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<p class="MsoNormal"><span style="font-size:12.0pt">Ryan<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt">If you compile <o:p></o:p></span></p>
<p class="Code">newtype Compose f g a = Compose (f (g a)) deriving( Generic1 )<o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:12.0pt">and do –show-iface on the resulting hi file, you’ll see<o:p></o:p></span></p>
<p class="Code"> $fGeneric1Compose ::<o:p></o:p></p>
<p class="Code"> forall (f :: * -> *) k (g :: k -> *).<o:p></o:p></p>
<p class="Code"> Functor f =><o:p></o:p></p>
<p class="Code"> Generic1 (Compose f g)<o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:12.0pt">I was expecting to see <o:p></o:p></span></p>
<p class="Code"> $fGeneric1Compose ::<o:p></o:p></p>
<p class="Code"> forall (f :: <span style="color:red">k1</span> -> *) k (g :: k ->
<span style="color:red">k1</span>).<o:p></o:p></p>
<p class="Code"> (..something..) =><o:p></o:p></p>
<p class="Code"> Generic1 (Compose f g)<o:p></o:p></p>
<p class="MsoNormal"><b><span style="font-size:12.0pt">Otherwise the Generic1 instance only works if its first argument has kind (* -> *).<o:p></o:p></span></b></p>
<p class="MsoNormal"><span style="font-size:12.0pt">Is that the intention? Maybe so…<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt">Simon<o:p></o:p></span></p>
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