function highlight(mfile,options,outfile)
%HIGHLIGHT - Syntax Highlighting of Matlab M-files in HTML, LaTeX, RTF and XML.
%  HIGHLIGHT(MFILE) takes an M-file MFILE in input and writes on disk an HTML
%  file with the same basename ('foo.m' => 'foo.html') adding colored syntax 
%  highlighting on comment, string and Matlab keyword elements.
%  HIGHLIGHT(MFILE,OPTIONS) with OPTIONS being string 'html', 'xhtml', 'tex', 
%  'rtf' or 'xml', allows to choose the output format between HTML, XHTML, LaTeX
%  RTF or XML. The same rule is used to determine the name of the output file.
%  HIGHLIGHT(MFILE,OPTIONS) allows to specify some options in a structure:
%     options.type - Output file type 
%             [ {'html'} | 'tex' | 'rtf' | 'xml' | 'xhtml']
%     options.tabs - Replace '\t' in source code by n white space
%                           [ 0 ... {4}  ... n]
%     options.linenb - Display line number in front of each line [ 0 | {1} ]
%  HIGHLIGHT(MFILE,OPTIONS,OUTFILE) allows to specify the name of the output 
%  file. OUTFILE can also be a file handle. In that case, no header will be 
%  written, only the highlighted Matlab code will be sent to the OUTFILE stream.

%  Output file can be customized (font style, font color, font size, ...):
%     o HTML: use CSS (Cascading Style Sheets) to define 'comment', 'string', 
%       'keyword', 'cont' and 'code' SPAN elements and 'mcode' PRE tag.
%     o LaTeX: packages 'alltt' and 'color' are required, you can modify colors
%       in defining colors 'string', 'comment' and 'keyword' using command
%                      \definecolor{mycolor}{rgb}{a,b,c}
%     o RTF: Colors are defined in the Color Table at the beginning of the
%       document. See Rich Text Format Specifications for more details:
%       <http://msdn.microsoft.com/library/en-us/dnrtfspec/html/rtfspec.asp>
%     o XML: you will find the DTD of the resulting XML file in matlab.dtd
%       You can then use XSL to transform your XML file in what you want.
%       For example, mat2html.xsl transforms your XML file in HTML as it would
%       be if you would have used highlight.m to to so.
%       On Matlab 6.5, the command is:
%               xslt highlight.xml mat2html.xsl highlight.html
%       On Linux, using libxslt <http://xmlsoft.org/XSLT/>, the command is: 
%               xsltproc -o highlight.html mat2html.xsl highlight.xml

%  Copyright (C) 2003 Guillaume Flandin <Guillaume@artefact.tk>
%  $Revision: 1.1 $Date: 2010/02/24 10:14:32 $

%  This program is free software; you can redistribute it and/or
%  modify it under the terms of the GNU General Public License
%  as published by the Free Software Foundation; either version 2
%  of the License, or any later version.
% 
%  This program is distributed in the hope that it will be useful,
%  but WITHOUT ANY WARRANTY; without even the implied warranty of
%  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
%  GNU General Public License for more details.
% 
%  You should have received a copy of the GNU General Public License
%  along with this program; if not, write to the Free Software
%  Foundation Inc, 59 Temple Pl. - Suite 330, Boston, MA 02111-1307, USA.

% Suggestions for improvement and fixes are always welcome, although no
% guarantee is made whether and when they will be implemented.
% Send requests to Guillaume@artefact.tk

% TODO % Improve distinction between 'end' keyword and array subscript
% TODO % Smart indentation is *very* buggy (unusable => undocumented)
% TODO % Handle wrap mode for long lines in LaTeX mode (and in HTML)
% TODO % Improve the XSL transformer from XML to LaTeX

