dojox
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Dojo eXtensions, a rollup of many useful sub-projects and varying states of maturity – from very stable and robust, to alpha and experimental. See individual projects contain README files for details.
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HTML
<html>
<head>
<title>Clocking recursion combinators</title>
<style type="text/css">
@import "../../../dojo/resources/dojo.css";
</style>
<script type="text/javascript" src="../../../dojo/dojo.js" data-dojo-config="isDebug:true"></script>
<script type="text/javascript" src="../functional.js"></script>
<script type="text/javascript" src="../functional/linrec.js"></script>
<script type="text/javascript" src="../functional/tailrec.js"></script>
<script type="text/javascript" src="../functional/numrec.js"></script>
<script type="text/javascript" src="../functional/binrec.js"></script>
<script type="text/javascript" src="../functional/multirec.js"></script>
<script type="text/javascript" src="../functional/sequence.js"></script>
<script type="text/javascript">
// reference implementations
var linrec1 = function(cond, then, before, after){
var cond = df.lambda(cond),
then = df.lambda(then),
before = df.lambda(before),
after = df.lambda(after);
return function(){
if(cond.apply(this, arguments)){
return then.apply(this, arguments);
}
var args = before.apply(this, arguments);
var ret = arguments.callee.apply(this, args);
return after.call(this, ret, arguments);
};
};
var linrec2 = function(cond, then, before, after){
var cond = df.lambda(cond),
then = df.lambda(then),
before = df.lambda(before),
after = df.lambda(after);
return function(){
var args = arguments, top, ret;
// 1st part
for(; !cond.apply(this, args); args = before.apply(this, args)){
top = {prev: top, args: args};
}
ret = then.apply(this, args);
//2nd part
for(; top; top = top.prev){
ret = after.call(this, ret, top.args);
}
return ret;
};
};
var tailrec1 = function(cond, then, before){
var cond = df.lambda(cond),
then = df.lambda(then),
before = df.lambda(before);
return function(){
if(cond.apply(this, arguments)){
return then.apply(this, arguments);
}
var args = before.apply(this, arguments);
return arguments.callee.apply(this, args);
};
};
var tailrec2 = function(cond, then, before){
var cond = df.lambda(cond),
then = df.lambda(then),
before = df.lambda(before);
return function(){
var args = arguments;
for(; !cond.apply(this, args); args = before.apply(this, args));
return then.apply(this, args);
};
};
var numrec1 = function(then, after){
var after = df.lambda(after);
return function(x){
return x ? after.call(this, arguments.callee.call(this, x - 1), x) : then;
};
};
var numrec2 = function(then, after){
var after = df.lambda(after);
return function(x){
var ret = then, i;
for(i = 1; i <= x; ++i){
ret = after.call(this, ret, i);
}
return ret;
};
};
var binrec1 = function(cond, then, before, after){
var cond = df.lambda(cond),
then = df.lambda(then),
before = df.lambda(before),
after = df.lambda(after);
return function(){
if(cond.apply(this, arguments)){
return then.apply(this, arguments);
}
var args = before.apply(this, arguments);
var ret1 = arguments.callee.apply(this, args[0]);
var ret2 = arguments.callee.apply(this, args[1]);
return after.call(this, ret1, ret2, arguments);
};
};
var binrec2 = function(cond, then, before, after){
var cond = df.lambda(cond),
then = df.lambda(then),
before = df.lambda(before),
after = df.lambda(after);
return function(){
var top1, top2, ret, args = arguments;
// first part: start the pump
while(!cond.apply(this, args)){
ret = before.apply(this, args);
top1 = {prev: top1, args: ret[1]};
top2 = {prev: top2, args: args};
args = ret[0];
}
for(;;){
// second part: mop up
do{
ret = then.apply(this, args);
if(!top2){
return ret;
}
while("ret" in top2){
ret = after.call(this, top2.ret, ret, top2.args);
if(!(top2 = top2.prev)){
return ret;
}
}
top2.ret = ret;
args = top1.args;
top1 = top1.prev;
}while(cond.apply(this, args));
// first part (encore)
do{
ret = before.apply(this, args);
top1 = {prev: top1, args: ret[1]};
top2 = {prev: top2, args: args};
args = ret[0];
}while(!cond.apply(this, args));
}
};
};
