text: /* TODO: in browser attach to DOM; in node use an html parser */
  var HTML_ = (function() {
  	function html_to_sheet(str/*:string*/, _opts)/*:Workbook*/ {
  		var opts = _opts || {};
  		if(DENSE != null && opts.dense == null) opts.dense = DENSE;
  		var ws/*:Worksheet*/ = opts.dense ? ([]/*:any*/) : ({}/*:any*/);
  		var i = str.indexOf("<table"), j = str.indexOf("</table");
  		if(i == -1 || j == -1) throw new Error("Invalid HTML: missing <table> / </table> pair");
  		var rows = str.slice(i, j).split(/(:?<tr[^>]*>)/);
  		var R = -1, C = 0, RS = 0, CS = 0;
  		var range = {s:{r:10000000, c:10000000},e:{r:0,c:0}};
  		var merges = [], midx = 0;
  		for(i = 0; i < rows.length; ++i) {
  			var row = rows[i].trim();
  			if(row.substr(0,3) == "<tr") { ++R; C = 0; continue; }
  			if(row.substr(0,3) != "<td") continue;
  			var cells = row.split("</td>");
  			for(j = 0; j < cells.length; ++j) {
  				var cell = cells[j].trim();
  				if(cell.substr(0,3) != "<td") continue;
  				var m = cell, cc = 0;
  				/* TODO: parse styles etc */
  				while(m.charAt(0) == "<" && (cc = m.indexOf(">")) > -1) m = m.slice(cc+1);
  				while(m.indexOf(">") > -1) m = m.slice(0, m.lastIndexOf("<"));
  				var tag = parsexmltag(cell.slice(0, cell.indexOf(">")));
  				CS = tag.colspan ? +tag.colspan : 1;
  				if((RS = +tag.rowspan)>0 || CS>1) merges.push({s:{r:R,c:C},e:{r:R + (RS||1) - 1, c:C + CS - 1}});
  				/* TODO: generate stub cells */
  				if(!m.length) { C += CS; continue; }
  				m = unescapexml(m).replace(/[\r\n]/g,"");
  				if(range.s.r > R) range.s.r = R;
  				if(range.e.r < R) range.e.r = R;
  				if(range.s.c > C) range.s.c = C;
  				if(range.e.c < C) range.e.c = C;
  				if(opts.dense) {
  					if(!ws[R]) ws[R] = [];
  					if(Number(m) == Number(m)) ws[R][C] = {t:'n', v:+m};
  					else ws[R][C] = {t:'s', v:m};
  				} else {
  					var coord/*:string*/ = encode_cell({r:R, c:C});
  					/* TODO: value parsing */
  					if(Number(m) == Number(m)) ws[coord] = {t:'n', v:+m};
  					else ws[coord] = {t:'s', v:m};
  				}
  				C += CS;
  			}
  		}
  		ws['!ref'] = encode_range(range);
  		return ws;
  	}
  	function html_to_book(str/*:string*/, opts)/*:Workbook*/ {
  		return sheet_to_workbook(html_to_sheet(str, opts), opts);
  	}
  	function make_html_row(ws/*:Worksheet*/, r/*:Range*/, R/*:number*/, o)/*:string*/ {
  		var M = (ws['!merges'] ||[]);
  		var oo = [];
  		for(var C = r.s.c; C <= r.e.c; ++C) {
  			var RS = 0, CS = 0;
  			for(var j = 0; j < M.length; ++j) {
  				if(M[j].s.r > R || M[j].s.c > C) continue;
  				if(M[j].e.r < R || M[j].e.c < C) continue;
  				if(M[j].s.r < R || M[j].s.c < C) { RS = -1; break; }
  				RS = M[j].e.r - M[j].s.r + 1; CS = M[j].e.c - M[j].s.c + 1; break;
  			}
  			if(RS < 0) continue;
  			var coord = encode_cell({r:R,c:C});
  			var cell = o.dense ? (ws[R]||[])[C] : ws[coord];
  			if(!cell || cell.v == null) { oo.push("<td></td>"); continue; }
  			/* TODO: html entities */
  			var w = cell.h || escapexml(cell.w || (format_cell(cell), cell.w) || "");
  			var sp = {};
  			if(RS > 1) sp.rowspan = RS;
  			if(CS > 1) sp.colspan = CS;
  			oo.push(writextag('td', w, sp));
  		}
  		return "<tr>" + oo.join("") + "</tr>";
  	}
  	function sheet_to_html(ws/*:Worksheet*/, opts/*:Sheet2HTMLOpts*/)/*:string*/ {
  		var o = opts || {};
  		var out/*:Array<string>*/ = [];
  		var r = decode_range(ws['!ref']);
  		o.dense = Array.isArray(ws);
  		for(var R = r.s.r; R <= r.e.r; ++R) out.push(make_html_row(ws, r, R, o));
  		return "<html><body><table>" + out.join("") + "</table></body></html>";
  	}
  
  	return {
  		to_workbook: html_to_book,
  		to_sheet: html_to_sheet,
  		_row: make_html_row,
  		from_sheet: sheet_to_html
  	};
  })();
  
  function parse_dom_table(table/*:HTMLElement*/, _opts/*:?any*/)/*:Worksheet*/ {
  	var opts = _opts || {};
  	if(DENSE != null) opts.dense = DENSE;
  	var ws/*:Worksheet*/ = opts.dense ? ([]/*:any*/) : ({}/*:any*/);
  	var rows = table.getElementsByTagName('tr');
  	var range = {s:{r:0,c:0},e:{r:rows.length - 1,c:0}};
  	var merges = [], midx = 0;
  	var R = 0, _C = 0, C = 0, RS = 0, CS = 0;
  	for(; R < rows.length; ++R) {
  		var row = rows[R];
  		var elts = row.children;
  		for(_C = C = 0; _C < elts.length; ++_C) {
  			var elt = elts[_C], v = elts[_C].innerText;
  			for(midx = 0; midx < merges.length; ++midx) {
  				var m = merges[midx];
  				if(m.s.c == C && m.s.r <= R && R <= m.e.r) { C = m.e.c+1; midx = -1; }
  			}
  			/* TODO: figure out how to extract nonstandard mso- style */
  			CS = +elt.getAttribute("colspan") || 1;
  			if((RS = +elt.getAttribute("rowspan"))>0 || CS>1) merges.push({s:{r:R,c:C},e:{r:R + (RS||1) - 1, c:C + CS - 1}});
  			var o = {t:'s', v:v};
  			if(v != null && v.length && !isNaN(Number(v))) o = {t:'n', v:Number(v)};
  			if(opts.dense) { if(!ws[R]) ws[R] = []; ws[R][C] = o; }
  			else ws[encode_cell({c:C, r:R})] = o;
  			if(range.e.c < C) range.e.c = C;
  			C += CS;
  		}
  	}
  	ws['!merges'] = merges;
  	ws['!ref'] = encode_range(range);
  	return ws;
  }
  
  function table_to_book(table/*:HTMLElement*/, opts/*:?any*/)/*:Workbook*/ {
  	return sheet_to_workbook(parse_dom_table(table, opts), opts);
  }
  