将Python字典重写为Scala多图（移植代码）？

Question

I'm trying to rewrite a python library to Scala for more compatibility with the new project . The Python version had some inMemoryStorage based on a dict

class InMemoryStorage(BaseStorage):
  def __init__(self, config):
    self.name = 'dict'
    self.storage = dict()

  def keys(self):
    return self.storage.keys()

  def set_val(self, key, val):
    self.storage[key] = val

  def get_val(self, key):
    return self.storage[key]

  def append_val(self, key, val):
    self.storage.setdefault(key, []).append(val)

  def get_list(self, key):
    return self.storage.get(key, [])

My scala version is not quite there yet not sure hot to improve it since I'm new to scala porting it is getting really hard. What am i missing? Is this a close enough rewrite?

class Storage {
  val internalStorage=new HashMap[String, Set[String]] with MultiMap[String, String]

  def keys():Iterable[String]={
    internalStorage.keys
  }

  def set_val(key:String,value:String)={
    internalStorage.addBinding(key,value)
  }

  def get_val( key:String):Set[String]= {
    return internalStorage(key)
  }

  def append_val( key:String, value:String)={
    internalStorage.addBinding(key,value)
  }

  def get_list(key:String):Set[String]={
    internalStorage(key)
  }
}

Answer 1

You are on the right track, the set_val needs to override the initial (key, value) (if present) and start afresh (as seen from python code):

def set_val(key:String,value:String)={
  if (internalStorage.contains(key)) 
    internalStorage.remove(key); // to start fresh
  internalStorage.addBinding(key,value)
}

Also, as the internalStorage is being accessed only using Storage, you might want to make it private .

private[this] val internalStorage=new HashMap[String, Set[String]] with MultiMap[String, String]