var multirec1 = function(cond, then, before, after){
var cond = df.lambda(cond),
then = df.lambda(then),
before = df.lambda(before),
after = df.lambda(after);
return function(){
if(cond.apply(this, arguments)){
return then.apply(this, arguments);
}
var args = before.apply(this, arguments),
ret = new Array(args.length);
for(var i = 0; i < args.length; ++i){
ret[i] = arguments.callee.apply(this, args[i]);
}
return after.call(this, ret, arguments);
};
};
var multirec2 = function(cond, then, before, after){
var cond = df.lambda(cond),
then = df.lambda(then),
before = df.lambda(before),
after = df.lambda(after);
return function(){
var top = {args: arguments}, args, ret, parent, i;
for(;;){
for(;;){
if(top.old){
ret = after.call(this, top.ret, top.old);
break;
}
args = top.args;
if(cond.apply(this, args)){
ret = then.apply(this, args);
break;
}
top.old = args;
args = before.apply(this, args);
top.ret = [];
parent = top;
for(i = args.length - 1; i >= 0; --i){
top = {prev: top, args: args[i], parent: parent};
}
}
if(!(parent = top.parent)){
return ret;
}
parent.ret.push(ret);
top = top.prev;
}
};
};
// tests
var clock = function(body){
var b = new Date();
body();
var e = new Date();
return e.getTime() - b.getTime(); // in ms
};
var log = function(name, body){
var ms = clock(body);
console.log(name + ":", ms);
};
var LEN1 = 15, LEN2 = 10, ITER = 1000, tests = {},
df = dojox.lang.functional,
sample1 = df.repeat(LEN1, "+1", 0),
sample2 = df.repeat(LEN2, "+1", 0);
var fact1 = function(n){
var ret = 1;
for(var i = 2; i <= n; ++i){
ret *= i;
}
return ret;
};
tests["factorial: raw iterative"] = function(){
for(var i = 0; i < ITER; ++i){
df.forEach(sample1, fact1);
}
};
var fact2 = function(n){ return n ? n * arguments.callee.call(this, n - 1) : 1; };
tests["factorial: raw recursion"] = function(){
for(var i = 0; i < ITER; ++i){
df.forEach(sample1, fact2);
}
};
var fact3_1 = linrec1("<= 1", "1", "[n - 1]", "a * b[0]");
tests["factorial: linrec1 (recursive reference)"] = function(){
for(var i = 0; i < ITER; ++i){
df.forEach(sample1, fact3_1);
}
};
var fact3_2 = linrec2("<= 1", "1", "[n - 1]", "a * b[0]");
tests["factorial: linrec2 (iterative reference)"] = function(){
for(var i = 0; i < ITER; ++i){
df.forEach(sample1, fact3_2);
}
};
var fact3 = df.linrec("<= 1", "1", "[n - 1]", "a * b[0]");
tests["factorial: linrec"] = function(){
for(var i = 0; i < ITER; ++i){
df.forEach(sample1, fact3);
}
};
var fact4_1 = numrec1(1, "*");
tests["factorial: numrec1 (recursive reference)"] = function(){
for(var i = 0; i < ITER; ++i){
df.forEach(sample1, fact4_1);
}
};
var fact4_2 = numrec2(1, "*");
tests["factorial: numrec2 (iterative reference)"] = function(){
for(var i = 0; i < ITER; ++i){
df.forEach(sample1, fact4_2);
}
};
var fact4 = df.numrec(1, "*");
tests["factorial: numrec"] = function(){
for(var i = 0; i < ITER; ++i){
df.forEach(sample1, fact4);
}
};
var fact5_1a = tailrec1("<= 1", "a, b -> b", "[n - 1, n * acc]");
var fact5_1 = function(n){ return fact5_1a(n, 1); };
tests["factorial: tailrec1 (recursive reference)"] = function(){
for(var i = 0; i < ITER; ++i){
df.forEach(sample1, fact5_1);
}
};
var fact5_2a = tailrec2("<= 1", "a, b -> b", "[n - 1, n * acc]");
var fact5_2 = function(n){ return fact5_2a(n, 1); };
tests["factorial: tailrec2 (iterative reference)"] = function(){
for(var i = 0; i < ITER; ++i){
df.forEach(sample1, fact5_2);
}
};
var fact5a = df.tailrec("<= 1", "a, b -> b", "[n - 1, n * acc]");
var fact5 = function(n){ return fact5a(n, 1); };
tests["factorial: tailrec"] = function(){
for(var i = 0; i < ITER; ++i){
df.forEach(sample1, fact5);
}
};
var fact6_1 = multirec1("<= 0", "1", "[[n - 1]]", "a[0] * b[0]");
tests["factorial: multirec1 (recursive reference)"] = function(){
for(var i = 0; i < ITER; ++i){
df.forEach(sample1, fact6_1);
}
};
var fact6_2 = multirec2("<= 0", "1", "[[n - 1]]", "a[0] * b[0]");
tests["factorial: multirec2 (iterative reference)"] = function(){
for(var i = 0; i < ITER; ++i){
df.forEach(sample1, fact6_2);
}
};
var fact6 = df.multirec("<= 0", "1", "[[n - 1]]", "a[0] * b[0]");
tests["factorial: multirec"] = function(){
for(var i = 0; i < ITER; ++i){
df.forEach(sample1, fact6);
}
};
var fib1 = function(n){
var a = 1, b = 1;
