Scala interactive script for restaurant meal price estimaton

estimation.scala

/*
Example usage
> scala 
:load estimation.scala
meal add i("Burger", 19.0, 3)
meal add i("Burger (v)", 19.0, 1)
meal add i("Salad", 12.22, 4)
ll // prints meal, counts, item indices
setCount(2, 3)  // add 3 salads, not 4
ll

*/

import collection.mutable._

case class Item( price:Double, count:Int, name:String) {
	def prettyPrint:String = s"$name\t\t$price x $count"
}

val order = Buffer[Item]()

def add( n:String, p:Double ) : Unit = order+=Item(p,1,n)
def add( c:Int ):(String,Double)=>Unit = (n:String, p:Double)=>order+=Item(p,c,n)
def rm(c:Int):Unit = order.remove(c)

def setCount( idx:Int, newCount: Int ):Unit = {
	val old = order.remove(idx);
	order.insert(idx, old.copy(count=newCount) )
}

def setPrice(idx: Int, newPrice: Double): Unit = {
	val old = order.remove(idx)
	order.insert(idx, old.copy(price = newPrice))
}

def dump:Unit = order.foreach( i => println(s"meal add i(\"${i.name}\", ${i.price}, ${i.count})"))
def i(n:String, p:Double):Item = Item(p,1,n)
def i(n:String, p:Double, c:Int):Item = Item(p,c,n)
def clear:Unit = order.clear()

object meal {
	infix def add(i:Item):Unit = order+=i
	def add(s:String, p:Double):Unit = order+=Item(p,1,s)
}

def ll:Unit = {
	val longestName = order.map(_.name.length).max

	order.zipWithIndex.foreach( itm => println( String.format(s"%02d %-${longestName}s % 6.02f x %d", itm._2, itm._1.name, itm._1.price, itm._1.count ) )) 
	val sum = order.map( i => i.count*i.price ).sum
	println("-------------------")
	println(String.format("Meal:       % 7.02f", sum) )
	println(String.format("Tax:        % 7.02f", sum*0.07) )
	println(String.format("Tip (12%%):  % 7.02f", sum*0.12) )
	println(String.format("Total:      % 7.02f", sum*1.19) )
	println("-------------------")
}