Contributor: RENE SCHWIETZKE { From: Rene Schwietzke} program wildcards; {**************************************************************************** * René 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 A* : words with >=1 letters and A at the begin ? : 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 position<>0 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 q<>0 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('Löffler','*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 Übersichten','?*',false),' T'); writeln(wild('Physik in Übersichten','P*??*en',false),' T'); writeln(wild('Alle Physik in Übersichten Physik in Ablagen', '*n Physik*',false),' T'); {Thank's for testing and using.} {René Schwietzke 01-16-1995} end.