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) 1998-2007, 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 pragma Warnings (Off);
38 package body GNAT.Spelling_Checker is
40 ------------------------
41 -- Is_Bad_Spelling_Of --
42 ------------------------
44 function Is_Bad_Spelling_Of
46 Expect : String) return Boolean
48 FN : constant Natural := Found'Length;
49 FF : constant Natural := Found'First;
50 FL : constant Natural := Found'Last;
52 EN : constant Natural := Expect'Length;
53 EF : constant Natural := Expect'First;
54 EL : constant Natural := Expect'Last;
57 -- If both strings null, then we consider this a match, but if one
58 -- is null and the other is not, then we definitely do not match
66 -- If first character does not match, then we consider that this is
67 -- definitely not a misspelling. An exception is when we expect a
68 -- letter O and found a zero.
70 elsif Found (FF) /= Expect (EF)
71 and then (Found (FF) /= '0'
72 or else (Expect (EF) /= 'o' and then Expect (EF) /= 'O'))
76 -- Not a bad spelling if both strings are 1-2 characters long
78 elsif FN < 3 and then EN < 3 then
81 -- Lengths match. Execute loop to check for a single error, single
82 -- transposition or exact match (we only fall through this loop if
83 -- one of these three conditions is found).
86 for J in 1 .. FN - 2 loop
87 if Expect (EF + J) /= Found (FF + J) then
89 -- If both mismatched characters are digits, then we do
90 -- not consider it a misspelling (e.g. B345 is not a
91 -- misspelling of B346, it is something quite different)
93 if Expect (EF + J) in '0' .. '9'
94 and then Found (FF + J) in '0' .. '9'
98 elsif Expect (EF + J + 1) = Found (FF + J + 1)
99 and then Expect (EF + J + 2 .. EL) = Found (FF + J + 2 .. FL)
103 elsif Expect (EF + J) = Found (FF + J + 1)
104 and then Expect (EF + J + 1) = Found (FF + J)
105 and then Expect (EF + J + 2 .. EL) = Found (FF + J + 2 .. FL)
115 -- At last character. Test digit case as above, otherwise we
116 -- have a match since at most this last character fails to match.
118 if Expect (EL) in '0' .. '9'
119 and then Found (FL) in '0' .. '9'
120 and then Expect (EL) /= Found (FL)
127 -- Length is 1 too short. Execute loop to check for single deletion
129 elsif FN = EN - 1 then
130 for J in 1 .. FN - 1 loop
131 if Found (FF + J) /= Expect (EF + J) then
132 return Found (FF + J .. FL) = Expect (EF + J + 1 .. EL);
136 -- If we fall through then the last character was missing, which
137 -- we consider to be a match (e.g. found xyz, expected xyza).
141 -- Length is 1 too long. Execute loop to check for single insertion
143 elsif FN = EN + 1 then
144 for J in 1 .. EN - 1 loop
145 if Found (FF + J) /= Expect (EF + J) then
146 return Found (FF + J + 1 .. FL) = Expect (EF + J .. EL);
150 -- If we fall through then the last character was an additional
151 -- character, which is a match (e.g. found xyza, expected xyz).
155 -- Length is completely wrong
160 end Is_Bad_Spelling_Of;
162 end GNAT.Spelling_Checker;