src/Lexer.hs

@@ -10,8 +10,7 @@ import Control.Monad (mfilter, void)
 import Data.Functor (($>))
 import Data.Text (Text, intercalate)
 import Data.Text qualified as Text
-import Data.Char (ord, toLower)
+import GHC.Unicode (isAlphaNum, isControl, isPrint, isSpace, isUpper)
-import GHC.Unicode (isAlphaNum, isControl, isPrint, isSpace, isUpper, isDigit)
 import ParserMonad (Parser, initialParserState)
 import Text.Parsec
 import Text.Parsec qualified as Parsec
@@ -93,7 +92,6 @@ lexText = go
                                 , labeledLink
                                 , module_
                                 , anchor
-                                , numericEntity
                                 , textElement
                                 , quotes
                                 , birdTrack
@@ -256,32 +254,6 @@ bold = delimitedSymmetric "__" BoldOpen BoldClose
 monospace :: Lexer
 monospace = delimitedSymmetric "@" MonospaceOpen MonospaceClose
 
-decimal :: Parser Int
-decimal = read . Text.unpack <$> takeWhile1_ isDigit
-
-hexadecimal :: Parser Int
-hexadecimal = "x" *> (convert 0 . fmap (normalise . toLower) <$> many1 hexDigit)
-    where
-        normalise :: Char -> Int
-        normalise c
-            | ord '0' <= n && n <= ord '9' = n - ord '0'
-            | ord 'A' <= n && n <= ord 'F' = n - ord 'A' + 10
-            | ord 'a' <= n && n <= ord 'f' = n - ord 'a' + 10
-            | otherwise = error "unexpected: invalid hex number"
-            where
-                n = ord c
-
-        convert :: Int -> [Int] -> Int
-        convert acc [] = acc
-        convert acc (x : xs) = convert (acc * 16 + x) xs
-
-numericEntity :: Lexer
-numericEntity = do
-    x <- located $ between "&#" ";"
-            ( NumericEntity <$> (hexadecimal <|> decimal)
-            )
-    pure [x]
-
 other :: Lexer
 other = do
     pos <- getPosition

test/Spec.hs

@@ -30,7 +30,6 @@ main = hspec $ do
             it "bird tracks" birdTracks
             it "module names" modules
             it "quotes" quotes
-            it "numeric entity" numericEntity
             it "ignores nesting" ignoreNesting
 
     describe "Parser" do
@@ -153,18 +152,6 @@ space = do
                       , (1, 2, Newline)
                       ]
 
-numericEntity :: Expectation
-numericEntity = do
-    "A λ"
-        `shouldLexTo` [ (1, 1, NumericEntity 65)
-                      , (1, 6, Space)
-                      , (1, 7, NumericEntity 955) -- lambda
-                      ]
-    -- Hex
-    "e"
-        `shouldLexTo` [ (1, 1, NumericEntity 101)
-                      ]
-
 monospace :: Expectation
 monospace =
     "@mono@"