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
|
------------------------------------------------------------------------------
-- --
-- GNAT RUN-TIME COMPONENTS --
-- --
-- G N A T . S P E L L I N G _ C H E C K E R _ G E N E R I C --
-- --
-- B o d y --
-- --
-- Copyright (C) 1998-2007, AdaCore --
-- --
-- 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. --
-- --
-- As a special exception, if other files instantiate generics from this --
-- unit, or you link this unit with other files to produce an executable, --
-- this unit does not by itself cause the resulting executable to be --
-- covered by the GNU General Public License. This exception does not --
-- however invalidate any other reasons why the executable file might be --
-- covered by the GNU Public License. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
pragma Warnings (Off);
pragma Compiler_Unit;
pragma Warnings (On);
package body GNAT.Spelling_Checker_Generic is
------------------------
-- Is_Bad_Spelling_Of --
------------------------
function Is_Bad_Spelling_Of
(Found : String_Type;
Expect : String_Type) return Boolean
is
FN : constant Natural := Found'Length;
FF : constant Natural := Found'First;
FL : constant Natural := Found'Last;
EN : constant Natural := Expect'Length;
EF : constant Natural := Expect'First;
EL : constant Natural := Expect'Last;
Letter_o : constant Char_Type := Char_Type'Val (Character'Pos ('o'));
Digit_0 : constant Char_Type := Char_Type'Val (Character'Pos ('0'));
Digit_9 : constant Char_Type := Char_Type'Val (Character'Pos ('9'));
begin
-- If both strings null, then we consider this a match, but if one
-- is null and the other is not, then we definitely do not match
if FN = 0 then
return (EN = 0);
elsif EN = 0 then
return False;
-- If first character does not match, then we consider that this is
-- definitely not a misspelling. An exception is when we expect a
-- letter O and found a zero.
elsif Found (FF) /= Expect (EF)
and then (Found (FF) /= Digit_0 or else Expect (EF) /= Letter_o)
then
return False;
-- Not a bad spelling if both strings are 1-2 characters long
elsif FN < 3 and then EN < 3 then
return False;
-- Lengths match. Execute loop to check for a single error, single
-- transposition or exact match (we only fall through this loop if
-- one of these three conditions is found).
elsif FN = EN then
for J in 1 .. FN - 2 loop
if Expect (EF + J) /= Found (FF + J) then
-- If both mismatched characters are digits, then we do
-- not consider it a misspelling (e.g. B345 is not a
-- misspelling of B346, it is something quite different)
if Expect (EF + J) in Digit_0 .. Digit_9
and then Found (FF + J) in Digit_0 .. Digit_9
then
return False;
elsif Expect (EF + J + 1) = Found (FF + J + 1)
and then Expect (EF + J + 2 .. EL) = Found (FF + J + 2 .. FL)
then
return True;
elsif Expect (EF + J) = Found (FF + J + 1)
and then Expect (EF + J + 1) = Found (FF + J)
and then Expect (EF + J + 2 .. EL) = Found (FF + J + 2 .. FL)
then
return True;
else
return False;
end if;
end if;
end loop;
-- At last character. Test digit case as above, otherwise we
-- have a match since at most this last character fails to match.
if Expect (EL) in Digit_0 .. Digit_9
and then Found (FL) in Digit_0 .. Digit_9
and then Expect (EL) /= Found (FL)
then
return False;
else
return True;
end if;
-- Length is 1 too short. Execute loop to check for single deletion
elsif FN = EN - 1 then
for J in 1 .. FN - 1 loop
if Found (FF + J) /= Expect (EF + J) then
return Found (FF + J .. FL) = Expect (EF + J + 1 .. EL);
end if;
end loop;
-- If we fall through then the last character was missing, which
-- we consider to be a match (e.g. found xyz, expected xyza).
return True;
-- Length is 1 too long. Execute loop to check for single insertion
elsif FN = EN + 1 then
for J in 1 .. EN - 1 loop
if Found (FF + J) /= Expect (EF + J) then
return Found (FF + J + 1 .. FL) = Expect (EF + J .. EL);
end if;
end loop;
-- If we fall through then the last character was an additional
-- character, which is a match (e.g. found xyza, expected xyz).
return True;
-- Length is completely wrong
else
return False;
end if;
end Is_Bad_Spelling_Of;
end GNAT.Spelling_Checker_Generic;
|
