Subj : Re: Looking for Spidermonkey equivalent of Mozilla/DOM trick...
To   : Anton van Straaten <anton@appsolutions.com>
From : Igor Bukanov <igor@fastmail.fm>
Date : Thu Nov 27 2003 09:01 am

Anton van Straaten wrote:
> Igor Bukanov wrote:
> 
>> Anton van Straaten wrote:
>>
>>> Since this program is already structured around setTimeout, I'm 
>>> wondering if there are any easy tricks similar to setTimeout that I 
>>> can use under Spidermonkey without DOM?  I could implement a 
>>> trampoline-style top-level loop and do this myself, I'm just looking 
>>> for a lazy way out.
>>
>>
>>
>> What about pure EcmaScript solution like:
>>
>> var functionToContinue = callTheProgram();
>> while (functionToContinue != null) {
>>   functionToContinue();
>> }
>>
>> where you program instead of calling setTimeout and returning would 
>> simply return function to continue that would be called from the top 
>> level?
> 
> 
> Thanks, that's more or less what I meant by a "trampoline-style 
> top-level loop".  It would work, but the problem in this case is that 
> the program in question is not currently set up to do this, and would 
> require some restructuring.  So I was hoping for a shortcut...

But why does it need any restructuring? In the following example the 
only restructuring that is necessary compared with version in the 
<script> tag is additional code at the bottom of the file.

Regards, Igor


function program(N)
{
	var buffer = [];
	function recursion(N)
	{
		buffer.push(N);
		if (N == 0) {
			setTimeout(use_result, 0, buffer);
			return;
		}
		setTimeout(recursion, 0, N - 1);
	}
	setTimeout(recursion, 0, N);
}

function use_result(buffer)
{
	alert(uneval(buffer));
}


program(10);

// setTimeout replacement

var timeout_data;
while (timeout_data) {
	var timeout_data_tmp = timeout_data;
	timeout_data = null;
	timeout_data_tmp.f.apply(this, timeout_data_tmp.args);
}

function setTimeout(f, time)
{
	var args;
	if (arguments.length <= 2) {
		args = [];
	} else {
   		args = Array.apply(this, arguments);
		// remove f and time
		args.shift();
		args.shift();
	}
	timeout_data = {f: f, args: args};
}

// alert replacement in shell

function alert()
{
	print.apply(this, arguments);
}

.