1------------------------------------------------------------------------------ 2-- -- 3-- GNAT COMPILER COMPONENTS -- 4-- -- 5-- G N A T . A R R A Y _ S P L T -- 6-- -- 7-- S p e c -- 8-- -- 9-- Copyright (C) 2002-2003 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 2, 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. See the GNU General Public License -- 17-- for more details. You should have received a copy of the GNU General -- 18-- Public License distributed with GNAT; see file COPYING. If not, write -- 19-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, -- 20-- MA 02111-1307, USA. -- 21-- -- 22-- As a special exception, if other files instantiate generics from this -- 23-- unit, or you link this unit with other files to produce an executable, -- 24-- this unit does not by itself cause the resulting executable to be -- 25-- covered by the GNU General Public License. This exception does not -- 26-- however invalidate any other reasons why the executable file might be -- 27-- covered by the GNU Public License. -- 28-- -- 29-- GNAT was originally developed by the GNAT team at New York University. -- 30-- Extensive contributions were provided by Ada Core Technologies Inc. -- 31-- -- 32------------------------------------------------------------------------------ 33 34-- Useful array-manipulation routines: given a set of separators, split 35-- an array wherever the separators appear, and provide direct access 36-- to the resulting slices. 37 38with Ada.Finalization; 39 40generic 41 type Element is (<>); 42 -- Element of the array, this must be a discrete type 43 44 type Element_Sequence is array (Positive range <>) of Element; 45 -- The array which is a sequence of element. 46 47 type Element_Set is private; 48 -- This type represent a set of elements. This set does not defined a 49 -- specific order of the elements. The conversion of a sequence to a 50 -- set and membership tests in the set is performed using the routines 51 -- To_Set and Is_In defined below. 52 53 with function To_Set (Sequence : Element_Sequence) return Element_Set; 54 -- Returns an Element_Set given an Element_Sequence. Duplicate elements 55 -- can be ignored during this conversion. 56 57 with function Is_In (Item : Element; Set : Element_Set) return Boolean; 58 -- Returns True if Item is found in Set, False otherwise 59 60package GNAT.Array_Split is 61 62 Index_Error : exception; 63 -- Raised by all operations below if Index > Field_Count (S) 64 65 type Separator_Mode is 66 (Single, 67 -- In this mode the array is cut at each element in the separator 68 -- set. If two separators are contiguous the result at that position 69 -- is an empty slice. 70 71 Multiple 72 -- In this mode contiguous separators are handled as a single 73 -- separator and no empty slice is created. 74 ); 75 76 type Slice_Set is private; 77 -- This type uses by-reference semantics. This is a set of slices as 78 -- returned by Create or Set routines below. The abstraction represents 79 -- a set of items. Each item is a part of the original string named a 80 -- Slice. It is possible to access individual slices by using the Slice 81 -- routine below. The first slice in the Set is at the position/index 82 -- 1. The total number of slices in the set is returned by Slice_Count. 83 84 procedure Create 85 (S : out Slice_Set; 86 From : Element_Sequence; 87 Separators : Element_Sequence; 88 Mode : Separator_Mode := Single); 89 -- Create a cut array object. From is the source array, and Separators 90 -- is a sequence of Element along which to split the array. The source 91 -- array is sliced at separator boundaries. The separators are not 92 -- included as part of the resulting slices. 93 94 procedure Create 95 (S : out Slice_Set; 96 From : Element_Sequence; 97 Separators : Element_Set; 98 Mode : Separator_Mode := Single); 99 -- Same as above but using a Element_Set 100 101 procedure Set 102 (S : in out Slice_Set; 103 Separators : Element_Sequence; 104 Mode : Separator_Mode := Single); 105 -- Change the set of separators. The source array will be split according 106 -- to this new set of separators. 107 108 procedure Set 109 (S : in out Slice_Set; 110 Separators : Element_Set; 111 Mode : Separator_Mode := Single); 112 -- Same as above but using a Element_Set 113 114 type Slice_Number is new Natural; 115 -- Type used to count number of slices 116 117 function Slice_Count (S : Slice_Set) return Slice_Number; 118 pragma Inline (Slice_Count); 119 -- Returns the number of slices (fields) in S 120 121 function Slice 122 (S : Slice_Set; 123 Index : Slice_Number) 124 return Element_Sequence; 125 pragma Inline (Slice); 126 -- Returns the slice at position Index. First slice is 1. If Index is 0 127 -- the whole array is returned including the separators (this is the 128 -- original source array). 129 130 type Position is (Before, After); 131 -- Used to designate position of separator 132 133 type Slice_Separators is array (Position) of Element; 134 -- Separators found before and after the slice 135 136 Array_End : constant Element; 137 -- This is the separator returned for the start or the end of the array 138 139 function Separators 140 (S : Slice_Set; 141 Index : Slice_Number) 142 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 154private 155 156 Array_End : constant Element := Element'First; 157 158 type Element_Access is access Element_Sequence; 159 160 type Counter is access Natural; 161 162 type Indexes_Access is access Separators_Indexes; 163 164 type Slice_Info is record 165 Start : Positive; 166 Stop : Natural; 167 end record; 168 -- Starting/Ending position of a slice. This does not include separators. 169 170 type Slices_Indexes is array (Slice_Number range <>) of Slice_Info; 171 type Slices_Access is access Slices_Indexes; 172 -- All indexes for fast access to slices. In the Slice_Set we keep only 173 -- the original array and the indexes where each slice start and stop. 174 175 type Slice_Set is new Ada.Finalization.Controlled with record 176 Ref_Counter : Counter; -- Reference counter, by-address sem 177 Source : Element_Access; 178 N_Slice : Slice_Number := 0; -- Number of slices found 179 Indexes : Indexes_Access; 180 Slices : Slices_Access; 181 end record; 182 183 procedure Initialize (S : in out Slice_Set); 184 procedure Adjust (S : in out Slice_Set); 185 procedure Finalize (S : in out Slice_Set); 186 187end GNAT.Array_Split; 188