Is it possible to do anything after a pattern match in a foreach
statement?
I want to do a post match step e.g. to set a variable. I also want to force a Unit return as my foreach
is String => Unit, and by default Scala wants to return the last statement.
Here is some code:
Iteratee.foreach[String](_ match {
case "date" => out.push("Current date: " + new Date().toString + "<br/>")
case "since" => out.push("Last command executed: " + (ctm - last) + "ms before now<br/>")
case unknow => out.push("Command: " + unknown + " not recognized <br/>")
} // here I would like to set "last = ctm" (will be a Long)
)
UPDATED: New code and context. Also new questions added :) They are embedded in the comments.
def socket = WebSocket.using[String] { request =>
// Comment from an answer bellow but what are the side effects?
// By convention, methods with side effects takes an empty argument list
def ctm(): Long = System.currentTimeMillis
var last: Long = ctm
// Command handlers
// Comment from an answer bellow but what are the side effects?
// By convention, methods with side effects takes an empty argument list
def date() = "Current date: " + new Date().toString + "<br/>"
def since(last: Long) = "Last command executed: " + (ctm - last) + "ms before now<br/>"
def unknown(cmd: String) = "Command: " + cmd + " not recognized <br/>"
val out = Enumerator.imperative[String] {}
// How to transform into the mapping strategy given in lpaul7's nice answer.
lazy val in = Iteratee.foreach[String](_ match {
case "date" => out.push(date)
case "since" => out.push(since(last))
case unknown => out.push(unknown)
} // Here I want to update the variable last to "last = ctm"
).mapDone { _ =>
println("Disconnected")
}
(in, out)
}
I don't know what your ctm
is, but you could always do this:
val xs = List("date", "since", "other1", "other2")
xs.foreach { str =>
str match {
case "date" => println("Match Date")
case "since" => println("Match Since")
case unknow => println("Others")
}
println("Put your post step here")
}
Note you should use {}
instead of ()
when you want use a block of code as the argument of foreach().
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