1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
|
-- --
-- package Strings_Edit Copyright (c) Dmitry A. Kazakov --
-- Interface Luebeck --
-- Spring, 2000 --
-- --
-- Last revision : 10:11 25 Jun 2005 --
-- --
-- This library is free software; you can redistribute it and/or --
-- modify it under the terms of the GNU General Public License as --
-- published by the Free Software Foundation; either version 2 of --
-- the License, or (at your option) any later version. This library --
-- is distributed in the hope that it will be useful, but WITHOUT --
-- 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 along with --
-- this library; if not, write to the Free Software Foundation, --
-- Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. --
-- --
-- --
-- --
-- --
-- --
-- --
-- --
--____________________________________________________________________--
--
-- The following I/O items are supported by the package:
--
-- (o) Integer numbers (generic, package Integer_Edit)
-- (o) Floating-point numbers (generic, package Float_Edit)
-- (o) Roman numbers (the child package Roman_Edit)
-- (o) Strings
--
-- The major differences to the standard Image/Value attributes and
-- Text_IO procedures.
--
-- 1. For numeric types, the base is neither written nor read. For
-- instance, output of 23 as hexadecimal gives 17, not 16#17#.
--
-- 2. Get procedures do not skip blank characters around input tokens,
-- except the cases when the blank charactes is required by the
-- syntax.
--
-- 3. Get procedures use the current string position pointer, so that
-- they can be consequently called advancing the pointer as the tokes
-- are recognized.
--
-- 4. Numeric get procedures allow to specify the expected value range.
-- When the actual value is out of the range then depending on
-- procedure parameters, either Constrain_Error is propagated or the
-- value is forced to the nearest range boundary.
--
-- 5. Put procedures also use the current string position pointer, which
-- allows to call them consequently.
--
-- 6. The format used for floating-number output is based on the number
-- precision, instead of rather typographic approach of Text_IO. The
-- precision can be specified either as the number of valid digits of
-- the current base (i.e. relative) or as the position of the last
-- valid digit (i.e. absolute). For instance, 12.345678 with relative
-- precision 3 gives 12.3. With absolute precision -3, it gives
-- 12.346.
--
-- G E T P R O C E D U R E S
--
-- Get procedures are used to scan strings. The first two parameters are
-- always Source and Pointer. Source is the string to be scaned. Pointer
-- indicates the current position. After successful completion it is
-- advanced to the first string position following the recognized item.
-- The value of Pointer shall be in the range Source'First ..
-- Source'Last+1. The Layout_Error exception is propagated when this
-- check fails. The third parameter usually accepts the value. The
-- following example shows how to use get procedures:
--
-- package Edit_Float is new Strings_Edit.Float_Edit (Float);
-- use Edit_Float;
--
-- Line : String (1..512); -- A line
-- Pointer : Integer;
-- Value : Float;
-- TabAndSpace : Ada.Strings.Maps.Character_Set :=
-- To_Set (" " & Ada.Characters.Latin_1.HT);
-- begin
-- ...
-- Pointer := Line'First;
-- Get (Line, Pointer, TabAndSpace); -- Skip tabs and spaces
-- Get (Line, Pointer, Value); -- Get number
-- Get (Line, Pointer, TabAndSpace); -- Skip tabs and spaces
-- ...
--
-- The numeric Get procedures have additional parameters controlling the
-- range of the input value. The parameters First and Last define the
-- range of the expected value. The exception Constraint_Error is
-- propagated when the value is not in the range. The exception can be
-- suppressed using the parameters ToFirst and ToLast, which cause the
-- input value to be substituted by the corresponding margin when the
-- parameter is True.
--
-- V A L U E F U N C T I O N S
--
-- Each get procedure returning some value has a corresponding function
-- Value. The function Value has the same parameter profile with the
-- exception that the parameter Pointer is absent and the value is
-- returned via result. Unlike Get the function Value tolerates spaces
-- and tabs around the converted value. The whole string should be
-- matched, otherwise, the exception Data_Error is propagated.
--
-- P U T P R O C E D U R E S
--
-- Put procedures place something into the output string Destination.
-- The string is written starting from Destination (Pointer). The
-- parameter Field defines the output size. When it has the value zero
-- then the output size is defined by the output item. Otherwise the
-- output is justified within the field and the parameter Justify
-- specifies output alignment and the parameter Fill gives the pad
-- character. When Field is greater than Destination'Last - Pointer + 1,
-- the later is used instead. After successful completion Pointer is
-- advanced to the first character following the output or to
-- Destination'Last + 1.
--
-- I M A G E F U N C T I O N S
--
-- Image functions convert a value into string. Unlike standard S'Image
-- they do not place an extra space character.
