id,summary,reporter,owner,description,type,status,priority,milestone,component,version,resolution,keywords,cc,os,architecture,failure,difficulty,testcase,blockedby,blocking,related
7066,isInstance does not work for compound types,edsko,simonpj,"Consider

{{{
import Language.Haskell.TH.Syntax                                                
                                                                                 
data A = A                                                                       
                                                                                 
test :: Q [Dec]                                                                  
test = do                                                                        
  tp <- [t| (Int, A) |]                                                          
  inst1 <- isInstance ''Show [ tp ]                                              
  runIO $ print inst1                                                            
  return []  
}}}
                                                                    
This prints True even though there is no Show instance for A (the Show instance it finds is for pairs, but it does not verify that there are Show instances for the pair components).",bug,new,normal,7.8.1,Template Haskell,7.4.2,,,,Unknown/Multiple,Unknown/Multiple,None/Unknown,Unknown,,,,