CODEWITHSUNDEEP
scala
frazman
frazman

Reputation: 33293

Behavior based on condition mentioned by user in scala?

I have an object Foo

object Foo extends RegexParsers{
  def apply(s:String): Array[String] = parseAll(record, line) match {
       // some logic 
      }
   def record = repsep(mainToken, ",")
   // some more code
   def unquotes = "[^,]+".r 
}

Now this is pretty hardcoded for comma separated string..

I want to basically modify this function to basically account for another case (tab seperated)..

For which the following code works

object Foo extends RegexParsers{
      def apply(s:String): Array[String] = parseAll(record, line) match {
           // some logic 
          }
       def record = repsep(mainToken, "\t") // change here
       // some more code
       def unquotes = "[^\t]+".r  // change here
    }

Just two changes...

How do I merge these two changes.. where I can take this delimiter as an argument.. (default argument comma)... and then based on that.. execute the required code.. ?? Thanks

Upvotes: 0

Views: 61

Answers (2)

Andreas Neumann
Andreas Neumann

Reputation: 10904

A solution by just adding a var.

This would also work:

object Foo extends RegexParsers{
  // make sep a var
  var sep : String = ","
  def apply(s:String): Array[String] = parseAll(record, line) match {
     // some logic 
  }
  def record = repsep(mainToken, sep)
  // some more code
  def unquotes = ("[^" + sep + "]+").r 
}

For changing the separator just do:

Foo.sep = "\t"

But beware no you have added mutable State and you could run in problems when the code is run asynchronously or in parallel.

Upvotes: 1

Jesper
Jesper

Reputation: 206926

You could make Foo a class instead of an object, and pass the desired separator character as a constructor argument.

class Foo(separator: Char) extends RegexParsers {

  def apply(s:String): Array[String] = parseAll(record, line) match {
    // some logic 
  }

  def record = repsep(mainToken, separator.toString)

  def unquotes = ("[^" + separator + "]+").r
}

Then use it by making the appropriate instance:

// Parser that uses comma as the separator
val foo1 = new Foo(',')

// Parser that uses tab as the separator
val foo2 = new Foo('\t')

Upvotes: 2

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