1 ------------------------------------------------------------------------------
3 -- GNAT RUN-TIME COMPONENTS --
5 -- G N A T . S P E L L I N G _ C H E C K E R --
9 -- Copyright (C) 1998-2006, AdaCore --
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, 51 Franklin Street, Fifth Floor, --
20 -- Boston, MA 02110-1301, USA. --
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. --
29 -- GNAT was originally developed by the GNAT team at New York University. --
30 -- Extensive contributions were provided by Ada Core Technologies Inc. --
32 ------------------------------------------------------------------------------
34 package body GNAT
.Spelling_Checker
is
36 ------------------------
37 -- Is_Bad_Spelling_Of --
38 ------------------------
40 function Is_Bad_Spelling_Of
42 Expect
: String) return Boolean
44 FN
: constant Natural := Found
'Length;
45 FF
: constant Natural := Found
'First;
46 FL
: constant Natural := Found
'Last;
48 EN
: constant Natural := Expect
'Length;
49 EF
: constant Natural := Expect
'First;
50 EL
: constant Natural := Expect
'Last;
53 -- If both strings null, then we consider this a match, but if one
54 -- is null and the other is not, then we definitely do not match
62 -- If first character does not match, then we consider that this is
63 -- definitely not a misspelling. An exception is when we expect a
64 -- letter O and found a zero.
66 elsif Found
(FF
) /= Expect
(EF
)
67 and then (Found
(FF
) /= '0'
68 or else (Expect
(EF
) /= 'o' and then Expect
(EF
) /= 'O'))
72 -- Not a bad spelling if both strings are 1-2 characters long
74 elsif FN
< 3 and then EN
< 3 then
77 -- Lengths match. Execute loop to check for a single error, single
78 -- transposition or exact match (we only fall through this loop if
79 -- one of these three conditions is found).
82 for J
in 1 .. FN
- 2 loop
83 if Expect
(EF
+ J
) /= Found
(FF
+ J
) then
85 -- If both mismatched characters are digits, then we do
86 -- not consider it a misspelling (e.g. B345 is not a
87 -- misspelling of B346, it is something quite different)
89 if Expect
(EF
+ J
) in '0' .. '9'
90 and then Found
(FF
+ J
) in '0' .. '9'
94 elsif Expect
(EF
+ J
+ 1) = Found
(FF
+ J
+ 1)
95 and then Expect
(EF
+ J
+ 2 .. EL
) = Found
(FF
+ J
+ 2 .. FL
)
99 elsif Expect
(EF
+ J
) = Found
(FF
+ J
+ 1)
100 and then Expect
(EF
+ J
+ 1) = Found
(FF
+ J
)
101 and then Expect
(EF
+ J
+ 2 .. EL
) = Found
(FF
+ J
+ 2 .. FL
)
111 -- At last character. Test digit case as above, otherwise we
112 -- have a match since at most this last character fails to match.
114 if Expect
(EL
) in '0' .. '9'
115 and then Found
(FL
) in '0' .. '9'
116 and then Expect
(EL
) /= Found
(FL
)
123 -- Length is 1 too short. Execute loop to check for single deletion
125 elsif FN
= EN
- 1 then
126 for J
in 1 .. FN
- 1 loop
127 if Found
(FF
+ J
) /= Expect
(EF
+ J
) then
128 return Found
(FF
+ J
.. FL
) = Expect
(EF
+ J
+ 1 .. EL
);
132 -- If we fall through then the last character was missing, which
133 -- we consider to be a match (e.g. found xyz, expected xyza).
137 -- Length is 1 too long. Execute loop to check for single insertion
139 elsif FN
= EN
+ 1 then
140 for J
in 1 .. EN
- 1 loop
141 if Found
(FF
+ J
) /= Expect
(EF
+ J
) then
142 return Found
(FF
+ J
+ 1 .. FL
) = Expect
(EF
+ J
.. EL
);
146 -- If we fall through then the last character was an additional
147 -- character, which is a match (e.g. found xyza, expected xyz).
151 -- Length is completely wrong
156 end Is_Bad_Spelling_Of
;
158 end GNAT
.Spelling_Checker
;