<div dir="ltr"><div class="gmail_extra"><div class="gmail_quote">On Thu, Dec 21, 2017 at 11:55 AM, Terry Reedy <span dir="ltr"><<a href="mailto:tjreedy@udel.edu" target="_blank">tjreedy@udel.edu</a>></span> wrote:</div><div class="gmail_quote"><br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
I think the understanding problem with this feature arises from two factors: using annotations to define possibly un-initialized slots is non-obvious; a new use of annotations for something other than static typing is a bit of a reversal of the recent pronouncement 'annotations should only be used for static typing'. </blockquote><div><br></div><div>you know, that may be where part of my confusion came from -- all the talk lately has been about "type hints" and "type annotations" -- the idea of "arbitrary annotations" has been lost.</div><div> <br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Therefore, getting the permanent doc 'right' is important.<br></blockquote><div><br></div><div>yup.</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
@dataclass<br>
class C:<br>
  x<br>
  y = 0<br>
<br>
I think the doc should explicitly say that uninitialized fields require annotation with something (anything, not necessarily a type) simply to avoid NameError during class creation. </blockquote><div><br></div><div>would this be possible?</div><div><br></div><div>@dataclass</div><div>class C:</div><div>  x:</div><div>  y: = 0</div><div><br></div><div>That is -- the colon indicates an annotation, but in this case, it's a "nothing" annotation.</div><div><br></div><div>It's a syntax error now, but would it be possible to change that? Or would the parsing be ambiguous? particularly in other contexts.</div><div><br></div><div>of course, then we'd need something to store in as a "nothing" annotation -- empty string? None? (but None might mean something) create yet anther type for "nothing_annotation"</div><div><br></div><div>Hmm, I may have talked myself out of it....</div><div><br></div><div>-CHB</div><div><br></div><div><br></div></div>-- <br><div class="m_-4350640138893935658gmail_signature" data-smartmail="gmail_signature"><br>Christopher Barker, Ph.D.<br>Oceanographer<br><br>Emergency Response Division<br>NOAA/NOS/OR&R       <a href="tel:(206)%20526-6959" value="+12065266959" target="_blank">(206) 526-6959</a>  voice<br>7600 Sand Point Way NE   <a href="tel:(206)%20526-6329" value="+12065266329" target="_blank">(206) 526-6329</a>  fax<br>Seattle, WA  98115     <a href="tel:(206)%20526-6317" value="+12065266317" target="_blank">(206) 526-6317</a>  main reception<br><br><a href="mailto:Chris.Barker@noaa.gov" target="_blank">Chris.Barker@noaa.gov</a></div>
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