Annotate selectors with "!" to mean "must match"

[skrul]

A suggestion from a new jQuery user: Several times I've run into problems where my selector expression was not matching due to a bug, but it was not obvious since it is perfectly valid to traverse and manipulate an empty jQuery object.

So I propose adding a syntax to the selector expression that means "if this does not match, throw an exception." I think the "!" symbol is appropriate since it reminds me of CSS's "!important".

For example, $("#myid!") would throw an exception if #myid was not found.

Thoughts?

[dmethvin]

You could also accomplish this with a plugin:

jQuery.fn.orDie = function(msg){
  if ( !this.length)
    alert("Nothing selected! "+(msg||""));
  return this;
};

[dantman]

I don't like the idea of using !, a ! reminds me far to much of not. $('#foo!.foo');

[Rick Waldron]

! is reserved for representing "not"