Handle ending ;

[kaleidoscope-hs-old.git] / AST.hs

diff --git a/AST.hs b/AST.hs
index 720413652e4343740ad6268e0a866b0576e4c4aa..6b9928d5b13fa0d67c848b8c3c0e446c2babb4f4 100644 (file)
--- a/AST.hs
+++ b/AST.hs
@@ -8,10 +8,14 @@ newtype Program = Program [AST]
   deriving Show
 
 instance Read Program where
-  readPrec = fmap Program $ lift $ sepBy1 (readS_to_P reads) $ do
+  readPrec = fmap Program $ lift $ do
+    asts <- sepBy1 (readS_to_P reads) $ do
       skipSpaces
       char ';'
       skipSpaces
+    optional $ char ';'
+    skipSpaces
+    return asts
 
 data AST = Function String [String] Expr
          | Eval Expr
@@ -39,7 +43,8 @@ instance Read AST where
             return (Function name params body)
 
 instance Read Expr where
-  readPrec = choice [ parseNum
+  readPrec = choice [ parseParens
+                    , parseNum
                     , parseVar
                     , parseCall
                     , parseIf
@@ -50,7 +55,9 @@ instance Read Expr where
                     , parseBinOp "<" (Cmp LT)
                     , parseBinOp "==" (Cmp EQ)
                     ]
-    where parseNum = Num <$> readPrec
+    where parseParens = step $ lift $
+            between (char '(') (char ')') (readS_to_P reads)
+          parseNum = Num <$> readPrec
           parseVar = Var <$> lift (munch1 isAlpha)
           parseCall = do
             func <- lift (munch1 isAlpha)