Scala - case match partial string

Question

I have the following:

serv match {

    case \"chat\" => Chat_Server ! Relay_Message(serv)
    case _ => null

}

The problem is that some

Answer 1

In case you want to dismiss any groupings when using regexes, make sure you use a sequence wildcard like _* (as per Scala's documentation).

From the example above:

val Pattern = "(chat.*)".r

serv match {
     case Pattern(_*) => "It's a chat"
     case _ => "Something else"
}

Answer 2

Have the pattern matching bind to a variable and use a guard to ensure the variable begins with "chat"

// msg is bound with the variable serv
serv match {
  case msg if msg.startsWith("chat") => Chat_Server ! Relay_Message(msg)
  case _ => null
}

Answer 3

Use regexes ;)

val Pattern = "(chat.*)".r

serv match {
     case Pattern(chat) => "It's a chat"
     case _ => "Something else"
}

And with regexes you can even easily split parameter and base string:

val Pattern = "(chat)(.*)".r

serv match {
     case Pattern(chat,param) => "It's a %s with a %s".format(chat,param)
     case _ => "Something else"
}