Functional Reactive Programming

Stream_of_all_Points_in_3D.js

// // // // // // // // // // // // // // // //
// set up:
// you have a counter with id="theCounts_triples"
// and buttons for the prev points, next points
// and a reset button. We order the points by
// the sum of their coordinates (i.e. along the
// diagonally cutting plane
// // // // // // // // // // // // // // // //

var tripleNext = $('#triplesNext').asEventStream('click');
var triplePrev = $('#triplesPrev').asEventStream('click');
var reset = $('#resetTriples').asEventStream('click');

function aux2(n, i, j) {
    if (i+j < n) {
	return "( " + [i, j, n-(i+j)] + " )" + ", " + aux2(n, i+1, j)
    } else {
	if (j <= n) {
	    return "( " + [i, j, n-(i+j)] + " )" + ", " + aux2(n, 0, j+1)
	} else {
	    return []
	}
    }
}

function triang(n) {
    return aux2(n, 0, 0)
}

var merg = tripleNext.map(1).merge(triplePrev.map(-1)).merge(reset.map(0));

var next = merg.scan(0, function(x,y) {if (y === 0) {return 0} else {return x + y}});

var theCounts_triples = next.map(function(x) {return "( " + triang(x).toString().slice(0, -2) + " )"});

theCounts_triples.assign($('#theCounts_triples'), 'text');