updated directory structure

[cc1516.git] / yard.icl

diff --git a/yard.icl b/yard.icl
index 59b4e8c..9b2ec23 100644 (file)
--- a/yard.icl
+++ b/yard.icl
@@ -1,53 +1,100 @@
 implementation module yard
 
 import StdTuple
-from StdClass import Eq
+import StdClass
+import StdString
+import StdList
+import StdInt
+from Data.List import intersperse
+from Text import instance Text String, class Text(concat)
 import Data.Functor
+import Data.Either
 import Control.Monad
 import Control.Applicative
 from Data.Func import $
+import Data.Void
+
+instance toString Error where
+       toString (PositionalError l c e) =
+               concat [toString l,":",toString c,": ",e, "\n"]
+       toString (Error e) = concat ["-:-: ", e, "\n"]
 
 runParser :: (Parser a b) [a] -> (Either Error b, [a])
 runParser (Parser f) i = f i
 
+instance + Error where
+       (+) r1 r2 = r2 //TODO
+ 
 instance Functor (Parser a) where
-    //fmap f m = liftM f m
-    fmap g p = Parser \i -> case runParser p i of
-        (Right r, rest) = (Right $ g r, rest)
-        (Left e, rest)  = (Left e, rest)
+    fmap f m = liftM f m
 
 instance Applicative (Parser a) where
     pure a      = Parser \i -> (Right a, i)
-    //(<*>) sf p  = ap sf p
-    (<*>) pf p  = Parser \i -> case runParser pf i of
-        (Right f, rest) = runParser (fmap f p) rest
-        (Left e, rest)   = (Left e, rest)
+    (<*>) sf p  = ap sf p
 
 instance Monad (Parser a) where
     bind p f    = Parser \i -> case runParser p i of
         (Right r, rest) = runParser (f r) rest
-        (Left e, rest)  = (Left e, rest)
+        (Left e, _)     = (Left e, i)
 
-//some, many, optional and l
 instance Alternative (Parser a) where
-    empty       = Parser \i -> (Left ParseException, i)
+    empty       = Parser \i -> (Left $ Error "" , i)
     (<|>) p1 p2 = Parser \i -> case runParser p1 i of
         (Right r, rest) = (Right r, rest)
-        (Left _, rest)  = runParser p2 i
+        (Left e1, rest) = case runParser p2 i of
+            (Left e2, rest)  = (Left $ e1+e2, i)
+            (Right r, rest)  = (Right r, rest)
+
+//Try the parser, if it fails decorate the error with Expected of the given String and position
+(<?>) :: (Parser a b) Error -> Parser a b
+(<?>) p e = Parser \i -> case runParser p i of
+    (Left e1, rest) = (Left $ e1 + e, rest)
+    (Right r, rest) = (Right r, rest)
 
 fail :: Parser a b
 fail = empty
 
 top :: Parser a a
 top = Parser \i -> case i of
-    []      = (Left ParseException, [])
+    []      = (Left $ Error "", [])
     [x:xs]  = (Right x, xs)
 
+peek :: Parser a a
+peek = Parser \i -> case i of
+    []      = (Left $ Error "", [])
+    [x:xs]  = (Right x, [x:xs])
+
+//runs the left parser until the right parser succeeds. Returns the result of the left parser 
+//Note: if the right parser consumes input then this input is lost!
+//If the left parser fails before the right parser succeeds the whole parser fails
+(until) infix 2 :: (Parser a b) (Parser a c) -> Parser a [b]
+(until) p guard = try $ until` p guard [] 
+    where
+        until` :: (Parser a b) (Parser a c) [b] -> Parser a [b]
+        until` p guard acc = Parser \i -> case runParser guard i of 
+            (Right _, rest) = (Right acc, rest)
+            (Left _, _)     = case runParser p i of
+                (Right r, rest) = runParser (until` p guard [r:acc]) rest
+                (Left e, _)     = (Left e, i)
+        try :: (Parser a b) -> Parser a b
+        try p = Parser \i -> case runParser p i of
+            (Left e, _)     = (Left e, i)
+            (Right r, rest) = (Right r, rest)
+
+
+eof :: Parser a Void
+eof = Parser \i -> case i of 
+    []      = (Right Void, [])
+    _       = (Left $ Error "", i)
+
 satisfy :: (a -> Bool) -> Parser a a
-satisfy f = one >>= \r -> if (f r) (return r) fail
+satisfy f = top >>= \r -> if (f r) (return r) fail
+
+check :: (a -> Bool) -> Parser a a
+check f = peek >>= \r -> if (f r) (return r) fail
 
 item :: a -> Parser a a | Eq a
 item a  = satisfy ((==)a)
 
 list :: [a] -> Parser a [a] | Eq a
-list as = mapM item as
\ No newline at end of file
+list as = mapM item as