%- Set up options
error(nargchk(1,3,nargin));

opt = struct('type',   'html', ...
			 'tabs',   4, ...
             'linenb', 1, ...
			 'indent', 0);
if nargin >= 2
	if isstruct(options)
		names = fieldnames(options);
		for i=1:length(names)
			opt = setfield(opt,names{i},getfield(options,names{i}));
		end
	elseif ischar(options)
		opt.type = options;
	else
		error('Bad input argument.');
	end
end
if strcmp(lower(opt.type),'latex'), opt.type = 'tex'; end
if strcmp(lower(opt.type),'xml'), opt.linenb = 1; end

%- If no output filename is provided, one is chosen according to mfile
if nargin < 3
	[pathstr, name, ext] = fileparts(mfile);
	outfile = fullfile(pathstr, [name, '.' lower(opt.type)]);
end

%- If an output filename is provided, a standard header is created
if ischar(outfile)
	outfid = fopen(outfile,'wt');
	if outfid == -1
		error(sprintf('Cannot open ',outfile));
	end
	feval([lower(opt.type) '_file_start'],outfid,mfile);
%- Otherwise a file handle is provided
else
	outfid = outfile;
end

%- Open the Matlab mfile to be highlighted
mfid = fopen(mfile,'rt');
if mfid == -1
	error(sprintf('Cannot open ',mfile));
end

%- Write the syntax highlighted mfile code in the output file
write_highlighted_code(mfid,outfid,opt)

%- Close the Matlab mfile and potentially the output file
fclose(mfid);
if ischar(outfile), 
	feval([lower(opt.type) '_file_end'],outfid);
	fclose(outfid); 
end

%===============================================================================
function write_highlighted_code(mfid,outfid,opt)
	matlabKeywords = getMatlabKeywords;
	mKeySort       = getMatlabKeywordsSorted;
	out_format     = feval([lower(opt.type) '_format']);
	strtok_delim   = sprintf(' \t\n\r(){}[]<>+-*~!|\\@&/.,:;="''%');
	
	fprintf(outfid,out_format.pre_start);
	nbline = 1;
	nbblanks = 0;
	flagnextline = 0;
	while 1
		tline = fgetl(mfid);
		if ~ischar(tline), break, end
		tline = feval([lower(opt.type) '_special_char'],horztab(tline,opt.tabs));
		%- Display the line number at each line
		if opt.linenb
			fprintf(outfid,out_format.nb_line,nbline);
			nbline = nbline + 1;
		end
		%- Remove blanks at the beginning of the line
		if opt.indent
			tline = fliplr(deblank(fliplr(tline)));
		end
		nbblanks = nbblanks + flagnextline;
		flagnextline = 0;
		%- Split code into meaningful chunks
		splitc = splitcode(tline);
		newline = '';
		for i=1:length(splitc)
			if isempty(splitc{i})
			elseif splitc{i}(1) == ''''
				newline = [newline sprintf(out_format.string,splitc{i})];
			elseif splitc{i}(1) == '%'
				newline = [newline sprintf(out_format.comment,splitc{i})];
			elseif ~isempty(strmatch('...',splitc{i}))
				newline = [newline sprintf(out_format.cont,'...')];
				if ~isempty(splitc{i}(4:end))
					newline = [newline sprintf(out_format.comment,splitc{i}(4:end))];
				end
			else
				%- Look for Matlab keywords
				r = splitc{i};
				stringcode = '';
				while 1
					[t,r,q] = strtok(r,strtok_delim);
					stringcode = [stringcode q];
					if isempty(t), break, end;
					isNextIncr  = any(strcmp(t,mKeySort.nextincr));
					isNextIncr2 = any(strcmp(t,mKeySort.nextincr2));
					isCurrDecr  = any(strcmp(t,mKeySort.currdecr));
					isNextDecr  = any(strcmp(t,mKeySort.nextdecr));
					isOther     = any(strcmp(t,mKeySort.other));
					if isNextDecr % if strcmp(t,'end')
						% 'end' is keyword or array subscript ?
						rr = fliplr(deblank(fliplr(r)));
						icomma = strmatch(',',rr);
						isemicolon = strmatch(';',rr);
						if ~(isempty(rr) | ~isempty([icomma isemicolon]))
							isNextDecr = 0;
						else
							nbblanks = nbblanks - 1;
							flagnextline = flagnextline + 1;
						end
						% TODO % false detection of a([end,1])
					end
					if isNextIncr, flagnextline = flagnextline + 1; end
					if isNextIncr2, flagnextline = flagnextline + 2; end
					if isNextDecr, flagnextline = flagnextline - 1; end
					if isCurrDecr, nbblanks = nbblanks - 1; end
					% if any(strcmp(t,matlabKeywords))
					if isNextIncr | isNextIncr2 |isCurrDecr | isNextDecr | isOther
						if ~isempty(stringcode)
							newline = [newline sprintf(out_format.code,stringcode)];
							stringcode = '';
						end
						newline = [newline sprintf(out_format.keyword,t)];
					else
						stringcode = [stringcode t];
					end
				end
				if ~isempty(stringcode)
					newline = [newline sprintf(out_format.code,stringcode)];
				end
			end
		end
		if ~opt.indent, nbblanks = 0; end
		%- Print the syntax highlighted line
		fprintf(outfid,out_format.line,[blanks(nbblanks*opt.tabs) newline]);
	end
	fprintf(outfid,out_format.pre_end);

