Basic protocol for the Buyer-Seller example

The code below is a possible implementation of a process that follows this protocol.

def seller(s: S$State$Init): S$State$Final = s
  .send(B, Descr)
  .send(B, Price)
  .recv(
    (_, _, s) => { println("offer accepted"); s },
    (_, _, s) => { println("offer rejected"); s }
  )

def buyer(s: B$State$Init): B$State$Final = s
  .recv(
    (_, _, s) => s.recv(
      (_, _, s) => s.send(S, Rej) // or s.send(S, Acc)
    )
  )

val pr = new Protocol
pr.run(seller)
pr.run(buyer)

To quickly run this example you can:

• open https://scastie.scala-lang.org to run Scala code online
• Copy the code in the "All" tab of the "Scala APIs" widget and paste it on the Scastie
• Copy the process implementations above and paste it on the bottom of the same Sastie
• Press "Run" to run the process.