From 0888ae35770f9d3d269bb2345db016137dea7b92 Mon Sep 17 00:00:00 2001
From: Mart Lubbers <mart@martlubbers.net>
Date: Mon, 28 Jan 2019 15:42:31 +0100
Subject: [PATCH] parserparser

---
 parserParser/test.icl | 24 +++++++++++++++---------
 1 file changed, 15 insertions(+), 9 deletions(-)

diff --git a/parserParser/test.icl b/parserParser/test.icl
index 26a91d5..fb2eafa 100644
--- a/parserParser/test.icl
+++ b/parserParser/test.icl
@@ -14,38 +14,38 @@ import Text.Parsers.Simple.Core
 :: In a b = (:.) infix 0 a b
 
 :: Gram
-//	= Def (Gram -> In Gram Gram)
-//	| Def2 ((Gram,Gram) -> In (Gram, Gram) Gram)
 	= Lit String
 	| Int
 	| (-.) infixr 2 Gram Gram
 	| (|.) infixl 1 Gram Gram
 	| *! Gram
+	| ?! Gram
+Lits = foldr1 (|.) o map Lit
+foldr1 f [x:xs] = foldr f x xs
 :: Gast
 	= INT Int
 	| LIT String
 	| BIN Gast Gast
+	| OPT (Maybe Gast)
 	| MANY [Gast]
 
 parseFromGram :: Gram -> Parser String Gast
 parseFromGram  Int     = INT o toInt <$> pSatisfy (\s->toString (toInt s) == s)
 parseFromGram (Lit i)  = LIT <$> pSatisfy ((==)i)
+parseFromGram (?! g)   = OPT <$> optional (parseFromGram g)
 parseFromGram (*! g)   = MANY <$> many (parseFromGram g)
 parseFromGram (a -. b) = BIN <$> parseFromGram a <*> parseFromGram b
 parseFromGram (a |. b) = parseFromGram a <|> parseFromGram b
 
 //Start = runParser (parseFromGram gram) [".","."]
-Start = printeval <$> parse (parseFromGram gram) ["4","-","2","-","1"]
+Start = printeval <$> parse (parseFromGram gram) ["4","*","2","*","1","*","(","3","^","3","^","3",")"]
 where
 	gram =
 		let lit  =  Lit "(" -. expr -. Lit ")"
 		         |. Int
-		    pow  =  lit -. Lit "^" -. pow
-		         |. lit
-		    fac  =  pow -. *! (Lit "*" -. pow)
-		         |. pow
-		    expr =  fac -. *! (Lit "-" -. fac)
-		         |. fac
+		    pow  =  lit -. ?! (Lit "^" -. pow)
+		    fac  =  pow -. *! (Lits ["*","/"] -. pow)
+		    expr =  fac -. *! (Lits ["+","-","%"] -. fac)
 		in  expr
 
 	printeval a = (eval a, print a)
@@ -54,6 +54,8 @@ where
 	eval (BIN (LIT "(") (BIN e (LIT ")"))) = eval e
 	eval (INT i) = Just i
 	eval (LIT _) = Nothing
+	eval (BIN l (OPT Nothing)) = eval l
+	eval (BIN l (OPT (Just a))) = eval (BIN l a)
 	//Right associative operators
 	eval (BIN l (BIN (LIT op) r)) = op2op op <*> eval l <*> eval r
 	//Left associative operators
@@ -66,6 +68,8 @@ where
 	print (BIN (LIT "(") (BIN e (LIT ")"))) = "(" +++ print e +++ ")"
 	print (INT i) = toString i
 	print (LIT l) = l
+	print (BIN l (OPT Nothing)) = print l
+	print (BIN l (OPT (Just a))) = print (BIN l a)
 	//Right associative operators
 	print (BIN l (BIN (LIT op) r)) = "(" +++ print l +++ op +++ print r +++ ")"
 	//Left associative operators
@@ -77,6 +81,8 @@ where
 	op2op "+" = Just (+)
 	op2op "-" = Just (-)
 	op2op "*" = Just (*)
+	op2op "/" = Just (/)
+	op2op "%" = Just (rem)
 	op2op "^" = Just (^)
 	op2op _ = Nothing
 
-- 
2.20.1