echoarg.pony

// This is a pony program that will print the first arg provided to the program.

// Every pony program requires an actor called "Main"
actor Main

  // This is a constructor for the Main actor named "create".
  // It is a convention (supported by syntactic sugar) to call constructors "create".
  // In general, a constructor can have any name that begins with a lower case character.
  // However, the Main actor requires its constructor to be called "create".
  // The "=>" denotes the beginning of the constructor body.
  new create(env: Env) =>

    // This is a try block. It means an exception can be thrown.
    // The compiler reqires you to decide if you want to handle or pass on the exception.
    // This program handles the exception.
    try

      // The "env" variable reprents the current environment.
      // The "out" field represents standard out.
      // The "print" method will print the argument and a new line.
      env.out.print(

        // The "args" field is an array of strings: Array[String].
        // The argument is requesting the String at the idnex 1.
        // This is sugary for "env.args.apply(1)".
        // An exception could be thrown if the provided index is out of bounds.
        env.args(1)

      )

    // This block of code is executed when an exception is thrown in the try block.
    else

      // This prints the literal string "oops".
      env.out.print("oops")

    // This ends the "try" block.
    end