%===============================================================================
%                                  HTML FORMAT                                 %
%===============================================================================
function html_file_start(fid,mfile)
	fprintf(fid,[ ...
	'<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"\n' ...
    '\t"http://www.w3.org/TR/REC-html40/loose.dtd">\n' ...
	'<html>\n<head>\n<title>%s</title>\n' ...
	'<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">\n' ...
	'<meta name="generator" content="highlight.m &copy; 2003 Guillaume Flandin">\n' ...
	'<style type="text/css">\n' ...
	'  .comment {color: #228B22;}\n' ...
	'  .string {color: #B20000;}\n' ...
	'  .keyword, .cont {color: #0000FF;}\n' ...
	'  .cont {text-decoration: underline;}\n' ...
	'  .code {color: #000000;}\n' ...
	'</style>\n' ...
	'</head>\n<body>\n'],mfile);

%-------------------------------------------------------------------------------
function html_file_end(fid)
	fprintf(fid,'\n</body>\n</html>');

%-------------------------------------------------------------------------------
function format = html_format
	format.string    = '<span class="string">%s</span>';
	format.comment   = '<span class="comment">%s</span>';
	format.code      = '%s'; %'<span class="code">%s</span>';
	format.keyword   = '<span class="keyword">%s</span>';
	format.cont      = '<span class="cont">%s</span>';
	format.pre_start = '<pre class="mcode">';
	format.pre_end   = '</pre>\n';
	format.nb_line   = '%04d ';
	format.line      = '%s\n';

%-------------------------------------------------------------------------------
function str = html_special_char(str)
	%- See http://www.w3.org/TR/html4/charset.html#h-5.3.2
	str = strrep(str,'&','&amp;');
	str = strrep(str,'<','&lt;');
	str = strrep(str,'>','&gt;');
	str = strrep(str,'"','&quot;');

%===============================================================================
%                                  XHTML FORMAT                                %
%===============================================================================
function xhtml_file_start(fid,mfile)
	fprintf(fid,[ ...
	'<?xml version="1.0"?>\n' ...
	'<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" ' ...
	'"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">\n' ...
	'<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en">\n' ...
	'<head>\n<title>%s</title>\n' ...
	'<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />\n' ...
	'<meta name="generator" content="highlight.m &copy; 2003 Guillaume Flandin" />\n' ...
	'<style type="text/css">\n' ...
	'  .comment {color: #228B22;}\n' ...
	'  .string {color: #B20000;}\n' ...
	'  .keyword, .cont {color: #0000FF;}\n' ...
	'  .cont {text-decoration: underline;}\n' ...
	'  .code {color: #000000;}\n' ...
	'</style>\n' ...
	'</head>\n<body>\n'],mfile);

%-------------------------------------------------------------------------------
function xhtml_file_end(fid)
	fprintf(fid,'\n</body>\n</html>');

