Add /codepoints

src/UToy/Parsers.hs

@@ -1,8 +1,9 @@
 module UToy.Parsers
   ( parseHexBytes
+  , parseCodepoints
   ) where
 
-import Data.Char (isHexDigit, ord)
+import Data.Char (isDigit, isHexDigit, ord)
 import Data.Text (Text)
 import Data.Word (Word8)
 import Text.Printf (printf)
@@ -23,9 +24,27 @@ hexBytes = hexByte `Atto.sepBy` separators
     hexDigit = hexDigitToInt <$> Atto.satisfy isHexDigit
 
     hexDigitToInt c
-      | '0' <= c && c <= '9' = ord c - ord '0'
+      | isDigit c = ord c - ord '0'
       | 'A' <= c && c <= 'F' = ord c - ord 'A' + 10
       | 'a' <= c && c <= 'f' = ord c - ord 'a' + 10
       | otherwise = error $ printf "not a hex digit: %c" c
-    
-    separators = Atto.skipMany $ Atto.satisfy $ Atto.inClass " +."
+
+parseCodepoints :: Text -> Either String [Word]
+parseCodepoints = Atto.parseOnly $ codepoints <* Atto.endOfInput
+
+codepoints :: Atto.Parser [Word]
+codepoints = codepoint `Atto.sepBy` separators
+  where
+    codepoint = Atto.choice [literal, decLiteral, hexLiteral]
+
+    literal = Atto.decimal
+
+    decLiteral = Atto.char 'd' *> Atto.decimal
+
+    hexLiteral = Atto.char 'x' *> Atto.hexadecimal
+
+
+-- Common
+
+separators :: Atto.Parser ()
+separators = Atto.skipMany $ Atto.satisfy $ Atto.inClass " +."