How do I create a fileWatcher with an onFileChange event using spawn?

[Enjoys Math via Digitalmars-d-learn]

Something like this:


module file_watcher;

import std.concurrency;
import std.file;
import std.signals;
import std.datetime;


void fileWatcher(Tid tid, string filename, int loopSleep) {
	auto modified0 = timeLastModified(filename);

	while (true) {
		modified = timeLastModified(filename);
			
		if (modified > modified0) {
			modified0 = modified;
			//if (onFileChange !is null)
			//    onFileChange(receiver);
		}

		sleep(dur!"msecs"(loopSleep));
	}
}


But I'm not sure how to send the onFiledChange event.