%-------------------------------------------------------------------------------
function format = xhtml_format
	format.string    = '<span class="string">%s</span>';
	format.comment   = '<span class="comment">%s</span>';
	format.code      = '%s'; %'<span class="code">%s</span>';
	format.keyword   = '<span class="keyword">%s</span>';
	format.cont      = '<span class="cont">%s</span>';
	format.pre_start = '<pre class="mcode">';
	format.pre_end   = '</pre>\n';
	format.nb_line   = '%04d ';
	format.line      = '%s\n';

%-------------------------------------------------------------------------------
function str = xhtml_special_char(str)
	%- See http://www.w3.org/TR/html4/charset.html#h-5.3.2
	str = strrep(str,'&','&amp;');
	str = strrep(str,'<','&lt;');
	str = strrep(str,'>','&gt;');
	str = strrep(str,'"','&quot;');


%===============================================================================
%                                   XML FORMAT                                 %
%===============================================================================
function xml_file_start(fid,mfile)
	fprintf(fid,[ ...
	'<?xml version="1.0" encoding="iso-8859-1" ?>\n' ...
	'<!DOCTYPE mfile SYSTEM "matlab.dtd">\n' ...
	'<mfile name="%s">\n'],mfile);

%-------------------------------------------------------------------------------
function xml_file_end(fid)
	fprintf(fid,'</mfile>');

%-------------------------------------------------------------------------------
function format = xml_format
	format.string    = '<string>%s</string>';
	format.comment   = '<comment>%s</comment>';
	format.code      = '%s'; %'<code>%s</code>';
	format.keyword   = '<keyword>%s</keyword>';
	format.cont      = '<cont>%s</cont>';
	format.pre_start = '';
	format.pre_end   = '';
	format.nb_line   = '<line nb="%04d ">';
	format.line      = '%s</line>\n';

%-------------------------------------------------------------------------------
function str = xml_special_char(str)
	%- See http://www.w3.org/TR/REC-xml#sec-predefined-ent
	str = strrep(str,'&','&amp;');
	str = strrep(str,'<','&lt;');
	str = strrep(str,'>','&gt;');
	str = strrep(str,'"','&quot;');
	%str = strrep(str,'''','&apos;');
	
%===============================================================================
%                                  LaTeX FORMAT                                %
%===============================================================================
function tex_file_start(fid,mfile)
	fprintf(fid,['\\documentclass[a4paper,10pt]{article}\n' ...
				 '    \\usepackage{alltt}\n' ...
				 '    \\usepackage{color}\n' ...
				 '    \\usepackage{fullpage}\n' ...
				 '    \\definecolor{string}{rgb}{0.7,0.0,0.0}\n' ...
				 '    \\definecolor{comment}{rgb}{0.13,0.54,0.13}\n' ...
				 '    \\definecolor{keyword}{rgb}{0.0,0.0,1.0}\n' ...
				 '    \\title{%s}\n' ...
				 '    \\author{\\textsc{Matlab}, The Mathworks, Inc.}\n' ...
				 '\\begin{document}\n' ...
				 '\\maketitle\n'],mfile);

%-------------------------------------------------------------------------------
function tex_file_end(fid)
	fprintf(fid,'\\end{document}');

%-------------------------------------------------------------------------------
function format = tex_format
	format.string    = '\\textcolor{string}{%s}';
	format.comment   = 'textcolor{comment}{%s}'; % '%' has been replaced by '\%'
	format.code      = '%s';
	format.keyword   = '\\textcolor{keyword}{%s}';
	format.cont      = '\\textcolor{keyword}{\\underline{%s}}';
	format.pre_start = '\\begin{alltt}\n';
	format.pre_end   = '\\end{alltt}\n';
	format.nb_line   = '%04d ';
	format.line      = '%s\n';

