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Sequence:

• one learns the use of the seq instruction in SugarCubes;
• in SugarCubes sequence of atomic actions gives a global atomic action;
• this example uses print, println, printError, printlnError instructions;
• this example shows also the use of standard streams in reactive machine (not yet fully implemented).
• use of an empty machine to detect termination of the whole reactive program added in it.
• use of run method of a reactive machine (inherited from the Runnable interface).

This example illustrates the use of the sequence primitive. During one instant, one puts atomic actions (print actions in this case) in sequence.

import inria.meije.rc.sugarcubes.*;

public class Short_Sequence
{
    public static void main(final String[] args){
        final Program p = SC.seq(
                                 SC.println("Hello World!")
                                 , SC.print("This program shows ")
                                 , SC.printError("sequences ")
                                 , SC.print("of printed ")
                                 , SC.printlnError("messages!")
                                 );
        final Machine machine = SC.emptyMachine(p);
// One uses the run method on the reactive machine which makes the machine react
// cyclically until the whole program has finished. The run method then stops
// and the reactive machine is then no more useable. In our case only one
// reaction is computed.
        machine.run();
    }
}

A reactive Machine in SugarCubes also implements the Runnable intefarce of standard Java. So it implements a run method which cyclically makes the reactive machine react until the whole program it contains has completed its execution. So one can call directly the method run of a machine make the system react. One can also use a machine directly has a parameter for a new Thread. So the thread will handle reaction until the end of the program in the reactive machine.

final Thread t = new Thread(SC.emptyMachine());
t.start();

machine.displayPrompt(false);

How to compile?

javac -classpath SugarCubesv4.0.0a4.jar Short_Sequence.java

How to execute?

java -classpath SugarCubesv4.0.0a4.jar:. Short_Sequence

One should get the following result:

1-: Hello World!
This program shows sequences of printed messages!

Using the Junior API

The Junior interface of SugarCubes only provides binary sequence primitive. So to compose large sequences one has to build a tree of binary sequence.

import junior.*;

public class Junior_Short_Sequence
{
    public static void main(final String[] args){
// The Junior interface of SugarCubes only provides binary sequence primitive.
        final Program print = Jr.Seq(
                                     Jr.Print("Hello World!\n")
                                     ,Jr.Seq(
                                             Jr.Print("This program shows ")
                                             ,Jr.Seq(
                                                     Jr.Print("sequences ")
                                                     ,Jr.Seq(
                                                             Jr.Print("of printed ")
                                                             ,Jr.Print("messages!\n")
                                                             )
                                                     )
                                             )
                                     );
        final Machine machine = Jr.Machine(Jr.Nothing());
        machine.add(print);
        int i = 1;
        do{
            System.out.println("instant "+(i++)+": ");
        }
        while(!machine.react());
    }
}

How to compile?

javac -classpath SugarCubesv4.0.0a4.jar Junior_Short_Sequence.java

How to execute?

java -classpath SugarCubesv4.0.0a4.jar:. Junior_Short_Sequence