for(var i = 2; i <= n; ++i){
var c = a + b;
b = a;
a = c;
}
return a;
};
tests["fibonacci: raw iterative"] = function(){
for(var i = 0; i < ITER; ++i){
df.forEach(sample2, fib1);
}
};
var fib2 = function(n){ return n <= 1 ? 1 : arguments.callee.call(this, n - 1) + arguments.callee.call(this, n - 2); };
tests["fibonacci: raw recursion"] = function(){
for(var i = 0; i < ITER; ++i){
df.forEach(sample2, fib2);
}
};
var fib3a = function(n, next, result){ return n <= 0 ? result : arguments.callee.call(this, n - 1, next + result, next); };
var fib3 = function(n){ return fib3a(n, 1, 1); };
tests["fibonacci: raw tail recursion"] = function(){
for(var i = 0; i < ITER; ++i){
df.forEach(sample2, fib3);
}
};
var fib4_1 = binrec1("<= 1", "1", "[[n - 1], [n - 2]]", "+");
tests["fibonacci: binrec1 (recursive reference)"] = function(){
for(var i = 0; i < ITER; ++i){
df.forEach(sample2, fib4_1);
}
};
var fib4_2 = binrec2("<= 1", "1", "[[n - 1], [n - 2]]", "+");
tests["fibonacci: binrec2 (iterative reference)"] = function(){
for(var i = 0; i < ITER; ++i){
df.forEach(sample2, fib4_2);
}
};
var fib4 = df.binrec("<= 1", "1", "[[n - 1], [n - 2]]", "+");
tests["fibonacci: binrec"] = function(){
for(var i = 0; i < ITER; ++i){
df.forEach(sample2, fib4);
}
};
var fib5_1a = tailrec1("<= 0", "a, b, c -> c", "[n - 1, next + result, next]");
var fib5_1 = function(n){ return fib5_1a(n, 1, 1); };
tests["fibonacci: tailrec1 (recursive reference)"] = function(){
for(var i = 0; i < ITER; ++i){
df.forEach(sample2, fib5_1);
}
};
var fib5_2a = tailrec2("<= 0", "a, b, c -> c", "[n - 1, next + result, next]");
var fib5_2 = function(n){ return fib5_2a(n, 1, 1); };
tests["fibonacci: tailrec2 (iterative reference)"] = function(){
for(var i = 0; i < ITER; ++i){
df.forEach(sample2, fib5_2);
}
};
var fib5a = df.tailrec("<= 0", "a, b, c -> c", "[n - 1, next + result, next]");
var fib5 = function(n){ return fib5a(n, 1, 1); };
tests["fibonacci: tailrec"] = function(){
for(var i = 0; i < ITER; ++i){
df.forEach(sample2, fib5);
}
};
var fib6_1 = multirec1("<= 1", "1", "[[n - 1], [n - 2]]", "a[0] + a[1]");
tests["fibonacci: multirec1 (recursive reference)"] = function(){
for(var i = 0; i < ITER; ++i){
df.forEach(sample2, fib6_1);
}
};
var fib6_2 = multirec2("<= 1", "1", "[[n - 1], [n - 2]]", "a[0] + a[1]");
tests["fibonacci: multirec2 (iterative reference)"] = function(){
for(var i = 0; i < ITER; ++i){
df.forEach(sample2, fib6_2);
}
};
var fib6 = df.multirec("<= 1", "1", "[[n - 1], [n - 2]]", "a[0] + a[1]");
tests["fibonacci: multirec"] = function(){
for(var i = 0; i < ITER; ++i){
df.forEach(sample2, fib6);
}
};
var keys = df.keys(tests), i = 0;
var doTest = function(){
log(keys[i], tests[keys[i]]);
++i;
if(i < keys.length){
setTimeout(doTest, 20);
}else{
console.log("that's all");
}
};
var test = function(){
i = 0;
setTimeout(doTest, 20);
};
dojo.addOnLoad(function(){
// sanity check
console.assert(fact1(5) == 120, "fact1");
console.assert(fact2(5) == 120, "fact2");
console.assert(fact3_1(5) == 120, "fact3_1");
console.assert(fact3_2(5) == 120, "fact3_2");
console.assert(fact3(5) == 120, "fact3");
console.assert(fact4_1(5) == 120, "fact4_1");
console.assert(fact4_2(5) == 120, "fact4_2");
console.assert(fact4(5) == 120, "fact4");
console.assert(fact5_1(5) == 120, "fact5_1");
console.assert(fact5_2(5) == 120, "fact5_2");
console.assert(fact5(5) == 120, "fact5");
console.assert(fact6_1(5) == 120, "fact6_1");
console.assert(fact6_2(5) == 120, "fact6_2");
console.assert(fact6(5) == 120, "fact6");
console.assert(fib1(5) == 8, "fib1");
console.assert(fib2(5) == 8, "fib2");
console.assert(fib3(5) == 8, "fib3");
console.assert(fib4_1(5) == 8, "fib4_1");
console.assert(fib4_2(5) == 8, "fib4_2");
console.assert(fib4(5) == 8, "fib4");
console.assert(fib5_1(5) == 8, "fib5_1");
console.assert(fib5_2(5) == 8, "fib5_2");
console.assert(fib5(5) == 8, "fib5");
console.assert(fib6_1(5) == 8, "fib6_1");
console.assert(fib6_2(5) == 8, "fib6_2");
console.assert(fib6(5) == 8, "fib6");
console.log("sanity check finished");
});
</script>
</head>
<body>
<p>This test is meant to run with Firebug. Open the console to see the output.</p>
<p><button onclick="test()">Start</button></p>
</body>
</html>