%-------------------------------------------------------------------------------
function str = tex_special_char(str)
	% Special characters: # $ % & ~ _ ^ \ { }
	str = strrep(str,'\','\(\backslash\)'); % $\backslash$ or \textbackslash or \verb+\+
	str = strrep(str,'#','\#');
	str = strrep(str,'$','\$');
	str = strrep(str,'%','\%');
	str = strrep(str,'&','\&');
	str = strrep(str,'_','\_');
	str = strrep(str,'{','\{');
	str = strrep(str,'}','\}');
	str = strrep(str,'^','\^{}');
	str = strrep(str,'~','\~{}'); % or \textasciitilde

%===============================================================================
%                                   RTF FORMAT                                 %
%===============================================================================
function rtf_file_start(fid,mfile)
	fprintf(fid,['{\\rtf1\\ansi\n\n' ...
				 '{\\fonttbl{\\f0\\fmodern\\fcharset0\\fprq1 Courier New;}}\n\n' ...
				 '{\\colortbl;\n' ...
				 '\\red0\\green0\\blue0;\n' ...
				 '\\red0\\green0\\blue255;\n' ...
				 '\\red33\\green138\\blue33;\n' ...
				 '\\red178\\green0\\blue0;}\n\n' ...
				 '{\\info{\\title %s}\n' ...
				 '{\\author HighLight.m Copyright 2003}\n' ...
				 '{\\creatim\\yr%s\\mo%s\\dy%s}' ...
				 '{\\*\\manager Guillaume Flandin}\n' ...
				 '{\\*\\company Artefact.tk}\n' ...
				 '{\\*\\hlinkbase http://www.madic.org/download/' ... 
				 'matlab/highlight/}}\n\n'],mfile,...
				 datestr(date,'yyyy'),datestr(date,'mm'),datestr(date,'dd'));

%-------------------------------------------------------------------------------
function rtf_file_end(fid)
	fprintf(fid,'}');

%-------------------------------------------------------------------------------
function format = rtf_format
	format.string    = '{\\cf4 %s}';
	format.comment   = '{\\cf3 %s}';
	format.code      = '{%s}';
	format.keyword   = '{\\cf2 %s}';
	format.cont      = '{\\cf2 %s}';
	format.pre_start = '{\\f0\\fs16{';
	format.pre_end   = '}}';
	format.nb_line   = '{%04d }';
	format.line      = '%s\n\\par ';

%-------------------------------------------------------------------------------
function str = rtf_special_char(str)
	str = strrep(str,'\','\\');
	str = strrep(str,'{','\{');
	str = strrep(str,'}','\}');

%===============================================================================
%                                 MATLAB KEYWORDS                              %
%===============================================================================
function matlabKeywords = getMatlabKeywords
	%matlabKeywords = iskeyword; % Matlab R13
	matlabKeywords = {'break', 'case', 'catch', 'continue', 'elseif', 'else',...
					  'end', 'for', 'function', 'global', 'if', 'otherwise', ...
					  'persistent', 'return', 'switch', 'try', 'while'};
					  
%-------------------------------------------------------------------------------
function mKeySort = getMatlabKeywordsSorted
	mKeySort.nextincr = {'for', 'while', 'if', 'else', 'elseif', ...
						 'case', 'otherwise', 'try', 'catch'};
	mKeySort.nextincr2 = {'switch'};
	mKeySort.currdecr = {'else', 'elseif', 'case', 'otherwise', 'catch'};
	mKeySort.nextdecr = {'end'};
	mKeySort.other    = {'break', 'continue', 'function', 'global', ...
						 'persistent', 'return'};

%===============================================================================
%                               HANDLE TAB CHARACTER                           %
%===============================================================================
function str = horztab(str,n)
	%- For browsers, the horizontal tab character is the smallest non-zero 
	%- number of spaces necessary to line characters up along tab stops that are
	%- every 8 characters: behaviour obtained when n = 0.
	if n > 0
		str = strrep(str,sprintf('\t'),blanks(n));
	end

%===============================================================================
%                                MATLAB CODE PARSER                            %
%===============================================================================
function splitc = splitcode(code)
	%Split a line of  Matlab code in string, comment and other

