function yyy = parse(buuu)
%***************************************************************
% Parse a Dirac Notation string: Part of the Dirac Package
% syntax:  parse(' <a|b> ',0)  or  parse(' O1=| a >< b | ',0) etc.
% supports exp( anyobject) sqrt( realscalar )
% supports assignments like |b> = | a >< b | c > 
% supports assignments like <b| = <c |b >< a | (equiv. to above)
% if used outside Dirac:
%    you must first define in MATLAB
%          GLOBALIZE= ' '
%***************************************************************
 
    %  This is a patched extensively tested version
    %  It must be soon edited - to replace the patches
    %  July 28th 1995
    %  and Division sign extensions/patches
    %  August 7th 95

    global TESTOUT; TESTOUT = 0;
    
    global GLOBALIZE;
    eval(GLOBALIZE);

 QUOT=setstr(39);
 teststr=buuu;
 blanc=setstr(32);
 NONE=''; Colon=':';

 %remove all double blanks
 while findstr(teststr,[blanc blanc])~=[]
    teststr=strrep(teststr,[blanc blanc],blanc); 
 end
 %remove blanc at beginning and end
 if teststr(length(teststr))==blanc
    teststr=teststr(1:length(teststr)-1) ; 
 end 
 if teststr(1)==blanc
    teststr=teststr(2:length(teststr)) ;
 end    
 %remove all stars
 teststr=strrep(teststr,'*',NONE);
 %replace blancs by :
 teststr=strrep(teststr,blanc,':'); 
 %Replace exp by ^ 
 teststr=strrep(teststr,'exp','^') ;
 % Elimination of blancs where not necessary
   csigns='|<+->()=^/';
   NoOfSigns=length(csigns); %
   for kk=1:NoOfSigns
      teststr=strrep(teststr,[csigns(kk) Colon],csigns(kk));
      teststr=strrep(teststr,[Colon csigns(kk)],csigns(kk));
   end   

   Tleng=length(teststr);
 Oldname=''; %  This is used to check for sin, cos etc ....
 %localize all <||> + - ( ) = ^ :
 
 CONTROLS = sort( [   findstr(teststr,'<') findstr(teststr,'|') ...
 findstr(teststr,'>') findstr(teststr,'+') findstr(teststr,'-') ...
 findstr(teststr,'=') findstr(teststr,'(') findstr(teststr,')') ...
 findstr(teststr,':') findstr(teststr,'^') findstr(teststr,'/')] );

  if(TESTOUT==1)
    teststr
    CONTROLS
  end

  assignment=findstr(teststr,'='); 

% find total number of Dirac Signs
  conts=length(CONTROLS);

if CONTROLS==[]

  yyy=buuu;   

else  
  NotStartControl=0;
  yyy=' ';StarMissing = 0;
  if(  CONTROLS(1) ~= 1 )
    yyy=teststr(1:CONTROLS(1)-1); StarMissing = 1;
    Oldname= teststr(1:CONTROLS(1)-1); 
    NotStartControl=1;
  end 
  if  CONTROLS(conts)~=Tleng
      CONTROLS = [CONTROLS (Tleng+1) ];
      teststr=[teststr ' '];
      conts=conts+1;
  end 
  patchflag=0; ProtectedName= 0; 
  for kk=1:conts-1   % 
    if (length(Oldname)==3 )
      if Oldname=='sin' | Oldname=='cos' 
      ProtectedName=1;
      end
    end 
    if (length(Oldname)==4 )
      if Oldname=='expm' | Oldname=='sqrt'
      ProtectedName=1;
      end
    end      
    OperSign=      teststr(CONTROLS(kk) );
    NextOperSign = teststr(CONTROLS(kk+1) );
     if(CONTROLS(kk+1)-CONTROLS(kk)>1)
        NaME=teststr(CONTROLS(kk)+1:CONTROLS(kk+1)-1);
        Oldname=NaME;
     else
        NaME='';
     end 

     if OperSign=='^'
           yyy = [ yyy 'expm' ];
           ProtectedName=1;  % Patch here too PATCH
     end         

    % two signs after each other  
    if( ( CONTROLS(kk+1)- CONTROLS(kk) ) ==1 )  % two signs after each other
       if( OperSign=='>')              % case >
          if( NextOperSign~='+' & NextOperSign~='-' & ...
              NextOperSign~='=' & NextOperSign~=')' & ...
              NextOperSign~='/'     )
            yyy=[ yyy '*' ];StarMissing = 0;
          end 
       end 
       if( OperSign=='|')              % case |
          if( NextOperSign~='+' & NextOperSign~='-' & ...
              NextOperSign~='=' & NextOperSign~=')' & ...
              NextOperSign~='/'     )
            yyy=[ yyy '*' ]; StarMissing = 0;       
          end
       end
       if( OperSign== '(' & NextOperSign=='|' & ProtectedName~= 1)