--
with Ada.Strings;
with Ada.Strings.Maps;
with Ada.Characters.Latin_1;
package Strings_Edit is
pragma Elaborate_Body (Strings_Edit);
MaxSmall : constant := 250; -- Bigger than any possible
Figures : constant String := "0123456789ABCDEF";
Blanks : constant String := ' ' & Ada.Characters.Latin_1.HT;
SpaceAndTab : constant Ada.Strings.Maps.Character_Set :=
Ada.Strings.Maps.To_Set (Blanks);
subtype Alignment is Ada.Strings.Alignment;
Center : Alignment renames Ada.Strings.Center;
Left : Alignment renames Ada.Strings.Left;
Right : Alignment renames Ada.Strings.Right;
subtype NumberBase is Integer range 2..16;
--
-- S T R I N G S
--
-- Get -- Skip blank characters
--
-- Source - The string to be processed
-- Pointer - The current position in the string
-- Blank - The blank character
--
-- This procedure skips the character Blank starting from Source
-- (Pointer). Pointer is advanced to the first non-Blank character or
-- to Source'Last + 1.
--
-- Exceptions :
--
-- Layout_Error - Pointer is not in Source'First..Source'Last + 1
--
procedure Get
( Source : in String;
Pointer : in out Integer;
Blank : in Character := ' '
);
--
-- Get -- Skip blank characters
--
-- Source - The string to be processed
-- Pointer - The current position in the string
-- Blanks - The set characters to be considered as blank ones
--
-- This procedure skips all the characters of the set Blanks starting
-- from Source (Pointer). Pointer is advanced to the first non-blank
-- character or to Source'Last + 1.
--
-- Exceptions :
--
-- Layout_Error - Pointer is not in Source'First..Source'Last + 1
--
procedure Get
( Source : in String;
Pointer : in out Integer;
Blanks : in Ada.Strings.Maps.Character_Set
);
--
-- Put -- Put a character into a string
--
-- Destination - The string that accepts the output
-- Pointer - The current position in the string
-- Value - The character to be put
-- Field - The output field
-- Justify - Alignment within the field
-- Fill - The fill character
--
-- This procedure places the specified character (Value parameter)
-- into the output string Destination. The string is written starting
-- from the Destination (Pointer).
--
-- Exceptions:
--
-- Layout_Error - Pointer is not in Destination'Range or there is
-- no room for the output.
--
procedure Put
( Destination : in out String;
Pointer : in out Integer;
Value : in Character;
Field : in Natural := 0;
Justify : in Alignment := Left;
Fill : in Character := ' '
);
--
-- Put -- Put a string into another string
--
-- Destination - The string that accepts the output
-- Pointer - The current position in the string
-- Value - The string to be put
-- Field - The output field
-- Justify - Alignment within the field
-- Fill - The fill character
--
-- This procedure places the specified by the Value parameter string
-- into the output string Destination. The string is written starting
-- from the Destination (Pointer).
--
-- Exceptions:
--
-- Layout_Error - Pointer is not in Destination'Range or there is
-- no room for the output.
--
procedure Put
( Destination : in out String;
Pointer : in out Integer;
Value : in String;
Field : in Natural := 0;
Justify : in Alignment := Left;
Fill : in Character := ' '
);
--
-- R O M A N N U M B E R S
--
-- Roman_Edit -- Child package for roman numbers
--
-- I N T E G E R N U M B E R S
--
-- Integer_Edit -- Generic child package for integer numbers
--
-- F L O A T I N G - P O I N T N U M B E R S
--
-- Float_Edit -- Generic child package for floating-point numbers
--
-- T R I M F U N C T I O N S
--
-- Trim -- Delete blank characters form string ends
--
-- Source - The string to be processed
-- Blank - The blank character
--
-- This function removes the Blank character from both ends of the
-- string and returns the result.
--
-- Returns :
--
-- The result string
--
function Trim
( Source : in String;
Blank : in Character := ' '
) return String;
--
-- Trim -- Delete blank characters form string ends
--
-- Source - The string to be processed
-- Blanks - The set of blank characters
--
-- This function removes any characters of the Blanks set from both
-- ends of the string and returns the result.
--
-- Returns :
--
-- The result string
--
function Trim
( Source : in String;
Blanks : in Ada.Strings.Maps.Character_Set
) return String;
private
--
-- GetDigit -- Get one digit
--
-- Symbol - To be decoded
--
-- Returns :
--
-- [0..15] The decoded digit value
-- [16] The Symbol is not a digit
--
function GetDigit (Symbol : Character) return Natural;
pragma Inline (GetDigit);
end Strings_Edit;
|
