christopherh@1: %
christopherh@1: % PARSENOTE
christopherh@1: % 
christopherh@1: % [natural, accidentals, success, errormessage] = parsenote(note, {verbose})
christopherh@1: % 
christopherh@1: % Parse a note to a natural character value and a number of accidentals
christopherh@1: % if accidentals is positive it denotes number of sharps,
christopherh@1: % if it is negative it denotes number of flats.
christopherh@1: %
christopherh@1: % Success = 1 if symbols parsed correctly, 0 otherwise.
christopherh@1: %
christopherh@1: % If optional argument 'verbose' is 1, function prints any errormessage to 
christopherh@1: % the screen.
christopherh@1: % 
christopherh@1: % returns:  natural     (char)
christopherh@1: %           accidentals (integer) 
christopherh@1: %           success     (boolean)
christopherh@1: %           errormessage (string)
christopherh@1: %
christopherh@1: % Author: Christopher Harte, March 2009
christopherh@1: % 
christopherh@1: % Copyright: Centre for Digital Music, Queen Mary University of London 2005 
christopherh@1: %
christopherh@1: % This file is part of the C4DM Chord Toolkit V2.0  
christopherh@1: %
christopherh@1: % The C4DM Chord Toolkit is free software; you can redistribute it and/or 
christopherh@1: % modify it under the terms of the GNU General Public License as published 
christopherh@1: % by the Free Software Foundation; either version 2 of the License, or
christopherh@1: % (at your option) any later version.
christopherh@1: %
christopherh@1: % The C4DM Chord Toolkit is distributed in the hope that it will be useful,
christopherh@1: % but WITHOUT ANY WARRANTY; without even the implied warranty of
christopherh@1: % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
christopherh@1: % GNU General Public License for more details.
christopherh@1: %
christopherh@1: % You should have received a copy of the GNU General Public License
christopherh@1: % along with the C4DM Toolkit; if not, write to the Free Software
christopherh@1: % Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
christopherh@1: 
christopherh@1: %
christopherh@1: function [natural,accidentals,success, errormessage] = parsenote(note, verbose)
christopherh@1: 
christopherh@1: if nargin < 2
christopherh@1:     verbose = 0;
christopherh@1: end
christopherh@1: 
christopherh@1: errormessage = '';
christopherh@1: 
christopherh@1: ilength = length(note);
christopherh@1: 
christopherh@1: accidentals = 0;
christopherh@1: natural = [];
christopherh@1: success=1;
christopherh@1: 
christopherh@1: index = 1;
christopherh@1: 
christopherh@1: if (isempty(note))  % if we have been passed an empty string
christopherh@1:     success=0;
christopherh@1: 
christopherh@1: else  % parse the note string
christopherh@1:   
christopherh@1:     switch(note(index))
christopherh@1: 
christopherh@1:         case {'A','B','C','D','E','F','G'}
christopherh@1: 
christopherh@1:             %first character should be a natural
christopherh@1:             natural = note(index);
christopherh@1:             index= index+1;
christopherh@1: 
christopherh@1:             %remaining characters should be sharps or flats
christopherh@1:             while index <= ilength
christopherh@1: 
christopherh@1:                 switch note(index)
christopherh@1: 
christopherh@1:                     case 'b' % FLAT
christopherh@1:                         accidentals = accidentals - 1; %decrement accidental count
christopherh@1:                         index = index + 1;
christopherh@1: 
christopherh@1:                     case '#' % SHARP
christopherh@1:                         accidentals = accidentals + 1; %increment accidental count
christopherh@1:                         index = index + 1;
christopherh@1: 
christopherh@1:                     otherwise
christopherh@1:                         % if neither of the above then the note is incorrect
christopherh@1:                         success=0;
christopherh@1:                         index = ilength+1;
christopherh@1:                 end
christopherh@1:             end
christopherh@1: 
christopherh@1:         otherwise
christopherh@1:             success=0;        
christopherh@1:     end
christopherh@1: end
christopherh@1:     
christopherh@1: if(success==0) % correct note therefore return success = 1 
christopherh@1:     % if not an integer then the note string is incorrect
christopherh@1:     errormessage = sprintf(['Error in parsenote: Unrecognised note "' note '"\n']); 
christopherh@1:     
christopherh@1:     if verbose ==1
christopherh@1:         fprintf(1,errormessage);
christopherh@1:     end
christopherh@1: end