Can Template Haskell find out the names and/or the declarations of the associated type synonyms declared in a type class?  I expected [`reify`](http://hackage.haskell.org/packages/archive/template-haskell/latest/doc/html/Language-Haskell-TH.html#v:reify) would do what I want, but it doesn&#39;t seem to provide all the necessary information.  It works for getting function type signatures:

    % ghci
    GHCi, version 7.8.3: http://www.haskell.org/ghc/  :? for help
    ...
    Prelude&gt; -- I&#39;ll be inserting line breaks and whitespace for clarity
    Prelude&gt; -- in all GHCi output.
    Prelude&gt; :set -XTemplateHaskell 
    Prelude&gt; import Language.Haskell.TH
    Prelude Language.Haskell.TH&gt; class C a where f :: a -&gt; Int
    Prelude Language.Haskell.TH&gt; putStrLn $(stringE . show =&lt;&lt; reify &#39;&#39;C)
    ClassI (ClassD [] Ghci1.C [PlainTV a_1627398388] []
                   [SigD Ghci1.f
                         (ForallT [PlainTV a_1627398388]
                                  [ClassP Ghci1.C [VarT a_1627398388]]
                                  (AppT (AppT ArrowT (VarT a_1627398388))
                                        (ConT GHC.Types.Int)))])
           []

However, adding an associated type synonym to the class causes no change (up to renaming) in the output:

    Prelude Language.Haskell.TH&gt; :set -XTypeFamilies 
    Prelude Language.Haskell.TH&gt; class C&#39; a where type F a :: * ; f&#39; :: a -&gt; Int
    Prelude Language.Haskell.TH&gt; putStrLn $(stringE . show =&lt;&lt; reify &#39;&#39;C&#39;)
    ClassI (ClassD [] Ghci3.C&#39; [PlainTV a_1627405973] []
                   [SigD Ghci3.f&#39;
                         (ForallT [PlainTV a_1627405973]
                                  [ClassP Ghci3.C&#39; [VarT a_1627405973]]
                                  (AppT (AppT ArrowT (VarT a_1627405973))
                                        (ConT GHC.Types.Int)))])
           []

If I know the name of `F`, I can look up information about it:

    Prelude Language.Haskell.TH&gt; putStrLn $(stringE . show =&lt;&lt; reify &#39;&#39;F)
    FamilyI (FamilyD TypeFam
                     Ghci3.F
                     [PlainTV a_1627405973]
                     (Just StarT))
            []

But I can&#39;t find the name of `F` in the first place.  Even if I add an instance of the type class, the `InstanceD` has none of the information about the definition:

    Prelude Language.Haskell.TH&gt; instance C&#39; [a] where type F [a] = a ; f&#39; = length
    Prelude Language.Haskell.TH&gt; f&#39; &quot;Haskell&quot;
    7
    Prelude Language.Haskell.TH&gt; 42 :: F [Integer]
    42
    Prelude Language.Haskell.TH&gt; putStrLn $(stringE . show =&lt;&lt; reify &#39;&#39;C&#39;)
    ClassI (ClassD [] Ghci3.C&#39; [PlainTV a_1627405973] []
                   [SigD Ghci3.f&#39;
                         (ForallT [PlainTV a_1627405973]
                                  [ClassP Ghci3.C&#39; [VarT a_1627405973]]
                                  (AppT (AppT ArrowT (VarT a_1627405973))
                                        (ConT GHC.Types.Int)))])
           [InstanceD []
                      (AppT (ConT Ghci3.C&#39;)
                            (AppT ListT (VarT a_1627406161)))
                      []]

If `reify` won&#39;t work, is there a workaround, other than listing the associate type synonyms manually?

This problem is present in GHC 7.8.3 with version 2.9.0.0 of the template-haskell package; it was also present in GHC 7.4.2 with version 2.7.0.0 of the template-haskell package.  (I didn&#39;t check on GHC 7.6.\*, but I imagine it was present there too.)  I&#39;m interested in solutions for any version of GHC (including &quot;this was only fixed in GHC version *V*&quot;).

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Getting associated type synonyms with template Haskell