Tim Gent timgent

Recursion and Trampolines in Scala

Recursion is beautiful. As an example, let's consider this perfectly acceptable example of defining the functions even and odd in Scala, whose semantics you can guess:

def even(i: Int): Boolean = i match {
  case 0 => true
  case _ => odd(i - 1)
}

def odd(i: Int): Boolean = i match {

	# We'll be installing Homebrew in the /opt directory.
	cd /opt

	# Create a directory for Homebrew. This requires root permissions.
	sudo mkdir homebrew

	# Make us the owner of the directory so that we no longer require root permissions.
	sudo chown -R $(whoami) /opt/homebrew

	# Download and unzip Homebrew. This command can be found at https://docs.brew.sh/Installation.