and after the slice
136
137 Array_End : constant Element;
138 -- This is the separator returned for the start or the end of the array
139
140 function Separators
141 (S : Slice_Set;
142 Index : Slice_Number) return Slice_Separators;
143 -- Returns the separators used to slice (front and back) the slice at
144 -- position Index. For slices at start and end of the original array, the
145 -- Array_End value is returned for the corresponding outer bound. In
146 -- Multiple mode only the element closest to the slice is returned.
147 -- if Index = 0, returns (Array_End, Array_End).
148
149 type Separators_Indexes is array (Positive range <>) of Positive;
150
151 function Separators (S : Slice_Set) return Separators_Indexes;
152 -- Returns indexes of all separators used to slice original source array S
153
154 private
155
156 Array_End : constant Element := Element'First;
157
158 type Element_Access is access Element_Sequence;
159
160 type Indexes_Access is access Separators_Indexes;
161
162 type Slice_Info is record
163 Start : Positive;
164 Stop : Natural;
165 end record;
166 -- Starting/Ending position of a slice. This does not include separators
167
168 type Slices_Indexes is array (Slice_Number range <>) of Slice_Info;
169 type Slices_Access is access Slices_Indexes;
170 -- All indexes for fast access to slices. In the Slice_Set we keep only
171 -- the original array and the indexes where each slice start and stop.
172
173 type Data is record
174 Ref_Counter : Natural; -- Reference counter, by-address sem
175 Source : Element_Access;
176 N_Slice : Slice_Number := 0; -- Number of slices found
177 Indexes : Indexes_Access;
178 Slices : Slices_Access;
179 end record;
180 type Data_Access is access all Data;
181
182 type Slice_Set is new Ada.Finalization.Controlled with record
183 D : Data_Access;
184 end record;
185
186 procedure Initialize (S : in out Slice_Set);
187 procedure Adjust (S : in out Slice_Set);
188 procedure Finalize (S : in out Slice_Set);
189
190 end GNAT.Array_Split;