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 _ G E N E R I C --
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_Generic is
40 ------------------------
41 -- Is_Bad_Spelling_Of --
42 ------------------------
44 function Is_Bad_Spelling_Of
46 Expect : String_Type) 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;
56 Letter_o : constant Char_Type := Char_Type'Val (Character'Pos ('o'));
57 Digit_0 : constant Char_Type := Char_Type'Val (Character'Pos ('0'));
58 Digit_9 : constant Char_Type := Char_Type'Val (Character'Pos ('9'));
61 -- If both strings null, then we consider this a match, but if one
62 -- is null and the other is not, then we definitely do not match
70 -- If first character does not match, then we consider that this is
71 -- definitely not a misspelling. An exception is when we expect a
72 -- letter O and found a zero.
74 elsif Found (FF) /= Expect (EF)
75 and then (Found (FF) /= Digit_0 or else Expect (EF) /= Letter_o)
79 -- Not a bad spelling if both strings are 1-2 characters long
81 elsif FN < 3 and then EN < 3 then
84 -- Lengths match. Execute loop to check for a single error, single
85 -- transposition or exact match (we only fall through this loop if
86 -- one of these three conditions is found).
89 for J in 1 .. FN - 2 loop
90 if Expect (EF + J) /= Found (FF + J) then
92 -- If both mismatched characters are digits, then we do
93 -- not consider it a misspelling (e.g. B345 is not a
94 -- misspelling of B346, it is something quite different)
96 if Expect (EF + J) in Digit_0 .. Digit_9
97 and then Found (FF + J) in Digit_0 .. Digit_9
101 elsif Expect (EF + J + 1) = Found (FF + J + 1)
102 and then Expect (EF + J + 2 .. EL) = Found (FF + J + 2 .. FL)
106 elsif Expect (EF + J) = Found (FF + J + 1)
107 and then Expect (EF + J + 1) = Found (FF + J)
108 and then Expect (EF + J + 2 .. EL) = Found (FF + J + 2 .. FL)
118 -- At last character. Test digit case as above, otherwise we
119 -- have a match since at most this last character fails to match.
121 if Expect (EL) in Digit_0 .. Digit_9
122 and then Found (FL) in Digit_0 .. Digit_9
123 and then Expect (EL) /= Found (FL)
130 -- Length is 1 too short. Execute loop to check for single deletion
132 elsif FN = EN - 1 then
133 for J in 1 .. FN - 1 loop
134 if Found (FF + J) /= Expect (EF + J) then
135 return Found (FF + J .. FL) = Expect (EF + J + 1 .. EL);
139 -- If we fall through then the last character was missing, which
140 -- we consider to be a match (e.g. found xyz, expected xyza).
144 -- Length is 1 too long. Execute loop to check for single insertion
146 elsif FN = EN + 1 then
147 for J in 1 .. EN - 1 loop
148 if Found (FF + J) /= Expect (EF + J) then
149 return Found (FF + J + 1 .. FL) = Expect (EF + J .. EL);
153 -- If we fall through then the last character was an additional
154 -- character, which is a match (e.g. found xyza, expected xyz).
158 -- Length is completely wrong
163 end Is_Bad_Spelling_Of;
165 end GNAT.Spelling_Checker_Generic;