Lecture - Imperative Programming TT23, VIII

• Mutable and immutable collections
  • scala.collection.mutable vs scala.collection.immutable
  • Lists share the same static type but the dynamic type can be different
• GUI programming
  • scala-swing
    • Layout
    • Events
    • Drawing
    • Threads

Example code

import scala.swing.

object FirstSwingApp extends SimpleSwingApplication {
	def top = new MainFrame {
		contents = new Label("Hello world")
	}
}

• MainFrame is a subclass of Frame which quits the application when done (e.g. the cross is clicked).
• In match expressions, case Blah which try and match a specific value or type called Blah, but case blah means anything will bind to blah. Can fix by doing

case `blah`

Flashcards

case Blah
case blah
case `blah`

case Blah       // Matches a specific type or value named Blah,
case blah       // Will bind anything to a variable called "blah",
case `blah`     // Matches a specific type or value named blah.