Hi,<br><br><div class="gmail_quote">On Thu, Jun 7, 2012 at 2:46 AM, AntC <span dir="ltr"><<a href="mailto:anthony_clayden@clear.net.nz" target="_blank">anthony_clayden@clear.net.nz</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<br>What does the `ArgKind' message mean?<br></blockquote><div><br>`ArgKind` and `OpenKind` is what previously was called `?` and `??` (or the other<br>way around; I can't remember).<br><a href="http://hackage.haskell.org/trac/ghc/wiki/Commentary/Compiler/TypeType#Kindsubtyping">http://hackage.haskell.org/trac/ghc/wiki/Commentary/Compiler/TypeType#Kindsubtyping</a><br>
<br>You might also want to have a look at Richard and Stephanie's latest paper draft, about<br>singletons, which is related to what you are trying in your example:<br><a href="http://www.cis.upenn.edu/~eir/papers/2012/singletons/paper.pdf">http://www.cis.upenn.edu/~eir/papers/2012/singletons/paper.pdf</a><br>
</div></div><br><br>Cheers,<br>Pedro<br><br>