code: function () {
  		var self = this,
  			dates = Object.keys(this.parse_tree),
  			lines = [];
  		
  		dates.sort();
  		dates.forEach(function (dy, i) {
  			var times = Object.keys(self.parse_tree[dy]);
  			lines.push(dy);
  			times.sort();
  			times.forEach(function (tm) {
  				var tags = "", maps = "", notes = "", rec;
  				
  				rec = self.parse_tree[dy][tm];
  				if (typeof rec === "string") {
  					notes = rec;
  				} else {
  					if (typeof rec.map !== "undefined" &&
  							rec.map !== false) {
  						maps = [
  							rec.map.project_name,
  							rec.map.task
  						].join(", ") + "; ";
  					}
  					if (typeof rec.tags !== "undefined" &&
  							rec.tags !== false) {
  						tags = rec.tags.join(", ") + "; ";
  					}
  					if (typeof rec.notes !== "undefined") {
  						notes = rec.notes;
  					}
  				}
  
  				lines.push([
  					tm,
  					"; ",
  					tags,
  					maps,
  					notes
  				].join(""));
  			});
  		});
  		
  		return lines.join("\n\n");
  	}
docs: Render parse tree as string.