Add Lift instances for Text.

These use the existing `Data` instances, and have similar trade-offs.

Author: quasicomputational

Data/Text.hs

@@ -244,6 +244,8 @@ import GHC.Base (eqInt, neInt, gtInt, geInt, ltInt, leInt)
 #if __GLASGOW_HASKELL__ >= 708
 import qualified GHC.Exts as Exts
 #endif
+import Language.Haskell.TH.Quote (dataToExpQ)
+import Language.Haskell.TH.Syntax (Lift, lift)
 #if MIN_VERSION_base(4,7,0)
 import Text.Printf (PrintfArg, formatArg, formatString)
 #endif
@@ -413,6 +415,16 @@ instance Data Text where
     _ -> P.error "gunfold"
   dataTypeOf _ = textDataType
 
+-- | This instance has similar considerations to the 'Data' instance:
+-- it preserves abstraction at the cost of inefficiency.
+--
+-- @since 1.2.4.0
+instance Lift Text where
+  -- Note: since we have to work on GHC 7.0, we've got to define this
+  -- explicitly, rather than relying on the nice modern 'liftData'
+  -- default.
+  lift = dataToExpQ (\ _ ->  Nothing)
+
 #if MIN_VERSION_base(4,7,0)
 -- | Only defined for @base-4.7.0.0@ and later
 --

Data/Text/Lazy.hs

@@ -239,6 +239,8 @@ import qualified GHC.Base as GHC
 import qualified GHC.Exts as Exts
 #endif
 import GHC.Prim (Addr#)
+import Language.Haskell.TH.Quote (dataToExpQ)
+import Language.Haskell.TH.Syntax (Lift, lift)
 #if MIN_VERSION_base(4,7,0)
 import Text.Printf (PrintfArg, formatArg, formatString)
 #endif
@@ -399,6 +401,16 @@ instance Data Text where
     _ -> error "Data.Text.Lazy.Text.gunfold"
   dataTypeOf _   = textDataType
 
+-- | This instance has similar considerations to the 'Data' instance:
+-- it preserves abstraction at the cost of inefficiency.
+--
+-- @since 1.2.4.0
+instance Lift Text where
+  -- Note: since we have to work on GHC 7.0, we've got to define this
+  -- explicitly, rather than relying on the nice modern 'liftData'
+  -- default.
+  lift = dataToExpQ (\ _ -> Nothing)
+
 #if MIN_VERSION_base(4,7,0)
 -- | Only defined for @base-4.7.0.0@ and later
 --

benchmarks/text-benchmarks.cabal

@@ -42,6 +42,7 @@ executable text-benchmarks
                   ghc-prim,
                   integer-gmp,
                   stringsearch,
+                  template-haskell,
                   transformers,
                   utf8-string,
                   vector

changelog.md

@@ -1,4 +1,4 @@
-### 1.2.3.1
+### 1.2.4.0
 
 * Make `decodeUtf8With` fail explicitly for unsupported non-BMP
   replacement characters instead silent undefined behaviour (gh-213)
@@ -12,6 +12,8 @@
 * A bug in the case-mapping functions resulting in unreasonably large
   allocations with large arguments has been fixed (gh-221)
 
+* `Lift` instances `Data.Text.Text` and `Data.Text.Lazy.Text`.
+
 ### 1.2.3.0
 
 * Spec compliance: `toCaseFold` now follows the Unicode 9.0 spec

tests/text-tests.cabal

@@ -147,7 +147,8 @@ library
     binary,
     deepseq,
     ghc-prim,
-    integer-gmp
+    integer-gmp,
+    template-haskell
 
   if flag(bytestring-builder)
     build-depends: bytestring         >= 0.9    && < 0.10.4,

text.cabal

@@ -1,6 +1,6 @@
 cabal-version:  >= 1.8
 name:           text
-version:        1.2.3.1
+version:        1.2.4.0
 
 homepage:       https://github.com/haskell/text
 bug-reports:    https://github.com/haskell/text/issues
@@ -147,7 +147,8 @@ library
     base       >= 4.2 && < 5,
     binary,
     deepseq    >= 1.1.0.0,
-    ghc-prim   >= 0.2
+    ghc-prim   >= 0.2,
+    template-haskell
 
   if flag(bytestring-builder)
     build-depends: bytestring         >= 0.9    && < 0.10.4,
@@ -255,6 +256,7 @@ test-suite tests
     ghc-prim,
     quickcheck-unicode >= 1.0.1.0,
     random,
+    template-haskell,
     test-framework >= 0.4,
     test-framework-hunit >= 0.2,
     test-framework-quickcheck2 >= 0.2