// noprotect

​

function multBy20(v) {

  // fake-delayed math

  return ASQ.after(500,v*20);

}

​

function addTo2(v) {

  // fake-delayed math

  return ASQ.after(500,v+2);

}

​

​

function *foo(token) {

    // grab message off the top of the channel

    var value = token.messages.pop(); // 2

​

    // put another message onto the channel

    // `multBy20(..)` is a promise-generating function

    // that multiplies a value by `20` after some delay

    token.messages.push( yield multBy20( value ) );

​

    // transfer control

    yield token;

​

    // a final message from the CSP run

    yield ("meaning of life: " + token.messages[0]);

}

​

function *bar(token) {

    // grab message off the top of the channel

    var value = token.messages.pop(); // 40

​

    // put another message onto the channel

    // `addTo2(..)` is a promise-generating function

    // that adds value to `2` after some delay

    token.messages.push( yield addTo2( value ) );

​

    // transfer control

    yield token;

}

​

// start out a sequence with the initial message value of `2`

ASQ( 2 )

​

// run the two CSP processes paired together

.runner(

    foo,

    bar

)

​

// whatever message we get out, pass it onto the next

// step in our sequence

.val( function(msg){

    console.log( msg ); // "meaning of life: 42"

} );