Unicode escape (#354)

* [#334] parse and unparse tests

* removed parsing and unparing tests

* [#334] showUnicodeText

* [#334] escaping unicode character as well as regular characters

* [#334] resolved issue with escaping regular unescaped chars

* added tests, but they are not in use

* examples.hs revert to original content

* [#334] changes requested by chshersh

src/Toml/Type/Printer.hs

@@ -20,15 +20,18 @@ module Toml.Type.Printer
        ) where
 
 import Data.Bifunctor (first)
+import Data.Char (isAscii, ord)
 import Data.Coerce (coerce)
 import Data.Function (on)
 import Data.HashMap.Strict (HashMap)
-import Data.List (sortBy)
+import Data.List (sortBy, foldl')
 import Data.List.NonEmpty (NonEmpty)
 import Data.Semigroup (stimes)
 import Data.Text (Text)
 import Data.Time (ZonedTime, defaultTimeLocale, formatTime)
 
+import Text.Printf (printf)
+
 import Toml.Type.AnyValue (AnyValue (..))
 import Toml.Type.Key (Key (..), Piece (..))
 import Toml.Type.PrefixTree (PrefixMap, PrefixTree (..))
@@ -40,6 +43,7 @@ import qualified Data.List.NonEmpty as NonEmpty
 import qualified Data.Text as Text
 
 
+
 {- | Configures the pretty printer.
 
 @since 0.5.0
@@ -161,7 +165,7 @@ prettyKeyValue options i = mapOrdered (\kv -> [kvText kv]) options . HashMap.toL
     valText (Bool b)    = Text.toLower $ showText b
     valText (Integer n) = showText n
     valText (Double d)  = showDouble d
-    valText (Text s)    = showText s
+    valText (Text s)    = showTextUnicode s
     valText (Zoned z)   = showZonedTime z
     valText (Local l)   = showText l
     valText (Day d)     = showText d
@@ -171,6 +175,23 @@ prettyKeyValue options i = mapOrdered (\kv -> [kvText kv]) options . HashMap.toL
     showText :: Show a => a -> Text
     showText = Text.pack . show
 
+
+    -- | Function encodes all non-ascii characters in TOML defined form using the isAscii function
+    showTextUnicode :: Text -> Text
+    showTextUnicode text = Text.pack $ show finalText
+      where
+        xss = Text.unpack text
+        finalText = foldl' (\acc (ch, asciiCh) -> acc ++ getCh ch asciiCh) "" asciiArr
+
+        asciiArr = zip xss $ asciiStatus xss
+
+        getCh :: Char -> Bool -> String
+        getCh ch True  = [ch] -- it is true ascii character
+        getCh ch False = printf "\\U%08x" (ord ch) :: String -- it is not true ascii character, it must be encoded
+
+        asciiStatus :: String -> [Bool]
+        asciiStatus = map isAscii
+
     showDouble :: Double -> Text
     showDouble d | isInfinite d && d < 0 = "-inf"
                  | isInfinite d = "inf"

test/Test/Toml/Gen.hs

@@ -299,6 +299,13 @@ genUniHex8Color = do
     hex <- genDiffHex 8
     pure . Text.pack $ "\\U" ++ hex
 
+-- | Generates some unescaped unicode string
+genUnicodeChar :: Gen Text
+genUnicodeChar = Gen.element
+    [ "č", "ć", "š", "đ", "ž", "Ö", "ё"
+    , "в", "ь", "ж", "ю", "ч", "ü", "я"
+    ]
+
 -- | Generates text from different symbols.
 genText :: Gen Text
 genText = genNotEscape $ fmap Text.concat $ Gen.list (Range.constant 0 256) $ Gen.choice
@@ -307,8 +314,10 @@ genText = genNotEscape $ fmap Text.concat $ Gen.list (Range.constant 0 256) $ Ge
     , genPunctuation
     , genUniHex4Color
     , genUniHex8Color
+    --, genUnicodeChar
     ]
 
+
 genString :: Gen String
 genString = Text.unpack <$> genText