text: 
  var index = require('indexof')
  
  exports.add = function(name, el){
  	var arr = exports.array(el)
  	if (index(arr, name) < 0) {
  		arr.push(name)
  		el.className = arr.join(' ')
  	}
  }
  
  exports.remove = function(name, el){
  	if (name instanceof RegExp) {
  		return exports.removeMatching(name, el)
  	}
  	var arr = exports.array(el)
  	var i = index(arr, name)
  	if (i >= 0) {
  		arr.splice(i, 1)
  		el.className = arr.join(' ')
  	}
  }
  
  exports.removeMatching = function(re, el){
  	var arr = exports.array(el)
  	for (var i = 0; i < arr.length;) {
  		if (re.test(arr[i])) arr.splice(i, 1)
  		else i++
  	}
  	el.className = arr.join(' ')
  }
  
  exports.toggle = function(name, el){
  	if (exports.has(name, el)) {
  		exports.remove(name, el)
  	} else {
  		exports.add(name, el)
  	}
  }
  
  exports.array = function(el){
  	return el.className.match(/([^\s]+)/g) || []
  }
  
  exports.has =
  exports.contains = function(name, el){
  	return index(exports.array(el), name) >= 0
  }