Declare optional parameters according to HTML standard

[lbolla]

According to
https://html.spec.whatwg.org/multipage/webappapis.html#timers timeout
and handles of setTimeout and friends are optional.

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[sophiebits]

I don't think these arguments to the clear functions should be optional?

[lbolla]

From the HTML standard, it looks like the parameters of clearInterval and clearTimeout are indeed optional: https://html.spec.whatwg.org/#dom-windowtimers-cleartimeout
I hope I am not misinterpreting the standard, though.

[sophiebits]

I see, the IDL does indeed mark them optional (though I'm unsure when that would be useful). I got confused by this section which makes them look required:

Still feels weird to me though – if you're just calling clearTimeout() or clearInterval() with no arguments, that sounds like a bug to me.

[fkling]

It's true, the parameter is defined as optional:

interface WindowTimers {
  long setTimeout(Function handler, optional long timeout = 0, any... arguments);
  long setTimeout(DOMString handler, optional long timeout = 0, any... arguments);
  void clearTimeout(optional long handle = 0);
  long setInterval(Function handler, optional long timeout = 0, any... arguments);
  long setInterval(DOMString handler, optional long timeout = 0, any... arguments);
  void clearInterval(optional long handle = 0);
};

in which case 0 is assigned to handle.

However, I'd argue that 99% of the cases where no handle is passed, are errors.

[Daniel15]

Wow, that's really strange. What's the expected behaviour if you call clearInterval or clearTimeout with no handle? How could that possibly ever be useful?

[fkling]

@Daniel15 : The spec says that the function does nothing if the handle is not found in the handle list (I guess the handle 0 (the default value) is never in the list).

[Daniel15]

@fkling Well, that's silly. I don't see any actual use for having a default value for handle. I'd love to meet whoever added that to the spec and ask them what they were thinking :)

[help999me]

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