416fa83 · generic-lens

src/Data/Generics/Internal/Families/Changing.hs+24

compare with master

unifiedsplit

@@ -119,3 +119,27 @@ type family ReplaceArg (t :: k) (pos :: Peano) (to :: j) :: k where

119type family ReplaceArgs (t :: k) (subs :: [Sub]) :: k where

120 ReplaceArgs t '[] = t

121 ReplaceArgs t ('Sub n arg ': ss) = ReplaceArgs (ReplaceArg t n arg) ss

122+

123+-- Note [CPP in instance constraints]

124+-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

125+--

126+-- In GHC 8.0.2, the calculated size of the expressions is too large for the

127+-- inliner to consider them under the default -funfolding-use-threshold value

128+-- (60).

129+--

130+-- To reduce the size, the constraints

131+--

132+-- ```

133+-- s' ~ Proxied s

134+-- t' ~ Proxied t

135+-- ```

136+--

137+-- are written as the following single equality:

138+--

139+-- ```

140+-- '(s', t') ~ '(Proxied s, Proxied t)

141+-- ```

142+--

143+-- However, for some reason, this violates the functional dependencies on 8.2.2.

144+-- Therefore, when using a newer version of the compiler, the original constraints

145+-- are used, as the expression size is smaller under 8.2.2.

src/Data/Generics/Product/Fields.hs+7−1

@@ -1,4 +1,5 @@

1{-# LANGUAGE AllowAmbiguousTypes #-}

2+{-# LANGUAGE CPP #-}

2{-# LANGUAGE ConstraintKinds #-}

3{-# LANGUAGE ConstraintKinds #-}

3{-# LANGUAGE DataKinds #-}

4{-# LANGUAGE DataKinds #-}

4{-# LANGUAGE FlexibleInstances #-}

5{-# LANGUAGE FlexibleInstances #-}

@@ -127,15 +128,20 @@ instance -- see Note [Changing type parameters]

127 ( Generic s

128 ( Generic s

128 , ErrorUnless field s (CollectField field (Rep s))

129 , ErrorUnless field s (CollectField field (Rep s))

129 , Generic t

130 , Generic t

131+ -- see Note [CPP in instance constraints]

132+#if __GLASGOW_HASKELL__ < 802

133+ , '(s', t') ~ '(Proxied s, Proxied t)

134+#else

130 , s' ~ Proxied s

135 , s' ~ Proxied s

131 , t' ~ Proxied t

136 , t' ~ Proxied t

137+#endif

132 , Generic s'

138 , Generic s'

133 , Generic t'

139 , Generic t'

134 , GHasField' field (Rep s) a

140 , GHasField' field (Rep s) a

135 , GHasField' field (Rep s') a'

141 , GHasField' field (Rep s') a'

142+ , GHasField' field (Rep t') b'

136 , GHasField field (Rep s) (Rep t) a b

143 , GHasField field (Rep s) (Rep t) a b

137 , t ~ Infer s a' b

144 , t ~ Infer s a' b

138− , GHasField' field (Rep t') b'

139 , s ~ Infer t b' a

145 , s ~ Infer t b' a

140 ) => HasField field s t a b where

146 ) => HasField field s t a b where

141

147

src/Data/Generics/Product/Positions.hs+6

@@ -1,3 +1,4 @@

1+{-# LANGUAGE CPP #-}

1{-# LANGUAGE AllowAmbiguousTypes #-}

2{-# LANGUAGE AllowAmbiguousTypes #-}

2{-# LANGUAGE ConstraintKinds #-}

3{-# LANGUAGE ConstraintKinds #-}

3{-# LANGUAGE DataKinds #-}

4{-# LANGUAGE DataKinds #-}

@@ -99,8 +100,13 @@ instance -- see Note [Changing type parameters]

99 ( Generic s

100 ( Generic s

100 , ErrorUnless i s (0 <? i && i <=? Size (Rep s))

101 , ErrorUnless i s (0 <? i && i <=? Size (Rep s))

101 , Generic t

102 , Generic t

103+ -- see Note [CPP in instance constraints]

104+#if __GLASGOW_HASKELL__ < 802

105+ , '(s', t') ~ '(Proxied s, Proxied t)

106+#else

102 , s' ~ Proxied s

107 , s' ~ Proxied s

103 , t' ~ Proxied t

108 , t' ~ Proxied t

109+#endif

104 , Generic s'

110 , Generic s'

105 , Generic t'

111 , Generic t'

106 , GHasPosition' i (Rep s) a

112 , GHasPosition' i (Rep s) a

src/Data/Generics/Sum/Constructors.hs+7−1

@@ -1,4 +1,5 @@

1{-# LANGUAGE AllowAmbiguousTypes #-}

2+{-# LANGUAGE CPP #-}

2{-# LANGUAGE DataKinds #-}

3{-# LANGUAGE DataKinds #-}

3{-# LANGUAGE FlexibleInstances #-}

4{-# LANGUAGE FlexibleInstances #-}

4{-# LANGUAGE FunctionalDependencies #-}

5{-# LANGUAGE FunctionalDependencies #-}

@@ -102,8 +103,13 @@ instance

102 ( Generic s

103 ( Generic s

103 , ErrorUnless ctor s (HasCtorP ctor (Rep s))

104 , ErrorUnless ctor s (HasCtorP ctor (Rep s))

104 , Generic t

105 , Generic t

106+ -- see Note [CPP in instance constraints]

107+#if __GLASGOW_HASKELL__ < 802

108+ , '(s', t') ~ '(Proxied s, Proxied t)

109+#else

105 , s' ~ Proxied s

110 , s' ~ Proxied s

106− , t' ~ Proxied s

111+ , t' ~ Proxied t

112+#endif

107 , Generic s'

113 , Generic s'

108 , Generic t'

114 , Generic t'

109 , GAsConstructor' ctor (Rep s) a

115 , GAsConstructor' ctor (Rep s) a