Update demos and adds <|

src/Lexer.hs

@@ -45,6 +45,7 @@ tricuLexer = do
       , closeParen
       , openBracket
       , closeBracket
+      , try arrowLeft
       ]
 
 lexTricu :: String -> [LToken]
@@ -128,6 +129,9 @@ openBracket = char '[' $> LOpenBracket
 closeBracket :: Lexer LToken
 closeBracket = char ']' $> LCloseBracket
 
+arrowLeft :: Lexer LToken
+arrowLeft = string "<|" $> LArrowLeft
+
 lnewline :: Lexer LToken
 lnewline = char '\n' $> LNewline
 

src/Parser.hs

@@ -112,8 +112,8 @@ parseExpressionM = choice
   , try parseLambdaM
   , try parseLambdaExpressionM
   , try parseListLiteralM
-  , try parseApplicationM
   , try parseTreeTermM
+  , try parseArrowLeftM
   , parseLiteralM
   ]
 
@@ -138,7 +138,7 @@ parseLambdaM = do
 
 parseLambdaExpressionM :: ParserM TricuAST
 parseLambdaExpressionM = choice
-  [ try parseLambdaApplicationM
+  [ try parseLambdaArrowLeftM
   , parseAtomicLambdaM
   ]
 
@@ -172,6 +172,34 @@ parseLambdaApplicationM = do
     pure arg
   pure $ foldl SApp func args
 
+parseArrowLeftM :: ParserM TricuAST
+parseArrowLeftM = do
+  left <- parseApplicationM
+  mArrow <- optional (try $ do
+    scnParserM
+    satisfyM (== LArrowLeft))
+  case mArrow of
+    Nothing -> return left
+    Just _ -> do
+      skipMany (satisfyM (== LNewline))
+      scnParserM
+      right <- parseExpressionM
+      return $ SApp left right
+
+parseLambdaArrowLeftM :: ParserM TricuAST
+parseLambdaArrowLeftM = do
+  left <- parseLambdaApplicationM
+  mArrow <- optional (try $ do
+    scnParserM
+    satisfyM (== LArrowLeft))
+  case mArrow of
+    Nothing -> return left
+    Just _ -> do
+      skipMany (satisfyM (== LNewline))
+      scnParserM
+      right <- parseLambdaExpressionM
+      return $ SApp left right
+
 parseAtomicBaseM :: ParserM TricuAST
 parseAtomicBaseM = choice
   [ parseTreeLeafM

src/Research.hs

@@ -49,6 +49,7 @@ data LToken
   | LCloseBracket
   | LStringLiteral String
   | LIntegerLiteral Int
+  | LArrowLeft
   | LNewline
   deriving (Eq, Show, Ord)