@jbalsas That seems reasonable.  Of course, other things like `isNaN("   ") = false` too, so one option is to check for `.trim() !== ""` in addition to isNaN -- which then opens the door to simplifying the regexp.  But that case doesn't bother me a lot -- treating ":42, " as ":42,0" doesn't seem too terrible to me -- if you typed a space you're probably about to type a digit next anyway.  So I'm ok with leaving it as-is unless that edge case bothers you.