prettyprinter-ansi-terminal: add 'text' flag

prettyprinter-ansi-terminal/prettyprinter-ansi-terminal.cabal

@@ -20,6 +20,15 @@ source-repository head
   type: git
   location: https://github.com/quchen/prettyprinter
 
+flag text
+  description: While it's a core value of @prettyprinter@ packages to use @Text@, there are rare
+               circumstances (mostly when @prettyprinter@ arises as a dependency of
+               test suites of packages like @bytestring@ or @text@ themselves) when
+               this is inconvenient. In this case one can disable this flag, so that
+               @prettyprinter-ansi-terminal@ fallbacks to @String@.
+  default:     True
+  manual:      True
+
 library
     exposed-modules:  Data.Text.Prettyprint.Doc.Render.Terminal
                     , Data.Text.Prettyprint.Doc.Render.Terminal.Internal
@@ -37,8 +46,17 @@ library
     build-depends:
           base          >= 4.5 && < 5
         , ansi-terminal >= 0.4.0
-        , text          >= 1.2
         , prettyprinter >= 1.7.0
+    if flag(text)
+        build-depends: text >= 1.2
+    else
+        -- A fake text package, emulating the same API, but backed by String
+        hs-source-dirs: src-text
+        other-modules:
+              Data.Text
+            , Data.Text.IO
+            , Data.Text.Lazy
+            , Data.Text.Lazy.Builder
 
     if impl(ghc >= 8.0)
         ghc-options: -Wcompat

prettyprinter-ansi-terminal/src-text/Data/Text.hs

@@ -0,0 +1,46 @@
+-- Provide a fake API, mimicking Data.Text from text package,
+-- but actually backed by type Text = String. It is used only in rare
+-- circumstances, when prettyprinter is built with -text flag.
+--
+
+{-# OPTIONS_GHC -fno-warn-missing-signatures #-}
+
+module Data.Text where
+
+import Prelude hiding (head, length, null, replicate)
+import qualified Data.Char
+import qualified Data.List
+
+type Text = String
+cons = (:)
+dropWhileEnd = Data.List.dropWhileEnd
+head = Data.List.head
+intercalate = Data.List.intercalate
+length = Data.List.length :: [Char] -> Int
+lines = Data.List.lines
+map = Data.List.map
+null = Data.List.null :: [Char] -> Bool
+pack = id
+replicate = (Data.List.concat .) . Data.List.replicate
+singleton = (:[])
+snoc xs x = xs ++ [x]
+stripEnd = dropWhileEnd Data.Char.isSpace
+unlines = Data.List.unlines
+unpack = id
+words = Data.List.words
+
+uncons :: Text -> Maybe (Char, Text)
+uncons [] = Nothing
+uncons (x : xs) = Just (x, xs)
+
+splitOn :: Text -> Text -> [Text]
+splitOn pat src
+  | null pat = error "splitOn: empty pattern"
+  | otherwise = go [] src
+  where
+    go acc [] = [reverse acc]
+    go acc xs@(y : ys)
+      | pat `Data.List.isPrefixOf` xs
+      = reverse acc : go [] (drop (length pat) xs)
+      | otherwise
+      = go (y : acc) ys

prettyprinter-ansi-terminal/src-text/Data/Text/IO.hs

@@ -0,0 +1,13 @@
+-- Provide a fake API, mimicking Data.Text.IO from text package,
+-- but actually backed by type Text = String. It is used only in rare
+-- circumstances, when prettyprinter is built with -text flag.
+--
+
+{-# OPTIONS_GHC -fno-warn-missing-signatures #-}
+
+module Data.Text.IO where
+
+import qualified System.IO
+
+hPutStr = System.IO.hPutStr
+putStrLn = System.IO.putStrLn

prettyprinter-ansi-terminal/src-text/Data/Text/Lazy.hs

@@ -0,0 +1,15 @@
+-- Provide a fake API, mimicking Data.Text.Lazy from text package,
+-- but actually backed by type Text = String. It is used only in rare
+-- circumstances, when prettyprinter is built with -text flag.
+--
+
+{-# OPTIONS_GHC -fno-warn-missing-signatures #-}
+
+module Data.Text.Lazy where
+
+import Data.Text as T
+
+type Text = T.Text
+length = T.length
+lines = T.lines
+toStrict = id

prettyprinter-ansi-terminal/src-text/Data/Text/Lazy/Builder.hs

@@ -0,0 +1,13 @@
+-- Provide a fake API, mimicking Data.Text.Lazy.Builder from text package,
+-- but actually backed by type Builder = String. It is used only in rare
+-- circumstances, when prettyprinter is built with -text flag.
+--
+
+{-# OPTIONS_GHC -fno-warn-missing-signatures #-}
+
+module Data.Text.Lazy.Builder where
+
+type Builder = String
+fromText = id
+singleton = (:[])
+toLazyText = id