               if (kk==1 & NotStartControl==0)
                 yyy=[ yyy OperSign NaME]; StarMissing = 0;
                 patchflag=1;
               else  
                 yyy=[ yyy '*' OperSign NaME]; StarMissing = 0; 
                 patchflag=1;   %PATCHED  HERE
               end    
       else             
        if( OperSign=='+' | OperSign=='-' | OperSign=='=' | ...
            OperSign=='(' | OperSign==')'      )   % case + - = ( ) 
                yyy=[ yyy OperSign ]; StarMissing = 0;
                 if(OperSign~=')' )
                    StartFlag =  1 ;
                    StarMissing = 0;
                  end       
        end    %  
       end   %  PATCH .... 
       if( OperSign== ')' & NextOperSign=='(' )
               yyy=[ yyy '*' ]; StarMissing = 0;
       end 
       if( OperSign== ')' & NextOperSign=='|' )   % NEXT PATCH
               yyy=[ yyy '*' ]; StarMissing = 0;
       end        
       % Division sign patches
       if( ( OperSign== ')' ) & NextOperSign=='/' )
               yyy=[ yyy OperSign ]; StarMissing = 0;
       end
       if( OperSign== '>'  |  OperSign== '|' )...
           & NextOperSign=='/' 
               StarMissing = 0;
       end
       % Other side Division sign patches
       if( ( OperSign== '/' ) & NextOperSign=='(' )
               yyy=[ yyy OperSign ] ;StarMissing = 0;
       end
       if OperSign=='/' ...
          & ( NextOperSign== '<'|  NextOperSign== '|' ) 
               yyy=[ yyy OperSign ]
                StarMissing = 0; 
       end
             % done two signs after each other (there is no name)
             %%%%%%%%%%%%%                   %%%%%%%%%%%%%%%%%%%%%%
     else    % there is a name
    %%%%%%
        if( OperSign=='<')
           if ( StarMissing == 1 )
              yyy=[ yyy '*' ];
              StarMissing = 0;
           end   
           yyy=[ yyy '(' NaME ')' QUOT  ] ;
           % yyy=[ yyy 'conj(' NaME ')' QUOT  ] ;
        end 
        
        if( OperSign=='|' ) 
           if( CONTROLS(kk)== 1 |  StartFlag ==  1) 
             yyy=[ yyy  NaME] ; StarMissing = 1; % if first sign
           else 
             if (patchflag==1 )        
               yyy=[ yyy  NaME] ; StarMissing = 1; % if not first sign
               patchflag=0;
             else
               yyy=[ yyy '*' NaME] ; StarMissing = 1; % if not first sign 
             end  
           end
        end 
        if( OperSign=='+' | OperSign=='-' | ...
            OperSign=='='       )
           yyy=[ yyy OperSign NaME]; StarMissing = 1;       
        end
        if  OperSign=='(' 
           if  ProtectedName== 1 | (kk==1 & NotStartControl==0) ...
              |  StarMissing == 0 %  PATCH AGAIN (TRIPLE)     
              yyy=[ yyy OperSign NaME]; StarMissing = 0; 
              ProtectedName=0;
           else
              yyy=[ yyy '*' OperSign NaME]; StarMissing = 0; 
           end      
        end 
        if  OperSign==':'         
           yyy=[ yyy '*' NaME]; StarMissing = 0;       
        end
        if  OperSign==')'            
              yyy=[ yyy  OperSign '*' NaME];  % additional; fixing
              StarMissing = 0;
        end  
        %  Another Division sign patch
        if  OperSign=='/'
              yyy=[ yyy  OperSign NaME ];
        end  
        StartFlag =0;          
     end  %%%%%%%%%%%%%%%%%% there was a name  %%%%%%%%%%%%%%%%%%
                            %%%%%%%%%%%%%%%%%%
   end   %  for all control signs

   LastOperSign = teststr(CONTROLS(conts) );
   if( LastOperSign==')' )  
     yyy=[ yyy LastOperSign ]  ;
   end 
   if CONTROLS(conts) ~= Tleng 
     yyy=[ yyy  teststr(CONTROLS(conts)+1: Tleng)];
   end 
 % One more patch: equal sign followed by a star
   Tleng=length(yyy); 
   unwant='=*';
   punwant=findstr(yyy,unwant);
   if(length(punwant)>0 )
     yyy=[ yyy(1:punwant(1)) yyy(punwant(1)+2:Tleng)];
   end
 % One more patch: star followed by a star
   Tleng=length(yyy); 
   unwant='**';
   punwant=findstr(yyy,unwant);
   if(length(punwant)>0 )
     yyy=[ yyy(1:punwant(1)) yyy(punwant(1)+2:Tleng)];
   end  
  
   % When the string contains an assignment, pre-pend a blanc (not used)
   if assignment ~= []
      yyy= [ ' ' yyy ];
   end

end
% postprocessing 

 PosConj = findstr(yyy,[ QUOT '=']);
    
  if PosConj~=[]
     Tleng = length(yyy);
     www = yyy(1:PosConj-1);
     www=strrep(www,'(',NONE);
     www=strrep(www,')',NONE);
     www = [www '=(' yyy(PosConj+2: Tleng ) ')' QUOT ];
     yyy = www;
  end