	%- Label quotes in {'transpose', 'beginstring', 'midstring', 'endstring'}
	iquote = findstr(code,'''');
	quotetransp = [double('_''.)}]') ...
				   double('A'):double('Z') ...
				   double('0'):double('9') ...
				   double('a'):double('z')];
	flagstring = 0;
	flagdoublequote = 0;
	jquote = [];
	for i=1:length(iquote)
		if ~flagstring
			if iquote(i) > 1 & any(quotetransp == double(code(iquote(i)-1)))
				% => 'transpose';
			else
				% => 'beginstring';
				jquote(size(jquote,1)+1,:) = [iquote(i) length(code)];
				flagstring = 1;
			end
		else % if flagstring
			if flagdoublequote | ...
			   (iquote(i) < length(code) & strcmp(code(iquote(i)+1),''''))
				% => 'midstring';
				flagdoublequote = ~flagdoublequote;
			else
				% => 'endstring';
				jquote(size(jquote,1),2) = iquote(i);
				flagstring = 0;
			end
		end
	end

	%- Find if a portion of code is a comment
	ipercent = findstr(code,'%');
	jpercent = [];
	for i=1:length(ipercent)
		if isempty(jquote) | ...
		   ~any((ipercent(i) > jquote(:,1)) & (ipercent(i) < jquote(:,2)))
			jpercent = [ipercent(i) length(code)];
			break;
		end
	end

	%- Find continuation punctuation '...'
	icont = findstr(code,'...');
	for i=1:length(icont)
		if (isempty(jquote) | ...
			~any((icont(i) > jquote(:,1)) & (icont(i) < jquote(:,2)))) & ...
			(isempty(jpercent) | ...
			icont(i) < jpercent(1))
			jpercent = [icont(i) length(code)];
			break;
		end
	end

	%- Remove strings inside comments
	if ~isempty(jpercent) & ~isempty(jquote)
		jquote(find(jquote(:,1) > jpercent(1)),:) = [];
	end

	%- Split code in a cell array of strings
	icode = [jquote ; jpercent];
	splitc = {};
	if isempty(icode)
		splitc{1} = code;
	elseif icode(1,1) > 1
		splitc{1} = code(1:icode(1,1)-1);
	end
	for i=1:size(icode,1)
		splitc{end+1} = code(icode(i,1):icode(i,2));
		if i < size(icode,1) & icode(i+1,1) > icode(i,2) + 1
			splitc{end+1} = code((icode(i,2)+1):(icode(i+1,1)-1));
		elseif i == size(icode,1) & icode(i,2) < length(code)
			splitc{end+1} = code(icode(i,2)+1:end);
		end
	end
	  
%===============================================================================
%                           MODIFIED VERSION OF STRTOK                         %
%===============================================================================
function [token, remainder, quotient] = strtok(string, delimiters)
% Modified version of STRTOK to also return the quotient
% string = [quotient token remainder]
%STRTOK Find token in string.
%   STRTOK(S) returns the first token in the string S delimited
%   by "white space".   Any leading white space characters are ignored.
%
%   STRTOK(S,D) returns the first token delimited by one of the 
%   characters in D.  Any leading delimiter characters are ignored.
%
%   [T,R] = STRTOK(...) also returns the remainder of the original
%   string.
%   If the token is not found in S then R is an empty string and T
%   is same as S. 
%
%   Copyright 1984-2002 The MathWorks, Inc. 
%   $Revision: 1.1 $  $Date: 2010/02/24 10:14:32 $

token = []; remainder = []; quotient = string;

len = length(string);
if len == 0
    return
end

if (nargin == 1)
    delimiters = [9:13 32]; % White space characters
end

i = 1;
while (any(string(i) == delimiters))
    i = i + 1;
    if (i > len), return, end
end
start = i;
while (~any(string(i) == delimiters))
    i = i + 1;
    if (i > len), break, end
end
finish = i - 1;

token = string(start:finish);

if (nargout >= 2)
    remainder = string(finish + 1:length(string));
end

if (nargout == 3 & start > 1)
	quotient = string(1:start-1);
else
	quotient = [];
end