Contributor: RICHARD KOENIG
program wildcards;
{***************************************************************************=
*
* Ren=82 Schwietzke Richard-Koenig-Str. 08 D-04916 Herzberg GERMANY =
*
* =
*
* Internet: rs@informatik.tu-cottbus.de =
*
=
***************************************************************************=
*
* This is my implementation of a simple wildcard recognizer. =
*
* Try it ! =
*
* Please check the correctness, report all bugs and say your opinion. =
*
* =
*
* written in Borland Pascal 7.0 with using of exit, break and continue =
*
=
***************************************************************************=
*
}
uses crt; {only for this demo}
{ * :>= 0 letters
for example:
*A : words with>= 1 letters and A at the end
A*A : words with>= 2 letters and A at the begin and end=20
A* : words with>= 1 letters and A at the begin
=20
? : one letter
Combine it !
See the examples at the end.}
{********** this function returns true if input_word= wilds=
****************}
Function Wild(input_word,wilds:String;upcase_wish:boolean):Boolean;
{looking for next *, returns position and string until position}
function search_next(var wilds:string):word;
var position,position2:word;
begin
position:=pos('*',wilds); {looks for *}
if position0 then wilds:= copy(wilds,1,position-1);
{returns the string}
search_next:= position;
end;
{compares a string with '?' and another,
returns the position of helpwilds in input_word}
function find_part(helpwilds,input_word:string):word;
var q,q2,q3,between:word;
diff:integer;
begin
q:= pos('?',helpwilds);
if q= 0 then
begin
{if no '?' in helpwilds}
find_part:= pos(helpwilds,input_word);
exit;
end;
{'?' in helpwilds}
diff:= length(input_word)-length(helpwilds);
if diff<0 then begin find_part:= 0;exit;end; between:= 0; {now move helpwilds over input_word} for q:= 0 to diff do begin for q2:= 1 to length(helpwilds) do begin if (input_word[q+q2]= helpwilds[q2]) or (helpwilds[q2]= '?') then begin if q2= length(helpwilds) then begin find_part:= q+1;exit;end;end else break; end; end; find_part:= 0; end; {************************** MAIN ******************************************} { this is the mainpart of wild } var cwild,cinput_word:word;{counter for positions} q,lengthhelpwilds:word; maxinput_word,maxwilds:word;{length of input_word and wilds} helpwilds:string; begin wild:= false; {uncomment this for often use with 'wildcardless' wilds} {if wilds= input_word then begin wild:= true;exit;end;} {delete '**', because '**'= '*'} repeat q:= pos('**',wilds); if q0 then
wilds:= copy(wilds,1,q-1)+'*'+copy(wilds,q+2,255);
until q= 0;
{for fast end, if wilds only '*'}
if wilds= '*' then begin wild:= true;exit;end;
maxinput_word:= length(input_word);
maxwilds := length(wilds);
{upcase all letters}
if upcase_wish then
begin
for q:= 1 to maxinput_word do input_word[q]:= upcase(input_word[q]);
for q:= 1 to maxwilds do wilds[q]:= upcase(wilds[q]);
end;
{set initialization}
cinput_word:= 1;cwild:= 1;
wild:= true;
repeat
{equal letters}
if input_word[cinput_word]= wilds[cwild] then
begin
{goto next letter}
inc(cwild);
inc(cinput_word);
continue;
end;
{equal to '?'}
if wilds[cwild]= '?' then
begin
{goto next letter}
inc(cwild);
inc(cinput_word);
continue;
end;
{handling of '*'}
if wilds[cwild]= '*' then
begin
helpwilds:= copy(wilds,cwild+1,maxwilds);{takes the rest of wilds}
q:= search_next(helpwilds);{search the next '*'}
lengthhelpwilds:= length(helpwilds);
if q= 0 then
begin
{no '*' in the rest}
{compare the ends}
if helpwilds= '' then exit;{'*' is the last letter}
{check the rest for equal length and no '?'}
for q:= 0 to lengthhelpwilds-1 do
if (helpwilds[lengthhelpwilds-q]input_word[maxinput_word-q]) and
(helpwilds[lengthhelpwilds-q]'?') then
begin wild:= false;exit;end;
exit;
end;
{handle all to the next '*'}
inc(cwild,1+lengthhelpwilds);
q:= find_part(helpwilds,copy(input_word,cinput_word,255));
if q= 0 then begin wild:= false;exit;end;
cinput_word:= q+lengthhelpwilds;
continue;
end;
wild:= false;exit;
until (cinput_word>maxinput_word) or (cwild>maxwilds);
{no completed evaluation}
if cinput_word<= maxinput_word then wild:= false;
if cwild<= maxwilds then wild:= false;
end;
begin
clrscr;
{examples with the right result 'T' or 'F'}
writeln(wild('Gebauer','G?bauer',false),' T');
writeln(wild('Heiter','*r*s',false),' F');
writeln(wild('L=94ffler','*r*s',false),' F');
writeln(wild('Trinks','*r*s',false),' T');
writeln(wild('Schwietzke','*e*e*',false),' T');
writeln(wild('Endemann','*e*e*',false),' F');
writeln(wild('Schwietzke','Schwietzke',false),' T');
writeln(wild('Schwietzke','*',false),' T');
writeln(wild('Schwietzke','Schwi*',false),' T');
writeln(wild('Schwietzke','*tzke',false),' T');
writeln(wild('Schwietzke','S?hwie*e',false),' T');
writeln(wild('Schwietzke','S*??*e',false),' T');
writeln(wild('Schwietzke','S*e',false),' T');
writeln(wild('Schwietzke','*e',false),' T');
writeln(wild('Schwietzke','S*k*',false),' T');
writeln(wild('Schwietzke','S??w??tzke',false),' T');
writeln(wild('Schwietzke','Sch*?t*ke',false),' T');
writeln(wild('Schwietzke','Sch*k',false),' F');
writeln(wild('Schwietzke','Sch*i?t*k?',false),' T');
writeln(wild('Physik in =9Abersichten','?*',false),' T');
writeln(wild('Physik in =9Abersichten','P*??*en',false),' T');
writeln(wild('Alle Physik in =9Abersichten Physik in Ablagen',
'*n Physik*',false),' T');
{Thank's for testing and using.}
{Ren=82 Schwietzke 01-16-1995}
end.