Added maths bracketing

src/Lexer.hs

@@ -29,15 +29,16 @@ data Token
   | BirdTrack
   | BoldOpen
   | BoldClose
-  | BracketOpen
-  | BracketClose
   | EmphasisOpen
   | EmphasisClose
   | MonospaceOpen
   | MonospaceClose
   | Newline
-  | ParenOpen
-  | ParenClose
+  | Escape
+  | MathsParenOpen
+  | MathsParenClose
+  | MathsBracketOpen
+  | MathsBracketClose
   | QuoteOpen
   | QuoteClose
   | Space
@@ -57,7 +58,10 @@ lexText = go
         toks <-
           choice $
             Parsec.try
-              <$> [ newlineToken
+              <$> [ mathsBracket
+                  , mathsParens
+                  , escape -- maths go before escape to avoid mismatch
+                  , newlineToken
                   , spaceToken
                   , quotes
                   , textElement
@@ -85,8 +89,6 @@ textElement =
       <$> [ emphasis
           , bold
           , monospace
-          , parens
-          , brackets
           , angles
           ]
 
@@ -110,8 +112,20 @@ delimited a b c d = delimitedMaybe a b c (Just d)
 delimitedSymmetric :: Parser a -> Token -> Token -> Parser [LocatedToken]
 delimitedSymmetric s t1 t2 = delimited s s t1 t2
 
+eol :: Parser ()
+eol = void "\n" <|> Parsec.eof
+
+mathsBracket :: Lexer
+mathsBracket = delimited (void $ "\\[") (void "\\]") MathsBracketOpen MathsBracketClose
+
+mathsParens :: Lexer
+mathsParens = delimited (void $ "\\(") (void "\\)") MathsParenOpen MathsParenClose
+
 birdTrack :: Lexer
-birdTrack = delimitedMaybe (void ">> ") (void "\n" <|> Parsec.eof) BirdTrack Nothing
+birdTrack = delimitedMaybe (void ">> ") eol BirdTrack Nothing
+
+escape :: Lexer
+escape = delimitedMaybe (void "\\") eol Escape Nothing
 
 quotes :: Lexer
 quotes = delimitedSymmetric "\"" QuoteOpen QuoteClose
@@ -125,11 +139,11 @@ bold = delimitedSymmetric "__" BoldOpen BoldClose
 monospace :: Lexer
 monospace = delimitedSymmetric "@" MonospaceOpen MonospaceClose
 
-parens :: Parser [LocatedToken]
-parens = delimited "(" ")" ParenOpen ParenClose
+-- parens :: Parser [LocatedToken]
+-- parens = delimited "(" ")" ParenOpen ParenClose
 
-brackets :: Lexer
-brackets = delimited "[" "]" ParenOpen ParenClose
+-- brackets :: Lexer
+-- brackets = delimited "[" "]" ParenOpen ParenClose
 
 angles :: Parser [LocatedToken]
 angles = delimited "<" ">" AngleOpen AngleClose